Article Details

- Battery Technology
- Truck
Construction of VARTA Promotive EFB Truck Batteries

The new wet battery for trucks
Since its launch in 2014 the VARTA^® Promotive EFB battery has brought the performance of wet batteries to a new level. In modern long distance trucks, the large number of consumers and the resulting increase in depth of discharge presents a challenge for all conventional wet batteries.
The reason is acid stratification, which occurs with all wet batteries.
Why is acid stratification a problem?
The phenomenon of acid stratification occurs whenever batteries with liquid electrolyte are regularly discharged and recharged. The deeper a battery is discharged, the more rapidly acid stratification becomes a problem. However, in the long term a large number of flat cycles or deep discharge of the battery results in acid stratification. This is an uneven distribution of acid density within the battery cell. Acid with a higher concentration accumulates in the lower areas of the cell. Less concentrated electrolyte remains in the upper area. This causes three undesirable effects:

1. The highly concentrated acid in the lower part of the cell attacks the active mass of the battery and the lead grilles. This reduces the service life of the battery.

2. Because of acid stratification the open circuit voltage increases so that the battery management system incorrectly assumes that there is a higher charge level. This can cause additional stress on the battery due to an incorrect strategy by the battery management system (BMS), which causes premature battery failure.

3. Because of the increased open circuit voltage, charge acceptance is also drastically reduced, which can result in low charge so that the battery fails earlier.

4. Due to the different acid densities an internal charge transfer process occurs in the plates of the individual cells. As a result, part of the active mass is increasingly and permanently damaged due to sulfation and is no longer available. This reduces the available capacity and also dramatically reduces the cold start performance of the battery.

All three points cause premature battery failure and additional maintenance costs through more frequent battery replacement.
VARTA^® ProMotive EFB Batteries – a revolutionary solution
The solution which our engineers produced to eliminate the problem of acid stratification is the patented mixing element. The mixing element is located on the side of each cell and utilises natural movement of the vehicle to mix the acid. As the mixing element does not have any moving parts, wear is not a problem. Circulation of the electrolyte is achieved solely by steering movements, acceleration or braking and vibration of the vehicle. In this way, the electrolyte in the cell is constantly in motion. Due to a special design, the mixing element in the VARTA^® Promotive EFB battery utilises two basic physical principles (Link to Wikipedia article about 1: communicating vessels, 2: Bernoulli effect), to cause a turbulent flow within each cell. During the entire journey this flow ensures continuous circulation so that acid stratification does not occur during charging by the generator. In practice, with conventional wet batteries without a mixing element normal movement of the acid is not sufficient to prevent acid stratification.
Performance of VARTA^® ProMotive EFB batteries repeatedly confirmed
Various laboratory tests and field trials have shown that the VARTA^® Promotive EFB can meet much higher requirements than conventional wet batteries, which significantly increases their service life in the vehicle. The positive feedback from our original equipment manufacturers and the results of independent tests and reports also prove that with the Truck EFB we have a high performance solution for the requirements of long distance transport in our portfolio. The Truck EFB is a further example of the innovative strength of the VARTA^® Automotive brand. We develop battery solutions for the fleets of today and the future.

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- Battery Technology
- Truck
The importance of charge acceptance of truck batteries

The importance of a good cold start value (CCA) and a high usable capacity (C20) for truck batteries is now common knowledge. Most fleet operators know that only truck batteries with a high cold start potential and adequate capacity can ensure reliable fleet operation.
Modern hoteling functions need power
For some time, truck batteries have been subjected to greater demands. In the past they were mainly used for starting and were charged by the generator while driving. This situation has changed considerably over the past decade. A large amount of electronic equipment which assists in the safety, environment and driver comfort all contributes to the increased load on the truck battery. As well as this: Driver loyalty is becoming increasingly important, because fleet operators face a shortage of 35,000 truck drivers. Companies cannot afford to make savings with equipment if they do not want to lose drivers to their competitors. The large number of consumers in the truck have an effect on the requirements of fleet operators for the batteries. A truck battery is a component which is too important to be neglected.
Charging times are reducing, but power demands are growing
When the engine is off, the battery is discharged faster and more deeply due to the large number of electrical consumers. Therefore it must be charged with greater current and more frequently. Although the battery is charged by the generator while driving, it has to share a large proportion of the power which is supplied by the generator with the electrical consumers. If the light, the refrigerator and the radio have to be supplied in the truck, the amount of power to charge the battery is reduced.
Many modern trucks are equipped with functions which help to save fuel and improve efficiency. About 35% of total fleet costs result from fuel consumption. To improve fuel efficiency downhill travel and braking are used to charge the battery. On the other hand when traveling uphill and accelerating the engine should operate with the highest possible efficiency. This is achieved by decoupling the alternator, known as passive boost. When coasting, the sailing function switches off the engine and decouples it from the drive train. This not only means that the time which is available for charging the battery is reduced, but also that in these phases the battery has to supply all of the electrical consumers.
Charge acceptance – a critical factor for older batteries
With older batteries, the charge acceptance is often inhibited. An essential reason for the gradual deterioration of charge acceptance is sulfating, which reduces the active surface of the plates in the battery cells. The usual driving time of the truck is therefore no longer sufficient to ensure complete recharging of the battery. However, during the next few overnight stays, the battery should once again provide sufficient energy for lighting, the refrigerator and the coffee machine. Premature failure of a comfort function such as TV or the kettle may only be annoying, but if the truck fails to start the next morning, this often has negative consequences for scheduling and customers.
On the safe side with VARTA^® truck batteries
The innovative features of the new generation of VARTA^® truck batteries are designed to meet the increased demands in a modern truck and ensure a permanently high charge acceptance. With the patented PowerFrame^® technology and use of glass fleece separators in VARTA^® AGM batteries, fleet operators are in an ideal position to cope with the increased demand for electrical power in everyday logistics. In the VARTA^® EFB battery, the patented mixing element ensures high charge acceptance and a long service life.

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- Battery Basics
Battery tips for the leisure season
Getting your leisure vehicle ready for the start of the season
In contrast to conventional vehicle batteries which are used all year round, leisure batteries are mostly in-use during spring and summer. For seasonal use, it is particularly important to take good care of the battery’s condition. If a battery is not used for a long period of time, it might deteriorate, and it may need to be replaced. In these cases, the battery has not failed due to a manufacturing or material defect, but due to a lack of care and maintenance. In this article, you will learn our tips & tricks and gain some useful knowledge that will get you through the season without a breakdown.
Different technologies for different applications
SLI (Starting, Lighting, Ignition) batteries deliver an extremely high current output for brief periods. This starting power is the primary requirement of an SLI battery which is measured in Cold Cranking Amperes (CCA). Marine Cranking Amperes (MCA) is the corresponding measurement in the marine industry. Starter batteries are not designed to withstand extensive discharge/charge cycles.
Batteries for leisure applications deliver a constant current over a long period of time. Unlike an SLI battery, these batteries can be discharged and recharged repeatedly without these cycles causing damage or shortening the service life. They are well suited for powering numerous electronic, plug-in accessories and other applications that place high demands in boats, caravans, or motorhomes.
The VARTA^® Professional range offers service batteries (also known as dual purpose) with both AGM and EFB technology. EFB batteries were introduced as a lower tier option to AGM batteries in terms of performance and cycle life. EFB technology is based on improvements to the existing flooded battery technology, e.g. by adding carbon additives during plate manufacture. AGM batteries have the advantage of unique design features not found in flooded batteries. They have a long service life, very good vibration resistance and are completely maintenance-free as they do not consume any water and are leak-proof. AGM batteries are ideally suited to meet the demands of high-end caravanning vehicles and boats.
Maintenance tips & tricks
When the battery is not in use, there are a few things to consider. Follow these tips prior, during and after the rest period to get the most out of your VARTA battery.
Prior to the rest period
➤ Charge the battery completely, switch off all electrical devices and, if possible, disconnect the battery➤ Store in a cool, dry place
➤ Store batteries fully charged; fully charged batteries can be stored even at temperatures well below zero
➤ Partially charged batteries can freeze
During the rest period
➤ Check the state of charge/voltage regularly
➤ Should the voltage drop below 12.4 V, recharge the battery completely by using a charger suitable for the battery in question
After the rest period
➤ Fully recharge the battery and, if applicable, reconnect the electrical devices
➤ Check that still everything works
Sources of battery failure
Understanding the factors contributing to battery failure is crucial for maintaining optimal battery performance. Here are some insights to help you safeguard your battery and ensure its longevity.
- Lights, fans and other technical devices on standby mode can slowly drain the battery
- Corroded terminals, cable connections and cables with a high electrical resistance can lower the charge current
- A defective battery charger can lead to overcharging or partial charging
- The charging capacity of a charger should not be exceeded by the capacity requirements of the electrical devices
- Short circuits or defects in the boat’s or vehicle’s electrical system
- Partially charging an empty battery
- Long vehicle rest periods without disconnecting the battery
- With applications that do not sufficiently mix the electrolyte (e.g. boats on inland waterways, caravans, solar or stationary applications), there is a risk of acid stratification, so we recommend a battery with AGM technology
Choosing the right battery for your journey
It may sound obvious, but choosing the right battery with the right specification and technology tailored to the specific requirements is crucial. Using the wrong battery will result in a short service life. To make the right battery choice even easier, we have created and developed the VARTA^® Leisure Battery Finder. With an intuitive graphical user interface, this handy tool will guide you step by step to the battery that is perfectly suited for your purposes – whether you are going camping or exploring the open seas.
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- Battery Technology
- Workshop Knowledge
Voltage stabilization during battery exchange

When the engine is switched off, power is still drawn from the battery during vehicle diagnostics. In the case of a longer diagnosis, the battery installed in the vehicle can be discharged by the control units and other electrical loads to such an extent that the on-board system voltage falls below the permissible under-voltage limit of the control units and a corresponding entry is made in the fault memory and data is lost in the volatile memory section (e.g. steering angle sensor or end positions of the electric window lifters).

A constant voltage of the vehicle electrical system is therefore a prerequisite for professional troubleshooting or battery replacement and to avoid additional difficulties from the outset due to any undervoltage.
What is voltage stabilization?
Voltage stabilization describes the process of connecting an external power supply in order to maintain the voltage in the vehicle at a constant level when the battery is disconnected. This prevents the control units in the vehicle from registering a critical undervoltage and recording this as a fault in the event record.
“Mercedes sometimes reacts sensitively to this if you simply disconnect the battery and connect a new one: We already had a head up display that no longer works and problems with driver assistance systems. You have to use a diagnostic tool for that anyway. It could also affect the start/stop behaviour for a longer period of time.”
R. Nickel – CLARIOS Vehicle Application Engineer
Recommendation for voltage stabilization
The external power supply shall be connected before starting battery replacement or extended vehicle diagnostics.
NOTE: Never use a car battery charger to maintain voltage. Modern chargers use a special charging algorithm with different phases of charging. Sudden disconnection of the battery can lead to malfunctions in the charger, which can damage the vehicle electronics or charger.
When changing the battery, do not disconnect the installed battery until the external power supply has been connected and switched on.
The external voltage source must always be connected at points that are capable of safely carrying the required currents. For this reason, we always recommend connecting the external voltage source to the battery connection terminals for diagnostic purposes.
In the event of a battery change, the connection to the battery terminals is naturally somewhat more difficult to handle. Working on the cables can also cause the clamps of the external voltage source to drop or cause short circuits. If available, we recommend using the jump start connection points in the vehicle in this case. Information on where these are in the vehicle can be found in the VARTA Partner Portal.
NOTE: We advise against connecting the voltage maintenance via the OBD interface. According to the ISO 15031-3 specification, the maximum current carrying capacity of the connections is limited to 10A - a value that can quickly be exceeded if several control units wake up. This can lead either to serious and expensive damage to the OBD interface or to the fuse being blown, unnecessarily delaying diagnostic or repair work.
The easiest way certainly is to use a second battery as a secondary power source. With this approach, it is important to make sure that the system is protected against unintentional short circuits by a suitable fuse.
In everyday workshop use, stationary constant power supplies with sufficient power from 350W have proven their worth. In this power class, even the unintentional wake-up of one or more control devices does not immediately lead to a breakdown of the supply voltage.
Conclusion
Whenever a battery change or an extensive troubleshooting needs to be performed an additional voltage stabilization should be ensured. Always try to connect the external power source to the battery connection terminals. If this is difficult to handle we recommend using the jump start connection points. Beware of short circuits. Never use a voltage maintenance via OBD. Better go with a secondary battery or a constant voltage power supply of at least 350W instead.
You want to learn more about the different electrical systems in modern vehicles? Then our Advanced Automotive Training is definitely the right thing for you!

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- Workshop Knowledge
The right code of the BEM for Battery replacement
No modern vehicle is without the familiar comfort functions, such as air conditioning, entertainment systems, heated seats, power windows, etc., which are highly appreciated by the driver and passengers and must also function during start-stop events. In addition to this, the latest vehicles are increasingly equipped with safety-related driver assistance systems such as lane assist, automatic distance control or brake assist and other functions. Automakers use sophisticated battery management systems that continuously monitor the battery to ensure the necessary availability of these comfort and safety functions.

If a battery now needs to be replaced, it needs to be reprogrammed into the vehicles energy management system. Why is this important? An aged worn out battery shows a different behaviour with regards to available capacity, energy output and charge acceptance then a new unused one. The Battery Management System (BMS) together with the Electronic Battery Sensor (EBS) monitors the battery over its lifetime. It detects e.g. the number of starts and the energy flow (Ah throughput), monitors the state of charge, controls the charging and adapts the energy management of the battery over the time dependent of its state of health.

If the reprogramming is not carried out correctly it can cause restriction or even failure of the start-stop function, which can result in increased fuel consumption and restriction of comfort functions.
Different ways of battery coding
Nowadays we can see in the market that OE car manufacturer follow different strategies to reprogram new batteries in their vehicles BMS.
SELF LEARNING: As a first group there are self-learning systems. Here the BMS comes with only one or a few preprogramed battery options per vehicle which the BMS will use as a reference. After battery replacement the BMS compares over the time the actual new battery performance with the battery references stored in the BMS memory and will learn which of the stored references fits to the actual measured performance. OEs following this strategy are for instance Abarth, Alfa Romeo, Chevrolet (Daewoo), Citroen, Dacia, Fiat, Honda, Lancia, Mercedes, Mitsubishi, Peugeot, Renault, Subaru, Suzuki, Toyota and Volvo.
REGISTRATION WITH DIAGNOSTIC TOOL: A second group of OE car manufacturer require an active registration of the new replacement battery into the vehicles BMS and with it the use of a diagnostic device for reprogramming. Just to give some examples we can name Alpina, Audi, BMW, Jaguar, Jeep, Land Rover, Mazda, Mini, Seat, Skoda and Volkswagen. And within this group some vehicle manufacturers like the VAG group or BMW require a code to register the new battery during replacement. The codes are not only OE but also battery specific.
The VAG specific BEM code is basically a two line code. The first line contains the OE spare part number. This number is different for OES (i.e. 000915105DG) and OEM (i.e. 4F0915105E) channel but limited to the amount of battery types VAG uses. The second line codes the battery manufacturer, the manufacturing date of the battery and contains a part making this code specific.
OES BEM-Code

OEM BEM-Code

NOTE: The QR code printed on the VARTA^® AGM and EFB batteries is used for internal purposes only. It does not contain the same information as an OE BEM code, and therefore cannot be used as a replacement of the OE BEM code to register new batteries in VAG vehicles.
Depending on the IAM diagnostic tools some request the BEM code for battery replacement. In this case for VAG it is required to insert both lines of the BEM code of the new battery.
Others diagnostic tools like Hella Gutmann or BOSCH KTS create the required battery specific information using drop-down options. Entering the BEM code is not required. You just need to select the capacity, manufacturer and technology. The serial number requested is just for traceability purpose. Any 10 digit number can be applied.
The following example shows a battery coding in a Škoda KODIAQ 1.5 TSI using a BOSCH KTS diagnostic device. After vehicle selection you need to choose the menu path for battery replacement and use the right parameter from the drop-down.
By running this process the monitored battery usage counter in the BMS will be reset to zero. Regarding battery capacity and technology we always recommend a ‘like-for-like’ or ‘better-for-like’ replacement. Never downsize the replacement battery!
Basically the same procedure is applied when using the Hella Gutmann diagnostic device.
If you use the VCDS for battery replacement in VAG vehicles or vehicles using VW technology there is a slightly different procedure depending on whether the vehicle is equipped with control unit 61. In this case you need to select control unit ’61 battery control’ and after that the right menu path. Here you can insert the needed OE spare part number and a 10 digit serial number. As we recommend to replace ‘like-for-like’ you can stay with the original OE spare part number if you replace the original battery with the same technology and performance. Slight deviations of the ratings is not a problem. If you replace ‘better-for-like’ you need to take the OE spare part number corresponding to the new battery chosen. For the requested serial number any 10 digit number can be applied.
In alternative it is also possible to reprogram the new battery into the vehicles BMS by selecting the battery parameters manually. The approach is quite similar to the BOSCH KTS or Hella Gutmann tools.
The following example shows this approach of battery coding in a Škoda KODIAQ 1.5 TSI using a VCDS diagnostic device.
By adjusting of one of the four battery values (capacity, technology, manufacturer, serial number) the monitored battery usage counter of the BMS will be reset to zero. The serial number always needs to be changed to address the new battery. But it is also possible to change the serial number back to the original one afterwards. So finally the new battery is programmed into the BMS but the original serial number stays.
COMBINED APPROACH: And there is a third group of manufacturers who follow both strategies dependent on the specific model. OEs to be mentioned are Ford, Hyundai, Kia, Lexus, Nissan, Opel, Porsche, Smart and Vauxhall
Battery coding without a tool
As a special case Ford needs to be mentioned as they offer for some models a BMS battery reset which not necessarily requires a diagnostic device. It can be done manually by a certain vehicle specific combination of dashboard buttons and switchers.
Vehicle with rear fog light:
Steps need to be run within 10 seconds.
1. Switch on the ignition
2. Press the rear fog light button 5 times
3. Then press the warning flasher switch 3 times
If the red battery charge indicator light in the instrument panel flashes 3 times within 15 second the reset was successful.
Vehicle without fog light:
Steps need to be run within 10 seconds.
1. Switch on the ignition
2. Press the headlight flasher 5 times
3. Then fully depress the brake pedal 3 times
If the red battery charge indicator light in the instrument panel flashes 3 times within 15 second the reset was successful.
This procedures reset the day count of the battery use. A fine calibration of the BMS is then made when the vehicle is closed for at least 3 hours.
Conclusion
Although in every modern vehicle with a BMS the battery replacement needs to be addressed, the topic itself is not as complicated as it appears at a first glance. Many car brands do not even require an active recoding as the system recognize the new battery by itself. Other car manufacturer require a tool to do so. But with sophisticated devices available in the independent aftermarket it is easy to run this process.
You want to learn more about the different electrical systems in modern vehicles? Then our Advanced Automotive Training is definitely the right thing for you!
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- Battery Technology
- Truck
Varta® truck batteries are robust
1. The space between the axles is used for a larger tank. This improves both range and economy, especially in countries with high fuel prices. As well as this, fewer refueling stops reduce journey times and facilitate scheduling.
2. The truck's SCR catalyst reduces nitrous oxide emissions by 95% and makes transportation of goods by road future-proof. However, the urea tank which is needed to operate the catalyst also takes up space. This is another reason why in many new trucks the battery is integrated into the area of the rear axle.
At the rear end of the truck there is even enough space for two large batteries. However, the location at the rear end of the tractor unit also causes additional stress on the battery. The shocks and vibrations which act on the rear axle are also transferred to the battery.
New challenges for truck batteries
In addition to the increased vibration and shocks due to the position above the drive axle, truck batteries are also subjected to stresses due to other mechanical factors. Location at the rear can amplify unwanted oscillations and resonances. With conventional battery designs the continuous vibration can considerably reduce the life of the truck battery. Thanks to special constructional features, batteries for end-of-frame installation are equipped to deal with the increased vibration requirements.
This can be identified from the "END OF FRAME INSTALLATION" symbol on the battery
VARTA^® truck batteries meet the highest requirements of the current standard.
In order for truck batteries to meet the requirements of modern long distance goods transport the European battery standard EN50342 has been revised. According to the test which is specified in directive V3, a truck battery must withstand a 20-hour vibration test in a spatial axis at a frequency of 30 Hz. Since the revision of the standard there is now a new requirement V4, which allows for the increased vibration requirements.
The new directive V4 achieves a better approximation to real-life operation. Truck batteries must withstand a five-hour vibration test in all three spatial axes over a frequency spectrum from 5 to 100 Hertz. Only a few batteries on the market withstand this severe test. These include the VARTA^® Truck AGM battery and the VARTA^® Truck EFB battery.
Planning security through reliability
For fleet managers, reliable and robust truck batteries are an important prerequisite for economical operation and reliable planning of the fleet. Since the introduction of the VARTA^® Truck EFB premature failures due to vibration are a thing of the past. With long-life, vibration resistant truck batteries from VARTA^® fleet operators are on the safe side in future.
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- Battery Technology
- Truck
AGM truck batteries in detail

However, it represents a significant breakthrough in commercial vehicle battery development. Renowned manufacturers demand for proven high quality original equipment. Using the latest AGM technology, this innovative product meets all of these requirements. Let’s take a look inside an AGM battery.
AGM battery technology
The AGM truck battery is the result of many years of expertise gained by VARTA^® in the production of start-stop batteries. Our plants in Germany have supplied vehicle manufacturers and workshops around the world with more than 70 million AGM batteries since production began in 2003. The abbreviation AGM stands for Absorbent Glass Mat which refers to the glass fleece separator binding the acid and at the same time separates the positive and negative plates.
A unique feature of the VARTA^® AGM battery is the PowerFrame® design. The VARTA^® ProMotive AGM battery uses the PowerFrame grid for the first time on both the positive and negative plates. The PowerFrame grid design is optimised for maximum performance and ensures excellent starting characteristics even with low charge levels. AGM technology is associated with an elaborate and technically sophisticated production process. When manufacturing conventional wet batteries, the battery acid is filled through openings in the cover at the end of the production process. This would not work with a Truck AGM battery. A special method is required here in order to insert the electrolyte into the glass fleece separators. This is achieved by generating a vacuum in the battery case, which then draws the acid into the separators and ensures optimum and even distribution.
Innovation with precision
Compression within the cells is another important factor concerning AGM batteries. The plates and separators must be pressed together with the correct pressure. This pressure must be neither too high nor too low in order for the battery to achieve optimum performance. A reinforced battery case has been developed to ensure uniform compression over the battery’s lifetime. This is used exclusively for VARTA^® Truck AGM batteries.
Even non-specialists can see the high compression in the cells from the curved walls of the casing. This curvature is normal and indicates the correct function of the battery cells. Another special feature of AGM technology: Each cell is a closed system. This means that each individual cell is closed with a separate valve, which safely releases the gas generated during charging via a central degassing system with ignition protection. If there is no excess pressure the valve seals the cell completely so that no oxygen can enter the cell from the outside. This is important because the plates are not surrounded by free acid. Without a valve, oxygen could come into contact with the plates, which would result in the cells discharging and premature failure. This system of closed cells is unique to AGM and contributes to the high performance and reliability of AGM Truck batteries.
Teamwork for best performance
From the first prototype to the series-production product, our engineers, project managers and professionals in the factory and the development department have worked together closely to make the AGM battery ready for series production. This battery sets new standards with regard to performance, reliability and quality for cycle-stable truck batteries. Extensive experience in the field of AGM technology, the right manufacturing process and furthermore our close contact with commercial vehicle manufactures has guaranteed the success of this project and the series-production product.

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- Truck
- Battery Basics
What is a charging cycle, and why are there increasingly more of them?

If half of the battery charge is discharged and then recharged, this is referred to as a 50% charging cycle. If the battery is fully discharged and then re-charged, this is a hundred percent charging cycle. Complete discharge of the battery should always be avoided, because this considerably shortens the life of the battery and also not enough energy is available to start the engine. However: In many fleets it can now be seen that truck batteries have to deal with more frequent and deeper discharges than was previously the case. Why is the number of charging cycles increasing and how does this affect the life of the battery?
Fleet managers are under pressure
There is a definite link between charging cycles and the cycles of loads and goods. For modern industrial countries long distance road transport is an important basis for wealth and growth. The economy is only kept moving by continuous deliveries to companies and traders. Requirements by businesses and consumers have increased. Orders which are placed today need to be delivered tomorrow. From the point of view of fleet managers the challenges are also increasing. For many years the transport of goods by road has been subject to a high pressure on costs. Sustainable profits can only be achieved with efficient route planning and short intervals. Under these conditions, the driver's cab in the truck is used more often as a hotel for the driver. At the same time, the long-term trend toward "rolling warehouses" allows little room for optimum vehicle maintenance.
Trucks with hoteling function provide comfort
If the trucks are equipped with modern comfort functions driver satisfaction and loyalty increases. Companies are also well aware of this, so that modern trucks are like small mobile hotels. TV, coffee machines and parking cooler make long stays in the cab more pleasant. However, the large number of electrical consumers also drains the battery. Almost continuous use of the battery results in increased wear. Similar to car tyres, which wear more quickly on a taxi which is in use day and night than on a private car, a truck battery is also subjected to greater stresses. This sometimes gives the impression that modern batteries are of poorer quality than they used to be. The actual reason for greater wear and shorter life is the more intensive use of the truck battery.
VARTA^® – The truck battery professionals
At VARTA^® Automotive we have recognised the challenges and together with leading commercial vehicle manufacturers we have developed a new generation of AGM and EFB batteries. With these innovative technologies we ensure that in spite of the increased demands, maintenance of truck batteries remains as little as possible. This way your fleet can also be reliably provided with electrical power in the future.

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- Battery Technology
- xEV
Electric vehicles and the 12V battery
Different types of electric cars and their dependence on the 12V battery
The success of the automobile as a means of individual transportation began in 1913, with the introduction of the then revolutionary assembly line production by Henry Ford. Even a century later, most cars on our roads are still based on the principle of the internal combustion engine, which has been continuously improved by engineers and nowadays combines high performance, low consumption, and long durability.
Increasingly complex engine technology and, at the same time, stricter emissions regulations have triggered a technological leap that has led to the electrification of the drivetrain today. But not all electric vehicles on the market are the same. Depending on the requirements and vehicle segment, there are different approaches to electrified mobility.
What is an xEV?
As the variety of electrified drivetrains has increased in recent years, a modular abbreviation system has been created to keep track of and describe the different variants more selectively. Electric vehicles of any kind can generally be referred to as an "xEV". The ending "EV" stands for electric vehicle and is the basis for all terms. The "x" is a placeholder for the drivetrain concepts.
- HEV – Hybrid Electric Vehicle
- PHEV – Plug-in Hybrid Electric Vehicle
- BEV – Battery Electric Vehicle
- FCEV – Fuel Cell Electric Vehicle
Hybrid Electric Vehicles. The best of both worlds?
The term hybrid only means that there is more than one energy source for the operation of the vehicle. In fact, vehicles with Start-Stop technology are already considered "micro-hybrid" vehicles, because here the 12V battery acts as a second energy source when the engine is switched off.
The evolution of the "micro-hybrid" was the so-called "mild-hybrid", in which a 48V Li-ion battery is installed to supply particularly energy-hungry consumers. Although these two systems are already called hybrids, they lack a crucial feature that has long been associated with "hybrid electric cars": Purely electric driving without the aid of the combustion engine.
The difference between Full Hybrid and Plug-in Hybrid Vehicles
The term "Hybrid Electric Vehicle" actually describes two different concepts. The "Full Hybrid Electric Vehicle" (FHEV, usually abbreviated to HEV) and the "Plug-in Hybrid Vehicle" (PHEV). Both approaches share the fact that the vehicles have a high-voltage lithium-ion battery and can thus be driven purely electric.
The difference between the two systems lies in the charging strategy for the high-voltage battery. In an HEV, the battery can be charged exclusively by the combustion engine or by brake energy recovery (recuperation). In a PHEV, the battery can also be charged at a charging station, as in a purely Electric Vehicle, hence the term "Plug-in". Due to the limited charging possibilities, the capacity of the drive battery in an HEV is generally smaller than in a PHEV. Due to the lower capacity of the battery, the distances that can be covered purely electrically are also shorter for an HEV than for a PHEV.
Configuration of an HEV with internal combustion engine and electric drive, fuel tank and lithium-ion high-voltage battery.
1. 12 Volt Battery
2. DC/DC Converter
3. High-voltage Battery
4. AC/DC Converter
5. High-voltage traction motor
6. Petrol or diesel tank
7. Internal combustion engine
PHEV body, with smaller fuel tank but larger battery with external charging port for longer electric range.
1. 12 Volt Battery
2. DC/DC Converter
3. High-voltage Battery
4. AC/DC Converter
5. High-voltage traction motor
6. Petrol or diesel tank
7. Internal combustion engine
8. Electrical power source (charging station/wall box)
Both systems enable purely electric and thus local emission-free driving. Thanks to the additional combustion engine, the vehicle can also be used for long distances without restrictions. If the combustion engine is not used, a hybrid electric vehicle behaves like an all-electric car.
Pros and cons of HEVs and PHEVs
Pros:
- Reduction of fuel consumption and thus lower operational costs
- Local emission-free driving
- High torque via the electric motor when starting and accelerating
- Less noise emissions during purely electric drive
Cons:
- More expensive than a comparable vehicle with a combustion engine only
- More complex propulsion system, therefore potentially higher maintenance costs
- Higher vehicle weight due to traction battery and additional components
- Smaller boot space for some vehicles, as space is needed for the high-voltage battery
The all-electric future: Battery Electric Vehicles and hydrogen-powered cars
Today, all signs point to electric drive systems as the propulsion system of the future. However, it is not yet clear which energy storage system will prevail. The development of lithium-ion battery technology and fuel cells is currently highly dynamic, so that enormous progress is currently being made in both areas. In addition to technical innovations, both areas are concerned with scalability and cost reduction in production.
The focus of technical developments in traction batteries continues to be an increase in energy density. The aim is to make the batteries smaller and lighter while maintaining the same capacity, i.e., the same driving distance of the vehicle. At the same time, efforts are being made to optimise the chemical composition of the battery cells to reduce the percentage of critical metals, such as cobalt to a minimum.
Even though there are already some hydrogen-powered cars on the market, the mass production of fuel cell drives is still further away than that of lithium-ion batteries. Current development is focused on reducing the need for platinum in the fuel cell to significantly lower costs. Further progress is being made in making the fuel cell membrane more robust and durable.
Apart from the energy storage system, the powertrain architecture of Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs) is largely comparable.
Design of the BEV with an electric motor and a high-voltage traction battery.
1. 12 Volt Battery
2. DC/DC Converter
3. Large high-voltage LiIon battery
4. AC/DC Converter
5. High-voltage traction motor
6. Electrical power source (charging station/wall box)
The FCEV uses a hydrogen tank, a fuel cell, and a small Li-ion battery as intermediate storage to power the electric drive.
1. 12 Volt Battery
2. DC/DC Converter
3. Large high-voltage LiIon battery
4. AC/DC Converter
5. High-voltage traction motor
6. Fuel cell
7. Hydrogen tank
Pros and Cons of BEVs and FCEVs
Pros:
- Less complex drivetrain than HEVs, thus potentially lower maintenance costs
- High torque and good driving dynamics through pure electric drive
- Local emission-free driving
- With BEV: Low operating costs in connection with a private photovoltaic system
Cons:
- Less extensive network of hydrogen fuelling stations and charging stations compared to conventional petrol stations
- Long "refuelling" for BEVs
- Many models only partially suitable for long-distance use
- Without subsidies, more expensive than comparable conventional vehicles with combustion engines
The low-voltage system in every Electric Vehicle
Historically, the 12V battery is often referred to as a starter battery. In a conventional vehicle with a combustion engine, we are used to the motor being cranked by an electrically operated starter. But even purely electric vehicles still need a 12V battery to function. And technically speaking, one could still call it a starter battery for "electric cars". When the vehicle is parked, the high-voltage battery is disconnected from the electrical system for safety reasons. If the journey is to be continued, the high-voltage battery must first be started - and it is precisely this starting process that is initiated by the 12V battery.
The vehicle's 12V network supplies comfort functions, control units, sensors and actuators.
To still call it a starter battery in modern vehicles, regardless of whether they have an internal combustion engine or are "fully electric", does not do justice to the tasks of the 12V battery. In this article, we have detailed the tasks that the battery handles in addition to the actual starting of the vehicle.
Conclusion
The automotive future is electric. Currently, different concepts are available simultaneously each with their own advantages and disadvantages. The customer is thus spoilt for choice when it comes to choosing the most suitable concept for his or her individual needs. Hybrid concepts combine the best of both worlds. On the one hand, they offer long range thanks to very efficient combustion engines, the possibility of local emission-free driving and high torque right from the start because of the additional electric drive. On the other hand, the already complex drive and exhaust treatment system becomes even more complex due to the electric components.
Most electric cars today rely on a large Li-ion high-voltage battery for energy storage. Long ranges are still limited to premium vehicles with large traction batteries. However, current research aims to further improve the range and to dispense with critical metals. Technical advances and more efficient large-scale production will also be able to further reduce the cost of the battery, so that "electric cars" will become competitive in other vehicle segments. The use of hydrogen as an energy storage medium is another promising approach for the future of the automobile and could help to overcome the two major drawbacks of today's battery electric cars: the heavy traction battery and the long charging times.
Which concept will prevail in the future cannot be predicted with certainty at this point. It is clear, however, that apart from the actual drive concept, there are no further differences between the vehicles. What they all have in common is the electronics installed in the vehicle for comfort and safety systems, which continue to be based on the established 12V electrical system and are supported by a 12V battery.
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Battery Service & Testing

How to use hand-held battery tester correctly

The right parameters are the key

Obviously, as a user I can only expect a correct test result if I have made the right settings beforehand. Our analysis of about 300,000 tests has shown that in about 1/3 of all tests the user's entries were not correct and therefore the test result is not reliable. So let's first talk about which parameters are important and decisive for a professional battery test. Let's take a closer look at the battery label to find the information we need.

1) Technology

The design of an AGM battery differs in detail quite clearly from a flooded battery. But also between a conventional starter battery (SLI) and an enhanced flooded battery (EFB) there are some differences to improve the cycle life of the EFB.

A closer look inside the battery helps to understand how the battery technology influences the internal structure of the battery.

Battery construction EFB

Battery construction AGM

Examples of differences in design between the battery technologies

	AGM	EFB	SLI
Positive Grid	Powerframe	Powerframe	Powerframe
Negative Grid	Con-Cast	Expanded	Expanded
Mass Recipe	Most advanced for ST/ST	Improved for ST/ST	Designed for Starting Applications
Scrim on pos. Plate	No	Yes	No
Separator	Glass Mat	Polyester	Polyester
Acid System	Absorbed	Flooded	Flooded
Cell Compression	High	Medium	Low

To understand how the internal structure of the battery influences the test result, it helps to understand how a handheld battery tester works. In very simplified form, a test works by sending a short energy pulse into the battery and then analysing the battery's response to this short pulse to determine its state of health (SOH) and to calculate the remaining starting power.

Thus, no real cold cranking current is measured, but an algorithm is used to derive the battery condition. In order for the tester's algorithm to interpret the battery's response correctly, it is therefore essential that the correct technology is selected before the test..

2) The Test-Standard

A lab test like we perform to prove the cold cranking performance is fundamentally different from the test procedure of a handheld battery tester. The small "(EN)" on the label indicates that we perform the cold start test as defined in the European battery standard EN50342-1

To do this, the battery is first cooled down to a temperature of -18°C in a climate chamber for at least 24 hours. This is already a clear difference to the test in the workshop.

The second major difference is the test procedure itself. In the laboratory test, a real cold start is simulated and it is checked whether the battery can actually deliver the current indicated on the label. Several hundred amps flow for over a minute.

Nowadays, EN 50342 is the standard for car batteries in Europe, but in other regions of the world there are different test procedures. This is especially interesting for the daily workshop routine if you have vehicles from Asian or US-American manufacturers in your workshop and want to change the batteries there. If the CCA rating on the installed batteries was determined according to JIS or SAE standards, the numerical value is not comparable with a value according to EN. In this case you have to select the valid standard in the tester, otherwise you will get wrong results..

To illustrate how different the numerical values can only be due to a different test procedure with identical batteries, let's compare the cold start values of an OPTIMA battery - also a CLARIOS brand and also a battery in AGM technology. Once tested to EN and once tested to SAE. Remember, it's the same battery.

The difference between "DIN" and "EN"

Most testers offer both "EN" and "DIN" when selecting the test standard. As already described, EN 50342 is the leading standard in Europe today. However, the standardisation process means that the European Standards EN are becoming national standards, so that an EN 50342 becomes a DIN EN 50342.So why do most testers offer both and does it actually not mean the same thing?

To make a long story short: In the context of the battery tester, the selection items "DIN" and "EN" describe two different test procedures.

The selection point "DIN" refers to the (no longer common) procedure according to DIN 72311 or DIN 43539-2 for determining the cold start current.

The selection point "EN" refers to the test procedure according to EN 50342-1 which is common in Europe today.

The pure numerical value of a test according to "DIN" is only about 60% of the numerical value of a test according to "EN". In order to obtain a correct test result, it is therefore very important to select the correct test standard.

3)Cold Cranking Amps

The third important entry refers to the actual cold cranking current of the battery. Here it is obviously also important to enter the correct value to get a reliable test result.

With the correct entry of the three parameters for technology, test standard and cold cranking amps, the most important requirements for a correct battery test are given and your customer will get a reliable report about the condition of his battery.

A few more tips for the accurate battery test

In order to get reliable results, it’s crucial to use a battery tester that is able to differentiate between AGM, EFB and SLI batteries.

The capabilities of battery testers are limited. As there are so many different batteries from different manufacturers and with different designs and levels of quality in the market the algorithm of the tester can’t be 100% accurate. On the other hand, the manufacturers of battery testers continually develop and improve the algorithms and devices, therefore it’s recommended to use a tester with the latest technology in order to get the best and most reliable results.

Battery testers are designed to test used and cycled batteries therefore they should not be used to test new batteries e.g. for incoming inspections.

Always connect the battery tester directly to the battery terminals, do not use any other connection or the jumpstart connections. The electrical resistance or capacity of the vehicles system might influence electrical measurements performed by the tester and therefore would lead to biased readings and finally unreliable results.

Conclusion

A test result is only as good as the data the tester is fed with. That is why it is so important to set the battery technology, test standard and CCA rating correctly beforehand. Only then the tester can deliver a reliable result. The test method is fundamentally different from the laboratory tests that we as a manufacturer use in the development and validation of the battery. Therefore a battery test of a handheld tester can never be 100% accurate. Therefore it is even more important that you as a user in the workshop work precisely to get a solid test result.

- Battery Basics
How summer heat affects battery
The automobile clubs drive most of the battery-related services during the first frost and during the first cold winter days. You get into the car, turn the ignition key and then nothing happens for a while. Diagnosis: Battery flat. The diagnosis is correct in the vast majority of cases. However, you should know that it was not the first cold night that knocked the battery out, but mainly the hot summers before.
This is why a battery ages
When a battery reaches the end of its service life, it is a combination of various degrees of wear and aging. Wear and tear and calendrical aging are two different effects which can be explained very vividly by looking at car tyres.
Wear occurs when a vehicle is on the road. The driving style, i.e. the way the tyre is used, also has an influence on wear. Calendar aging, on the other hand, also occurs when the vehicle is not moved or the tyre is simply in stock. Here too, the material becomes brittle at some point and the tyre ages.
Just as the driving style influences wear, the external environmental conditions influence calendar ageing.
For a tire this is quite obvious. What this means for the battery will be briefly explained in the following.
Wear and tear of the battery:
Wear is caused by the use of the battery. If the battery is used frequently and extensively, it will wear out faster than a battery that is used infrequently and rarely.
Against the common assumption, it is not so much the number of engine starts that causes the battery to wear out, it is rather the number of charge and discharge cycles (Cycle Life) and the depth of these cycles (Depth of Discharge).
Wear and tear can be countered with the right battery technology. For example, if your customer has a vehicle with start-stop function, an AGM or EFB technology is certainly required. A conventional SLI battery is not designed for these applications and therefore wears out quite quickly.
Calendrical aging of the battery:
For a battery in a classic car, which is rarely used and is parked most of the time, wear and tear is usually not a great deal. In this case, the effect of calendrical aging is more likely to become apparent.
In order to explain the effects of calendrical aging, we would have to delve into the depths of the chemistry of the lead-acid battery here. But that would be taking things much too far at this point. That is why we limit this topic to one important factor: temperature. The chemical processes in the battery are strongly dependent on temperature.
As a rule of thumb you can say that the chemical reactivity doubles for every 10 Kelvin temperature increase. This leads to an exponential increase in reactivity. In fact, this effect is used to speed up laboratory tests by performing them at high temperatures. Not only in our battery lab, but actually with all suppliers and OEMs.
And here we come back to the beginning of this article, namely that the high temperatures in summer accelerate the calendrical aging and damage the battery.
Grid corrosion shortens battery life
The grid inside of the battery fulfils two essential functions for the proper operation of the battery. Firstly, it conducts the current flow from the plate surface to the plate connectors. And second, the plate provides the carrying structure for the active mass of the plate.
One of the most important aspects when it comes to temperature induced ageing is the so-called grid corrosion. Just like rust in body panels, grid corrosion also leads to decomposition of the lead alloy.
The illustrations below show original pictures of grids from a field test conducted by our US colleagues in Las Vegas. The climate in Las Vegas is a desert climate, with long, hot summers and thus ideally suited for a field test aimed at aging.

These pictures show very clearly what grid corrosion is all about and also why our VARTA PowerFrame grid is one of the key factors for long battery life.
The grid has two tasks, as mentioned above. It facilitates current conduction within the electrode and forms the mechanical skeleton for the active mass. That both are getting worse and worse with increasing grid corrosion is very evident.
Grid corrosion shortens battery life
We know now that it is the hot temperatures in summer that causes damage to the battery. Nevertheless, the statistics show very clearly that most battery failures occur in winter. How is this related? Also in this case the temperature is again very important.
As already touched on the subject of aging, the reactivity of the chemistry inside the battery strongly depends on the temperature. If we read the curve (link auf das Bild “graph influence of temperature.png” weiter oben im Artikel einfügen) the other way round, we see that the lower the temperature, the slower the chemistry inside the battery becomes. This means that on a winter day, the battery cannot give the same performance as on a warm summer day. And so it is possible that the car still starts smoothly at 20°C, but nothing happens at 0°C.
“Batteries die in summer, but it's only in winter that we realize we've bet on a dead horse.”
U. Germann – CLARIOS Technical Training Manager
We test that your customers stay on the road
As you know, with VARTA you get "The Original", meaning batteries in OEM quality. As a partner to OEMs, we are constantly developing and testing our batteries to ensure that we always offer the best product. The tests are not limited to laboratory tests, but we also regularly accompany field tests. Only in this way can we test our batteries in "real life" and in interaction with the complete vehicle electrical system.
Just recently, we completed a 12-month field test with one of our OEM customers. Similar to our PowerFrame test in Las Vegas, we went into the desert and came to Dubai.
In this test we equipped a taxi fleet with different batteries. Since a liter of gasoline costs only about 40 cents in Dubai, Start-Stop does not yet play a major role there. However, the hot climate and the excessive operation of the taxis causes the batteries to fail after only a few months. In a nutshell, the ideal test conditions for a field test.
Since the vehicles had no Start-Stop function on board, all vehicles were equipped with conventional SLI batteries from different manufacturers. For comparison, we have equipped a number of vehicles with VARTA AGM to show that the AGM technology also offers many advantages outside Start-Stop.

A total of 60 identical vehicles were equipped with the different batteries and data loggers. The result: Without exception, all SLI batteries failed after about 5-6 months. The comparison fleet equipped with AGM batteries remained mobile until the end of the test without any battery replacement.
Test key facts
Vehicle usage statistic
- 19 hours average time of driving per day
- 14,000 km driven per month
- 300 engine cranks per month
Battery usage statistic
- In 80% of operation the battery temperature was above 60°C. Maximum temperature was up to 75°C
- All returned AGM batteries had good remaining capacity of more than 75% of the initial value.
“This test conducted in close cooperation with one of our OE partners shows once again how superior modern AGM technology is when it comes to battery life and performance.”
M. Hoh – CLARIOS Senior Manager Vehicle Expertise
Conclusion
After reading this article, we now know that it is the hot temperatures in summer that causes damage to the battery.
When a battery reaches the end of its service life, it is a combination of various degrees of wear and aging.
Wear is caused by the use of the battery. If the battery is used frequently and extensively, it will wear out faster than a battery that is used infrequently and rarely.
Calendrical ageing is very much influenced by temperature, since the chemical effects, including unwanted side effects, are strongly dependent on temperature. One of the most important aspects when it comes to temperature induced ageing is the so-called grid corrosion which leads to decomposition of the lead alloy.
As the grid has two tasks, first to facilitate current conduction within the plate and second being the mechanical skeleton for the active mass. Both are getting worse with increasing grid corrosion. Our field tests under hot climate conditions have once again proven that AGM technology has been proven to give you peace of mind, whether in a vehicle with or without a start-stop function.
Batteries die in summer, but only in winter we realize that the battery has its best days past. Therefore we recommend to test every battery when a vehicle comes to your workshop. In this way you can inform your customers at an early stage about an upcoming battery failure and recommend a preventive replacement.
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- Battery Technology
The temperature's effect on batteries

What happens to the battery during summer?
It is an experience that most drivers have had: They get into their car, turn the key and nothing happens. Diagnosis: a flat battery. But contrary to popular belief, it is not the cold that stopped the battery from working, it was the hot summer temperatures over the previous years.
Main causes of battery failures
Battery failure has two main causes: wear and tear and the ageing process. Wear and tear is easy to understand when looking at car tyres: the more you drive and the harder your driving style is, the faster the wear and tear. This is similar with the battery: The more often and the deeper car batteries are discharged, and the more electric consumers drain the battery, the higher the wear and tear. Also, if you only use your car rarely or mostly for short distances, the alternator cannot fully charge the battery, while electrical consumers continue to discharge it.
This can be countered with the right battery technology. For example, if you have a vehicle with start-stop function, an AGM or EFB technology is definitely required. A conventional SLI (Starter, Lights, Ignition) battery is not designed for these applications and therefore wear out quite quickly.
The power of an AGM battery can also benefit cars without a start-stop system: AGM technology offers higher power reserves, from which conventional vehicles without start-stop benefit in the form of longer battery life. An AGM battery can also cope with extreme outside temperatures whereas a conventional starter battery reacts to extreme cold and heat with a rapid drop in capacity and discharges more quickly. This was shown in a field study in Dubai, where vehicles with a start-stop system and equipped with conventional batteries all failed after 5 to 6 months while a comparison fleet equipped with AGM batteries remained mobile until the end of the test after 12 months.
It is not possible to make blanket statements about service life and the ageing process, as service life depends on factors such as battery type, ambient temperature, number of cycles, depth of discharge or frequency of use. Nevertheless, wear and tear ultimately affects the ageing process and thus the service life of the battery.
Summer heat furthers the ageing process
Drivers believe that the cold harms a battery, but it is actually heat which causes failure. An outside temperature of +20 °C is optimal for a car battery. But in the summer, the temperature frequently climbs to above +30 °C. High temperatures lead to self-discharge of the battery, which causes the battery to age. This process goes unnoticed in summer and autumn, but when the engine needs more energy to start in winter, difficulties often occur.
As a rule of thumb, the chemical reactivity doubles for every 10 °C of temperature increase. This causes an exponential rise in chemical reactivity and therefore more damaging factors such as grid corrosion. Just like rust in body panels, grid corrosion also leads to decomposition of the lead alloy inside the battery. As the grid facilitates current conduction within the electrode and forms the mechanical skeleton for the active mass, these two tasks of the grid are performed increasingly poorly which is why high temperatures in summer accelerate ageing and damage the battery.
Why most battery changes are in winter
We have learned that summer heat causes damage to the battery and that higher temperatures increase the level of chemical reaction. This is true for temperatures above 20 °C. If temperatures drop below 20 °C, the chemistry inside the battery slows down. Taking 20 °C as optimum, the chemical reaction at 10 °C drops to 50% and at freezing point it is as low as 25%. This means that the performance of the battery can be perfect in the summer at 20 °C, while in the winter nothing happens at 0 °C and the battery needs to be replaced.
Be prepared for the winter – have your battery checked
Battery tests help to detect battery failures in advance. Ideally drivers should therefore have their batteries checked at a workshop at least once a year before winter. This ensures your mobility and protects you from additional costs and unexpected breakdowns. After all, nothing causes more trouble than a battery that still provides enough power for the lights but is too weak to start the engine.

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- Workshop Knowledge
The battery that is most trusted in

The battery brand that drivers trust the most
Car manufacturers always choose components that best suit their vehicles. That’s why 7 out of 10 new vehicles with start-stop technology are equipped with a VARTA^® AGM battery. And that is no coincidence. Because VARTA^® AGM-batteries were developed in close cooperation with leading manufacturers. They offer longer life, are less susceptible to corrosion, have lower operating costs and make VARTA^® the automotive industry’s number one battery supplier.
User choice.
And this is now also confirmed by motorists. A major survey by the leading automotive magazine “Auto Bild” has determined which battery manufacturers offer motorists the best quality. More than 40,000 readers named their favorites and VARTA^® was the most trusted car battery brand in Germany.
The benchmark for advanced battery technology.
VARTA^® Automotive batteries are manufactured in Germany in the world’s largest AGM production facility to the highest manufacturing standards and have been developed to ensure optimum performance and service life for every type of vehicle. Whether standard vehicles, extensively equipped cars with start-stop systems or electric vehicles – VARTA^® has the right technology for every energy requirement. When you choose a car battery from VARTA^®, you can be sure that you are getting reliable precision technology with first-class manufacturing quality. 98% of all lead-acid batteries are collected and successfully recycled at the end of their service life, making the classic 12V battery the most recycled product in the world.
Number one for a reason.
VARTA^® Autmotive batteries are backed by Clarios, a global leader in advanced energy storage solutions. Its portfolio of constantly evolving battery technologies offers an optimal energy solution for virtually any type of vehicle. More than 16,000 employees work in development, production and sales for technologies that offer a uniquely future-proof performance level and guarantee reliability, safety and comfort in everyday life.
Check your battery in time and regularly.
Because the battery is the heart of every vehicle. If it fails, nothing works anymore. And unfortunately, this happens quite often: According to ADAC breakdown statistics, more than 43% of all car breakdowns are due to the battery. One of the reasons for this is that modern cars are equipped with more and more comfort and assistance systems that are heavily dependent on the battery.
Regular battery checks are therefore enormously important. Are you looking for a VARTA^® Partner who offers a battery test? With the workshop search on our website, you can find your nearest battery expert in no time at all.

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- Battery Technology
Powering science with AGM batteries

How an AGM battery makes remote science experiments possible
When it comes to research projects in remote locations, scientists must face several challenges: How do you cope with possibly hazardous weather conditions? How do you power all the equipment with the next electrical out being thousands of miles away? And finally: How do you handle all this logistically? Questions, which Dr. Ulrich Münzer has the answers to. The Munich scientist has been using VARTA batteries since the 70s in his research work in Egypt and Iceland. That’s why he trusts in the quality of VARTA products.
Now Dr. Münzer is taking part in a project in the summit of the Hochvogel mountain in the Allgäu Alps. A five-metre-wide and 30-metre-long crack grows by a few millimetres every month and heralds the collapse of the entire side of the peak. Geoscientists are trying to predict when this rockfall will happen. Many of the adjacent rock formations that used to be held together by ice are now gradually losing their icy “cement” and becoming unstable. But it is difficult to predict when a rockslide will actually break loose.
Remote sensing of climate‐induced natural hazards
AlpSenseRely is a three-year reliability and potential study on remote sensing-based early warning systems for natural hazards in particularly climate-sensitive alpine areas. It makes an important contribution to the risk and cost reduction of climate-related natural hazards. AlpSenseRely aims at anticipation and real-time warning of critical objects and processes in the impact environment of infrastructure. In 2018 the preliminary study AlpSenseBench operated as a benchmark to systematically explore the capacity of high-resolution observation and monitoring.
Michael Krautblatter and Johannes Leinauer (TUM) and their team have been active on the Hochvogel in the Allgäu region since summer 2018. They are equipping the summit with sensitive measuring instruments to study slope movements. They use a unique innovative combination of measuring techniques with optical, radar and infrared sensor technologies, operating space-borne, air-borne, and terrestrial.
The project is a joint venture between the Technical University of Munich (TUM), the Ludwig-Maximilians-University Munich (LMU), the Bavarian Academy of Sciences and Humanities and 3D RealityMaps GmbH. Under the supervision of Dr. Juilson Jubanski, the latter developed high resolution 3D images, taken by a special drone.
AGM Battery technology to rely on – no matter where
To ensure a reliable power supply on the mountain, the team uses VARTA ProMotive AGM truck batteries which were flown up to the Vernagtferner (3450 m) and Hochvogel (2600 m) sites via helicopter. With a weight of 61kg per battery, certainly not an easy task. All the equipment including webcams, measuring devices, rain gauges, modems and data loggers draws power from the AGM batteries which are charged by solar panels. Apart from the many electric consumers, the biggest challenge is the climate: -15 °C in winter and up to 35 degrees in the summer put a lot of stress on the batteries.
The VARTA ProMotive AGM is the battery of choice when it comes to delivering the highest performance – not only to fleets on the road but also in harsh environments. It provides 6 times longer cycle life compared to conventional (SLI) batteries. The Cycle Life is a crucial performance indicator in energy demanding applications. It defines how many times a battery can be discharged and recharged before it reaches its end of life.
The VARTA ProMotive AGM has the capability of 80% depth of discharge (DoD) without being damaged. Compared to that, the recommended DoD of an SLI battery is 20% maximum. In combination with the bound electrolyte, the enhanced fixations, and the durable injection molded case the ProMotive AGM is an extremely powerful and robust build.
If you would like to read more about how the VARTA ProMotive AGM benefits heavy commercial vehicles all over Europe, you can find a number of success stories in the new VARTA Partner Portal.

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- Battery Basics
Get the best out of your battery

How to extend the life of your battery
When it comes to charging a battery outside of the vehicle or application, the right treatment can make all the difference. To get the most out of your VARTA^® battery, there are a few tricks to keep in mind.
1. Disconnect the cables
This is very important: Disconnect the cable leading to the negative terminal first! This will prevent a short circuit between the positive terminal and ground. Then proceed to disconnect the red cable from the positive terminal.
2. Check the battery’s state
If you are dealing with a lead-acid battery that is not considered maintenance-free, please visit a professional workshop. Do not check the electrolyte level by yourself. Maintenance-free batteries like VARTA^® AGM, EFB and SLI typically do not require any acid level checking. Just clean any dirt off the vent pipes.
3. Start charging
If you need to remove the battery from the car to charge it, it is important to keep it in an upright position when handling it. If the battery can remain in the vehicle, be sure to switch off all electrical consumers before connecting the charger. Also be mindful that the charger is connected to the battery before the mains. Start by fastening the red cable to the positive terminal of the battery then connect the black cable to the negative terminal.
4. Stop charging
When the charger indicates a fully charged battery, first switch off the charger before removing the cables from the battery. Back in the vehicle, the red cable must first be connected to the positive terminal followed by the black cable connected to the negative terminal.
Vehicles with start-stop
Charging an AGM or EFB battery follows the same principles. However, it is important to use the right device and charging method that is suitable for the technology. For example, some chargers have a special mode for charging gel batteries that is not compatible with AGM technology. In any case, please refer to the information in the operating instructions.
The right charging time.
Charging a battery takes time. Typically, 12 to 24 hours is a sufficient charging time. For example, a common 70Ah battery needs approx. 15 hours to fully charge with a 5A charger. A brief two-hour charge will only get the battery to 15%. That will suffice for a quick boost but will not fully charge the battery. To calculate the total charge time for a battery, take the Ah-rating of the battery and divide by the charger rating (A). Then add about 10% for the extra time to totally top off the battery
The perils of float charging.
When using an automatic charger, it will indicate when the battery is fully charged. Most automatic chargers also feature a mode called float charge. Float charge means to keep charging a battery after it is fully charged to compensate for self-discharge the battery is exposed to. The lead acid battery is an electrochemical system, which is never switched off entirely, so some side reactions cause the self-discharge.
The float charge mode should only be used for short periods of time, as it was originally intended to compensate for a battery’s natural self-discharge. Some chargers might charge an amount of Ahs during float charge, which is more than what is needed to compensate self-discharge. The reactions inside a lead acid battery may lead to an early failure.
To ensure a long battery life, avoid extensive float charging. If possible, limit the float charge time by corresponding charger settings. If a battery is not used for a longer time, prefer a full charge before storing it and check its OCV (Open circuit Voltage) regularly (at least every 3 months). Recharge if necessary (latest at 12.4V).
If you bear these few simple things in mind, you will get the most out of your battery and can be sure that it will support you on all your journeys for a long time.

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- Battery Service & Testing
Check the battery after long standstil

Irregular vehicle use has long term effects on the battery
Having your battery checked is now more important than ever because many cars have not been used as regularly as they normally would have, over the last year. Most private vehicles clocked up fewer miles due to COVID-19 lockdown restrictions and a drop in commuter journeys. As a result, batteries faced major challenges last year. With continued restrictions in 2021 this looks set to continue for now.
When in addition to this we have warm weather outside it accelerates the degradation of the battery’s health, and so there are lots of cars out there with a weak battery.
The effects of a long standstill
Many cars have been stood still for months on end; therefore, the alternator has not had chance to recharge the battery. This along with a hot spring / summer and the cold winter have led to many batteries failing and leaving people stranded, particularly over the winter months where cold weather means the battery has to work harder to start the engine.
Today’s increased demands on the battery
This is also reflected in the latest ADAC roadside assistance statistics: Nearly 46% of all car breakdowns are caused by the battery in poor state of health. This underlines that batteries face greater demands than ever before, as they have to serve increasingly complex and power-hungry car electronics. Whereas Start-Stop systems, digital dashboards, inbuilt screens and parking cameras used to be limited to high-end vehicles, they are now commonplace on even entry-level models, all placing additional strain on the battery.
Many drivers are also plugging in their mobile devices to charge them whilst on-the-move, again drawing power from the vehicle. Therefore, it’s paramount to ensure the battery is in a condition to support all the comfort and safety features; it’s the heart of the car.
It’s been a challenging year for all of us and also for batteries. To avoid further troubles, have your battery tested. For more information on where to test your battery, find your nearest VARTA^® partner workshop.

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- Battery Service & Testing
Avoid Battery Failure
Car batteries: After the summer heat comes the deadly freeze
When temperatures start to fall and winter is just around the corner, it is time to take your car to the workshop and get it ready for the cold season. Although while changing tyres, testing lights and refilling fluids are standard procedures, the battery is often overlooked – unjustly, because the continuous operation of windshield heaters, rear window defrosters, headlights and wipers are a constant strain. As the latest ADAC statistics show, approximately 43% of all car breakdowns are caused by batteries. So will your battery make it through the winter? The only way to find out is to have it checked by a workshop.
- 40% of car breakdowns are caused by battery failure
- Heat shortens the life-span of car batteries
- Battery replacement should be carried out by a workshop
Batteries age in summer and fail in winter
Dr. Christian Rosenkranz, head of the development department at Clarios.
Winter is usually a time when cold weather proves too harsh for a weak battery to survive – especially if it was preceded by an extraordinary long and hot summer as this year was. Heat dramatically shortens the life-span of a battery, so by the time winter comes, older batteries are close to their limit. “Many drivers think that cold weather does damage to the battery, but it is the heat that is the start of its downfall,” explains Dr. Christian Rosenkranz, Vice President Engineering at Clarios. An outside temperature of +20°C is optimal for a car battery. This year the temperature often climbed over +30°C.
High temperatures lead to self-discharge of the battery and cause its electrochemical parts to age more quickly. “These effects may not cause the battery to fail immediately, but they can jump-start the deterioration,” says Rosenkranz. Whilst this development remains unnoticed throughout summer and autumn, the problems start to show in winter, when more energy is needed to start the engine. For this reason, the battery should be checked regularly throughout the whole year.
Apart from extreme temperatures in summer and winter, there are many other reasons that can cause battery failures. If the car is used infrequently or only for short distances, the alternator cannot fully charge the battery, while electrical consumers as the rear window and seat heating contribute to further battery discharge. Long downtimes should be avoided if possible, because in many modern cars the battery has to supply energy even when the engine is switched off: Systems such as alarms, door locks, keyless-go functions and navigation systems need energy even when the car is parked. Especially in winter, drivers should therefore try to make a longer journey at least once per month for the battery to be fully re-charged.
The battery is part of a complex electrical system
As the battery ages, its performance decreases since corrosion and sulfation prevent it from fully charging. If a check reveals that the battery should be replaced, this should be handled by a workshop. In today’s cars, the role of the battery has changed: it does not only provide energy for the ignition and to start the vehicle, but is part of a complex electrical system, powering a wide range of comfort and fuel-saving functions such as air conditioning, seat heaters and Start-Stop systems. Furthermore, the battery is no longer easily accessible under the bonnet, but may be installed in the boot or under a seat. Because of this, special tools and expertise are needed to replace batteries in modern cars. In order to ensure a problem-free and safe replacement, this task should be carried out by a specialist.
“Battery testing helps to indicate upcoming failure. Therefore, drivers should have their batteries checked by workshops at least once a year before winter,” says Rosenkranz. “This keeps them on the road and protects them from additional costs and hassle. Nothing is more annoying than a battery that is still strong enough to turn on the lights, but too weak to spin the starter.”
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- Workshop Knowledge
VARTA Partner Portal Data Update
The VARTA^® Application Database now covers 99.6 percent of all car models in Europe
- Enlarged service offering for workshops and consumers
- 7,176 additional car models
- VARTA^® Partner Portal is preparing workshops for new battery service situations.
The European car fleet comprises more than 40,000 models, which means that not even experts are able to identify the right battery for every single one of them. This is where the VARTA^® Partner Portal by Clarios comes in and provides assistance with finding the right fit. VARTA^® Automotive has now updated its reference application database with an additional 7,176 vehicle models from 165 brands, representing 19.8 million additional vehicles on Europe´s roads. The database therefore covers 94 percent of the models in the European market and no fewer than 99.6 percent or 381 million of the registered vehicles. Customers and workshops can now search for 38,000 car models and their batteries in linked customer portals on the VARTA Automotive website and the VARTA Partner Portal.
The VARTA^® Partner Portal offers four modules to prepare workshops for new battery service situations, too. That includes the growing number of start-stop vehicles. Not only are vehicle electronics increasing in complexity as a result, but battery testing and replacement are also becoming more difficult. Battery service is now a complex task for workshop mechanics, who need up to 28 steps to change a battery. Consequently, service times for a battery change have increased significantly – in part, as well, because they are often installed in locations that are difficult to access.
Four modules for all the key information
Free, unlimited access to the VARTA^® Partner Portal is quickly and easily available for every workshop employee with any internet-enabled device after a one-off registration. It provides workshop employees with various options to immediately obtain all the key information for replacing the battery:
The BATTERY SELECTION module provides the exact-fit battery recommendation and can find a specific battery by part number through the Battery Search Code. It suggests alternatives for an enhanced performance and covers nearly all start-stop car models.
With the BATTERY POSITION module, workshop employees can find the battery right away. The Partner Portal shows a detailed image where the battery is located in the selected vehicle. Details, for example the fastest way to access the battery, can be called up with a click.
The step-by-step FITTING INSTRUCTIONS show the estimated service time and help to change a battery more efficient and accurately. They also make the battery fitting process easier for start-stop vehicles and indicate whether you have to connect to the battery management system.
The BATTERY KNOWLEDGE section is a repository of know-how. It explains, for instance, the changed role of the battery, the importance of using the right battery technology for start-stop vehicles and the special factors that have to be taken into account when testing batteries in start-stop vehicles.
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- Battery Technology
Unique auxiliary battery
Many modern vehicles with combustion engines now come with a normal 12 volt starter battery and an auxiliary battery. This configuration is known as a “dual-battery system”. In particular, the high class models of the leading original equipment manufacturers require a compact, powerful auxiliary battery. The VARTA^® Silver Dynamic Auxiliary AUX 1 was especially developed to meet the OE requirements of high power demand and compact dimensions.
The unique battery solution from Clarios
Since 2018 the AUX1 has been part of the VARTA^® Silver Dynamic Auxiliary product range. It is equipped with the patented PowerFrame^® grid technology which in comparison with other grid designs, provides up to 66% longer service life, excellent starting power and up to 70% increase in current flow. Clarios is the only manufacturer on the global market which offers this type of battery – both as an OEM component as well as an original spare part.
Features:
- Increases the length of the start-stop function for start-stop systems
- Especially suitable for vehicles with a large number of electrical consumers
- Patented PowerFrame^® grid technology
- Latest silver-calcium technology
- Low self-discharge
- Supports comfort functions during engine start
- Reliable starting power even at temperatures below freezing point
- Meets all OEM standards
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- Start-stop
Deactivating start-stop

Is a regular battery sufficient if start-stop is deactivated?
Start-stop systems as we now know them, have had an eventful history. Start-stop systems as we now know them, have had an eventful history. More than 40 years ago, Toyota developers presented an electronic system to automatically stop the engine when the vehicle stopped. At the beginning of the 1980’s Volkswagen made initial attempts in this direction – in those days with a button to switch off the engine when required. The result: The Golf III Ecomatic was the first vehicle from the Wolfsburg car manufacturer to be equipped with a start stop function.
Today, start-stop is standard equipment
Nowadays, start-stop is no longer a gadget in the list of options, instead it’s standard equipment for most vehicles. The reasons for this are more stringent legal emission limits and a change in environmental awareness on the part of consumers.
New fuel saving functions support start-stop
The fuel saving systems in modern vehicles have developed much further in comparison with those in the early days. With additional functions such as recuperation (recovery of braking energy) they go far beyond simply switching off the engine at red traffic lights.
As fuel saving technologies became increasingly common for vehicle manufacturers over the years, the more intelligent they became. Among other things this has meant that the battery and energy management of the entire vehicle have become increasingly merged.
Can I install a conventional battery if I permanently deactivate the start-stop system?
As has already been said, these days switching off the engine when the vehicle is stopped is only one of many fuel saving functions.
In addition to recuperation, these also include sailing (the engine switches off while driving) and boosting (more rapid acceleration for short periods). The battery therefore also has a heavier load than in conventional vehicles, even if the start-stop function is deactivated.
Almost all modern vehicles have a dedicated battery sensor (BMS) to control the efficiency and comfort functions in the vehicle. If the battery is replaced without being correctly registered in the BMS, this can result in increased wear. Many vehicles are also equipped with a so-called self-learning battery sensor. In this case, the manufacturer assumes that the right battery technology is installed. If a conventional battery is installed, this can cause increased battery wear and ultimately premature failure.
Our tip: Decide on the right technology from the start and help the environment! The VARTA Battery Search identifies which battery is best for the particular vehicle.

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Find a trusted workshop

Do you want to rely on a car battery expert to service your vehicle? Go to our VARTA^® Partner Finder and locate a trusted workshop near you.

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Deepen your knowledge

- Battery Technology
- Truck
Construction of VARTA Promotive EFB Truck Batteries

A patented mixing element ensures that acid stratification cannot occur in our ProMotive EFB battery. Read our article now to find out exactly how this works and what advantages it brings.

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- Battery Technology
- Truck
The importance of charge acceptance of truck batteries

Batteries with high starting current (CAA) and sufficient capacity (C20) guarantee reliable fleet operation. We tell you why.

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- Battery Basics
Battery tips for the leisure season

Get ready for your journey. Discover helpful tips and tricks for your leisure battery to get the best start to the season

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Got a question?

Make use of our VARTA Battery Finder to find the battery product that fits your vehicle.
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VARTA team to provide content
VARTA team to provide content

Construction of VARTA Promotive EFB Truck Batteries

The new wet battery for trucks

Why is acid stratification a problem?

VARTA® ProMotive EFB Batteries – a revolutionary solution

Performance of VARTA® ProMotive EFB batteries repeatedly confirmed

The importance of charge acceptance of truck batteries

Modern hoteling functions need power

Charging times are reducing, but power demands are growing

Charge acceptance – a critical factor for older batteries

On the safe side with VARTA® truck batteries

Battery tips for the leisure season

Getting your leisure vehicle ready for the start of the season

Different technologies for different applications

Maintenance tips & tricks

Prior to the rest period

During the rest period

After the rest period

Sources of battery failure

Choosing the right battery for your journey

Voltage stabilization during battery exchange

What is voltage stabilization?

Recommendation for voltage stabilization

Conclusion

The right code of the BEM for Battery replacement

Different ways of battery coding

Battery coding without a tool

Vehicle with rear fog light:

Vehicle without fog light:

Conclusion

Varta® truck batteries are robust

New challenges for truck batteries

VARTA® truck batteries meet the highest requirements of the current standard.

Planning security through reliability

AGM truck batteries in detail

AGM battery technology

Innovation with precision

Teamwork for best performance

What is a charging cycle, and why are there increasingly more of them?

Fleet managers are under pressure

Trucks with hoteling function provide comfort

VARTA® – The truck battery professionals

Electric vehicles and the 12V battery

Different types of electric cars and their dependence on the 12V battery

What is an xEV?

Hybrid Electric Vehicles. The best of both worlds?

The difference between Full Hybrid and Plug-in Hybrid Vehicles

Pros and cons of HEVs and PHEVs

The all-electric future: Battery Electric Vehicles and hydrogen-powered cars

Pros and Cons of BEVs and FCEVs

The low-voltage system in every Electric Vehicle

Conclusion

How to use hand-held battery tester correctly

The right parameters are the key

Examples of differences in design between the battery technologies

A few more tips for the accurate battery test

Conclusion

How summer heat affects battery

This is why a battery ages

Wear and tear of the battery:

Calendrical aging of the battery:

Grid corrosion shortens battery life

Grid corrosion shortens battery life

We test that your customers stay on the road

Test key facts

Conclusion

The temperature's effect on batteries

What happens to the battery during summer?

Main causes of battery failures

Summer heat furthers the ageing process

Why most battery changes are in winter

Be prepared for the winter – have your battery checked

The battery that is most trusted in

The battery brand that drivers trust the most

User choice.

The benchmark for advanced battery technology.

Number one for a reason.

Check your battery in time and regularly.

Powering science with AGM batteries

How an AGM battery makes remote science experiments possible

Remote sensing of climate‐induced natural hazards

VARTA^® ProMotive EFB Batteries – a revolutionary solution

Performance of VARTA^® ProMotive EFB batteries repeatedly confirmed

On the safe side with VARTA^® truck batteries

VARTA^® truck batteries meet the highest requirements of the current standard.

VARTA^® – The truck battery professionals

The VARTA^® Application Database now covers 99.6 percent of all car models in Europe