Batteries age in summer and die in winter

There are many prejudices and misconceptions about batteries. Most of the problems occur due to inadequate use, so some car owners change the battery once a year, and some last for five or six years.

For a start, a large number of people buy a battery with a larger capacity because they think that this way the power reserve will be higher.

This is as bad as buying a battery with a smaller capacity than the one prescribed by the manufacturer.

Alternators vary from model to model and from engine to engine, so they simply cannot charge a larger capacity battery for which they are not designed.

During operation, it is discharged and insufficiently replenished, which eventually leads to deep discharge, which is fatal for the battery.

Interestingly, a voltage of 10.5 volts is already considered a deep discharge, while a full battery has a voltage of 12.72 volts.

A voltage of 12.6 volts already means that the battery works with 85 percent of its capacity, at 12.4 V with only 65 percent and at 12.25 volts with 40 percent of capacity.

Most problems are caused by inadequate use

During deep discharge, sulfation occurs (the process of creating lead sulfate on the plates – the gray layer on the plates), and then the acid concentration decreases and corrosion occurs on the plate plates.

This is a process that leads to a drastic reduction in the number of charge and discharge cycles, which is otherwise much higher for quality batteries compared to those of lower quality.

Therefore, the logical question is how to avoid deep discharge of the battery.

In addition to purchasing adequate capacity, care should be taken to discharge during standing. If the car is not driven very often, it is necessary to check the voltage at the poles more often.

It is considered that it is necessary to recharge the battery if its voltage is below 12.4 V, and the control should be performed for at least a month.

Auto magazina batteries

If the car is not driven often, it is necessary to check the voltage regularly

Although the battery is under warranty, recharging is not prohibited if done adequately.

The recommended current charged in amperes should be 10 to 20 percent of the rated capacity (for example, a 44Ah battery should be charged with 4A to 8A current), and the battery should not be overcharged as this drastically shortens the life.

The charging interruption would have to occur at 12.75 volts when switching to the “small” charging mode. Unfortunately, such conditions are provided only by more expensive and complicated chargers.

It is important to note that the degree of self-discharge when standing also depends on the type of car. If it is a newer model with a large amount of electronic equipment, the self-discharge is higher.

You may not know it, but a large number of components are energized even when the motor is off and “pulls” a certain current.

For example, a GPS device uses a current of five milliamperes, an alarm of 10 mA, each window lifter 5 mA, a fuel injection system 5 mA, a digital clock 3 mA, an analog clock 7 mA, and a radio with a code of 3 mA.

All this refers to a situation when the engine is not running and without contact! In any case, the total quiescent current should not exceed 50 mA in cars with correct electrical installations.

It is a mistake to think that batteries do not like winter and temperatures below zero – then their capacity only decreases.

Auto magazina batteries

The recommended current charged in amperes should be 10 to 20 percent of the rated capacity

What they really don’t like are the high summer temperatures because then the water from the electrolyte evaporates, but fewer electrical consumers are used and, unlike in winter conditions, they offer less resistance.

In contrast, in winter, the starter provides greater resistance, and the batteries on diesel engines are especially affected, where the heaters work for some time after starting.

Even on the latest models, it happens that the heaters start working the moment you unlock the door!

Vibrations are another of the biggest enemies of batteries. On that occasion, it happens that the active mass falls off the plates and can very easily cause a short circuit that leads to permanent damage.

Because of all that, better quality batteries have special bags that prevent this from happening.

What is the difference between better quality and lower quality batteries? They really allow maintenance-free operation, which means there is no need to add distilled water to the electrolyte. They have specially designed labyrinth lids that allow water to return during evaporation.

Auto magazina batteries

Vibrations are another of the biggest enemies of batteries

In addition, they provide far more cold start current and more power reserve.

The cold start current is always indicated on the battery itself next to the capacity label and indicates the current that the battery must deliver for 10 seconds at a temperature of -18 degrees Celsius until the voltage per cell drops to a maximum of 1.25 volts, or total 7.5 volts for a 12 volt battery.

Capacity expressed in Ah represents the amount of electricity that can be delivered under certain conditions (for example, a capacity of 44Ah means that 2.2A can be obtained in a 20h period until the voltage drops to 10.5V).

Cold start current and capacity are completely independent categories and differ drastically in quality compared to other batteries.

After all, there is a big difference in the number of charge-discharge cycles that batteries can withstand, which is a process that happens every day during operation.

Auto magazina batteries

Cold start current and capacity are completely independent categories

Categorization in terms of models also exists within a brand. Thus, Bosch offers several battery models, which differ in terms of “density” of energy and thus the required amount of electricity in cars.

For example, the S3 model is intended for cars with smaller electronics, while the S4 and S5 store more energy in the same volume and are intended for cars with a lot of electrical equipment.

The last in the series is the S6, which is designed for the needs of cars with start-stop systems, since the starter is used in almost every movement from standstill.

One of the technologies that enables higher electrolyte levels, higher starting power and higher capacity while maintaining compact dimensions is AGM (Absorbed Glass Mat).

In essence, it is an electrolyte that is absorbed into the material that cuts on the glass wool, which also enables the use of larger surface plates.

These batteries are characterized by a higher cold start current, a large number of charge and discharge cycles and vibration resistance.

We hope that with this text you will better understand the needs of your battery because it, as an electro-chemical device, is almost a living being – it requires care and attention.

Auto magazina batteries

Source: Auto magazin by

*The article has been translated based on the content of Auto magazin by If there is any problem regarding the content, copyright, please leave a report below the article. We will try to process as quickly as possible to protect the rights of the author. Thank you very much!

*We just want readers to access information more quickly and easily with other multilingual content, instead of information only available in a certain language.

*We always respect the copyright of the content of the author and always include the original link of the source article.If the author disagrees, just leave the report below the article, the article will be edited or deleted at the request of the author. Thanks very much! Best regards!