Often the battery of the car is not under suspicion as the car can start and maintain power. So why start troubleshooting here?

It is a good idea to study the battery monitoring system strategy. Regardless of car brand, you want to make sure that the car will start and that safety systems work. On the other hand, you do not want to overcharge the battery of the car, so the battery monitoring keeps a constant eye on both charge and battery status as well as the actual consumption. The battery monitoring is particularly necessary in cars with start/stop system as several minutes of stop at a traffic light with all electrical consumers in the vehicle turned on may cause a discharge of up to 100A. Depending on car brand, the control system of battery and charge status are sophisticated, to a greater or lesser degree. It is evident that regardless of car brand, the start/stop system should be able to turn the engine off and on again or turn off certain types of electrical consumers, while the car is stationary with the engine turned off. Therefore, it is a good indicator for the state of the car battery, if the start/stop system turns the engine back on shortly after a standstill or completely deselects start/stop. Generally, this is indicated with a symbol in the car display.

It is a cause for wonder that most car brands do not store fault codes when the car battery is ready for replacement, but this is the exception rather than the rule. Fortunately, more car brands have a good battery status monitoring so that you via the diagnostic tool parameters can see values from the battery monitoring system of the car.

It is noteworthy that when fitting a new battery, it must be a battery of the same type and preferably also of same capacity. Likewise, it is important to program the new battery using a diagnostic tool in cases where the manufacturer prescribes to do so, like e.g. BMW, Audi and others.

We have noticed that more and more garages have started checking the car battery “State of Health” with a suitable battery diagnostic tool, which is a very good idea. A battery below 50% should be replaced as soon as possible. In some cars, problems regarding disconnection of electrical components or with start/stop system start already when the battery capacity is approx. 75%