(November 28, 2017) When temperatures start to fall and days become shorter it is time to take your car to the workshop to prepare it for the winter. Changing to winter tires and testing lights are a matter of course for drivers. However, the car battery is often neglected, although it is under even more stress during the cold season, according to Johnson Controls, the world's largest manufacturer of automotive batteries.

For example, continuous use of the windshield heater or the air conditioning system takes a large amount of power and makes heavy demands on the battery. Especially in winter, the only way to avoid unpleasant surprises is to have the battery checked regularly by the workshop. The latest ADAC statistics show that 39% of all breakdowns are due to the battery.

Cold, ice and snow are not the only causes of strain on the battery in winter. Infrequent use or mainly short trips have an effect on the starting power of the battery.

“Drivers often have the mistaken idea that the battery does not need to supply energy when the engine is switched off,” explains Dr. Christian Rosenkranz, vice president engineering at Johnson Controls Power Solutions. “However, systems such as alarms, door locks, keyless-go functions and navigation systems also need energy when the car is parked. Windshield heaters and ventilators are in continuous use more often in winter. All this contributes to discharge of the battery.”

If the energy in the battery is not sufficient, the engine cannot be started. “Because modern batteries are maintenance-free, very few drivers have them checked by an expert“, says Rosenkranz. “Ideally, the battery should be checked at the next lighting test or tire change. If the battery needs to be changed, this should be done by a specialist”.

Modern cars are complex systems which are equipped with extensive electronics. As the “heart” of the vehicle, the battery supplies all of the electrical components with energy — from the ignition to the entertainment systems. Therefore, it is even more important that the battery functions properly under all conditions.

Special knowledge and special tools are necessary to replace the battery, for example to avoid interrupting the circuit between the battery and the onboard computer. In addition, the battery is often not easy to find and may be complicatedly installed in the trunk or in the floor space. Because of this, drivers should no longer replace the battery themselves. One false move may result in loss of data in the vehicle control units, reduced reliability of comfort functions such as seat heaters, and under certain circumstances failure of the start-stop system.”

This may require reprogramming of the electronic components, which is annoying, unnecessary, and above all expensive.

Battery failures can be due to many causes including extreme temperatures in summer and winter. An equally critical factor is if the vehicle is left standing for a long period or is only used for short trips. A short journey is usually not sufficient to fully recharge the battery.

Especially in winter, when electronics such as the rear window heater contribute to further discharge of the battery, drivers should make a longer journey at least once per month. A regular battery service should be carried out by a specialist workshop at least once per year. This service is usually free of charge and only takes a few minutes.