Battery

GENERAL INFORMATION

The installed 12 V battery consists of six cells containing positive and negative plates immersed in a sulfuric acid solution. The battery supplies current for starting, ignition and lighting, as well as for other electrical consumers.

The battery has 100% efficiency at 27°C. At –18°C, efficiency drops to 40%. To start the engine, more than twice as much energy is required than at 27°C.

Cold cranking amps (starting power) indicate the battery's ability to start the vehicle in very cold weather. It is the current in amperes that the battery delivers for 30 seconds at –18°C without voltage dropping below 7.2 volts (the minimum level required for reliable starting). The higher this value, the greater the battery's starting power. Reserve capacity indicates the time in minutes during which the battery delivers 25 amperes at 27°C, i.e. the time the battery can power all auxiliary equipment in the vehicle at night and in bad weather if the generator fails.

In winter conditions at –18°C and below, the battery will charge poorly due to increased internal resistance. On short winter trips, the energy used by the battery for starting is not restored. As a result, the battery works under stress, is constantly discharged and eventually fails.

In summer, after long trips, the engine becomes very hot and it is often difficult to restart. Such "hot starts" sometimes require as much power as cold starts, or more. This applies especially to high-compression engines with large displacement and vehicles with air conditioning. This again emphasizes the importance of selecting the correct battery for the vehicle's engine.