Battery — Basic Information and Care (BMW 3 Series E46)

The installed 12V battery consists of six cans containing positive and negative plates that are dipped in a sulfuric acid solution. The battery's job is to generate current to start the car, ignition, and lighting, as well as for other consumers of electrical energy.

Battery Care

The following maintenance should be performed from time to time to ensure that the battery lasts longer and maintains its maximum capacity.

1. Always keep the battery and its surrounding parts clean. The surface of the battery must always be dry, otherwise surface leakage currents may occur between individual cells, causing the battery to discharge itself.

2. The electrolyte level should always be at the ring on the bottom of the filling chamber. Use distilled water to top up.

3. In cold weather, do not leave the battery uncharged, otherwise it will freeze. Weakly charged batteries freeze earlier than charged ones.