Instructions for working with a maintenance-free battery (BMW 7 Series E32)

BMW 7 series cars are equipped with a maintenance-free battery as standard. This battery no longer requires adding distilled water as part of maintenance, but when working with such batteries, you must follow certain rules.

The lid has a ventilation hole through which the battery can "breathe". To prevent electrolyte from leaking out, the battery should not be tilted more than 45°.

To charge the battery, you can use a normal charger or a fast charger. In the latter case, the battery must be removed.

If an electronic charger is used to charge the battery, the battery can be charged in the installed and connected state. The electronics of the charger prevent voltage surges during charging.

Heavily discharged batteries should be charged only with an electronic charger. When charging from a normal charger, the initial current is too high, so the battery may be damaged or out of order.

If the electrolyte level in the battery is too low, for example, when operating the car in a hot climate, you need to add distilled water to the battery.

If the vehicle is not in use, the battery must be recharged every 6 weeks.

If the car is not used for more than 6 weeks, the battery must be removed and stored charged. The storage temperature should be from 0 to +27°C, since this is when the battery has the lowest self-discharge. After 3 months, the battery must be recharged. The battery contacts must be regularly cleaned and lubricated with protective grease.

Starting devices should only be used in exceptional cases, since in this case the battery will be exposed to very high current.