Storage of the battery (Mercedes-Benz S-Class W140)

If the car has not been used for more than two months, the battery must be removed and charged. The optimal storage temperature for the battery is from 0 to +27°C. At these temperatures, self-discharge of the battery is minimal. The battery must be charged at least once every two months, otherwise it becomes unusable.

A battery that has not been used for a long time (for example, the car was not used), discharges and can also become sulfated. If such a battery is charged with a fast charger, it will not accept the charging current or, due to sulfation, will become "fully" charged too quickly. In fact, the battery is damaged.

Before you determine that the battery is damaged, you should check the following:

• Electrolyte density. If the difference between the densities in individual sections does not exceed 0.04 g/ml, then the battery must be charged with a normal charger;
• After charging, test the battery under load. If the battery characteristics are below those given in Specifications the battery is damaged;
• If the density of the electrolyte in one or two adjacent sections differs significantly (for example, in five sections 1.16 g/ml, and in the sixth 1.08 g/ml) the battery is shorted and needs to be replaced.