The lead acid battery in our 928 needs to be fully charged to cope with the power demand of starting the 8 cylinder engine.
It takes a battery of 70+ Ah and a starting current of over 600 Amps to turn the cold engine over. This is especially important in wintertime when the battery capacity is lower than in summer, and the engine requires more force to turn due to thicker oil in the various passages and bearings. So sort of a worst case scenario.

How do we keep the battery in condition?

How to charge the battery?

Rejuvenating a bad battery?

there are several stories about this.

Bottom line:

Regards, Theo