In one of the UK fora, there was quite a discussion about the 12 volt battery. I did some investigation and here is what I have found so far.
- the battery is a normal car battery, read, a lead-acid starter type battery. I assume same as i.e. Clio;
- the battery is needed to boot the car. Without it, the 400 volt system cannot be activated, which is a deadlock.
As for charging and jump-starting, this is all verboten by the manuals. With that disclaimer in place:
- you can jump-start the ZOE by connecting another isolated battery and starting the ZOE. It will start charging the empty battery immediately;
- alternatively, charge the battery with an external charger, but then always disconnect the minus pole of the ZOE first;
- jump-starting another car is possible (as it is a starter battery), but again, always disconnect the ZOE’s minus first.