Check Electric System message
Zoe’s error messages to the driver are not always crystal clear. This one usually points to a failure in the 12 volt system.
There are basically two reasons why the 12 volt system can be compromised (barring real faults somewhere in the electrical system):
- failure of the 12 volt lead acid battery
- unexpected drain of the 12 volt battery (leading very very quickly to 1.)
Let me start by saying the 12 volt system feeds anything and everything that is not traction or the air conditioning compressor. For the non-Nordic version, it also feeds a few rheostats for fast wind shield defrosting. It’s all pretty beefy but still it can drain fast. Remember that all 16 computers are powered from the 12 volt system. If this bus runs bad, literally nothing will work as expected, if at all really.
Renault has the lead-acid battery replacement in their schedule set for after 3 years. This does seem pretty short indeed, but given the above, I wouldn’t dismiss the dealers suggestion for replacement flat out. If you are in doubt, at least have it tested. Lead acid batteries are loosing a notoriously amount of capacity when it gets cold, and you don’t want to get stranded with a full traction battery, but a dead 12 volt system. And if it’s dead, the computers are dead, and there will be no way to bootstrap charging it without hooking it up to an external 12 volt battery charger. Been there, read on.
Unexpected drain is pretty hard to do. The auxiliary power shuts off when the car goes in sleep mode, so even leaving on some sort of accessory through the lighter plug should shut down.
There is one scenario however, which I am pretty sure happened to me. The charger plug was not seated properly, or at least the car thought so. You can actually detect this when the motor lock retries every 2-3 seconds. This retrying continues forever and while this is going on, the car is fully awake, all computers are on, the lock motor is being fired continuously and of course no charging is happening while there is a serious load on the 12 volt system. Now one could think the 12 volt system is being replenished by the traction battery, but it isn’t. The lead acid battery was drained down to 5 volt in a few hours at which point the car went completely dead. 5 volt is devastating to a lead acid battery if not quickly charged. Luckily, I found out and diagnosed this within a few hours of it happening.
I couldn’t bootstrap the car “in situ”, because as soon as I connected my small 12 volt car charger to the battery, the car woke up, started to initialize all it’s systems and while doing so overwhelmed the charger. I removed the mass cable from the battery and charged it for an hour. After that, the battery had enough juice to pull the car through it’s initialisation. I then was able to remove the charger cable, hooked it up again and charged the car normally. The error went away after one cycle.