So I think my 4 year old 12V is nearly dead, but the odd thing is I have had no warnings. The last couple of nights I heard the HV contactor click when I took the dog out for his late night walk. This morning I paid more attention, and noticed the contactor is clicking once/minute. I pulled the nose cone (2014) and put a voltmeter on the jumper terminals, and found some interesting behavior:
To make matters more annoying, there's no way to request mobile service to come out to replace it. "Replace 12V battery" isn't a choice in the app's service menu, so I select "something else", which apparently means "I have nothing better to do than drive 5 hours round trip to the 'local' service center" since that's all it offers...
- Voltage drops to ~12.4V, contactors close, coolant pumps come on
- Battery charges up to 14.5V in one minute; pumps shut off and contactors open
- Battery drops to 12.4V in another minute, and the cycle repeats
To make matters more annoying, there's no way to request mobile service to come out to replace it. "Replace 12V battery" isn't a choice in the app's service menu, so I select "something else", which apparently means "I have nothing better to do than drive 5 hours round trip to the 'local' service center" since that's all it offers...