Originally Posted by Yinzer
What specifically do you mean by "tried to charge the 12 volt battery"?
Plugging the car to a charging station or adapter with a dead 12V battery will not hurt the car - it just won't charge until the 12V battery has been separately charged so it has enough voltage to turn on the control systems.
You need to get to the 12 volt battery connected a charger - or jump it from another car. As soon as the 12 volt battery is charged a bit, turn the key and the car should "turn on" and the battery will be charged the rest of the way from the traction pack and DC-DC converter. It is just like jumping an IC engine car, starting the engine, then letting the alternator charge the battery the rest of the way.
I used a small car jumper (Halo) after I opened the 12-volt battery compartment under the pass floorboard. I didn't get any indication that the electronics of the dashboard were getting power. I still don't know how it ran down the battery in the first place. The car was parked for a few days, the key was off, the car was locked, lights were possibly left on, but I don't think so. Could this be a fuse issue? IF so, how would I check that out? Thank you so much for your quick response!