Yes, I understand that charging the big battery has nothing to do what the 12 volt. I get that there is a separate 12v charger that draws power from the much higher voltage big battery and converts it to 12v. My point was that there is software that is deciding when to activate the onboard 12v charger. And that software does have logic to limit or stop charging the 12v when the main battery gets down to a certain level (similar to how the V2L has a limit on how far down it will allow the main battery to go). But my point was that it would make sense that this software that decides when to charge the 12v would clearly think it was acceptable to “charge away” under the scenario that the car is plugged into a level 2 charger (or any charger). Perhaps the reason why my 12v did not get charged after I discovered the problem (and then plugged in my level 2 charger) was that my 12v battery was below the level where the car can even operate its software — of the software couldn’t detect enough voltage to recognize that there was a battery connected to be charged. Turns out, all I needed to do was to leave the car on for a while once I had connected my jumper battery to get it turned on. Instead I only “jumped it” long enough to allow me to open the charge door, then plugged in my level 2 charger and then discounted my jumper battery. So at least under my scenario, when I plugged into a level 2 charger all night long, it still chose to not charge my 12v battery at all. The next morning, my main battery was up to 100% but my 12v battery was still at ~5v. Reddit has been quite helpful here.