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12v Battery Charging Schedule

I haven't been able to find detailed info on the 12v battery charging on the forum, so I figured I'd ask...then commence the experiments. I'm interested in:
1 - min/max volts (or time) that trigger charging commands from the main pack
2 - any difference in behavior depending on if the car is plugged in, awake or sleeping
3 - the average power draw from onboard components (i.e. vampire loss) when the car is not plugged in and awake or sleeping

The reason I'm interested: my latest project was the permanent installation of an inverter in the frunk for some always on electronics (I have pictures from the installation if anyone is interested). It has a remote on/off control and extension cord combination that will eventually be routed to the cabin for, well, stuff of course. Ultimately, I'd like to know how much power I can draw from the 12v battery and not exceed what the main pack puts back in.

Naturally this isn't an issue while driving (or when sitting in the car), however at first glance I've noticed the voltage drops enough where the inverter will trigger a low voltage alarm after parked for a few hours at night but not during the day (even when plugged in). Hence my inkling that it has different charge schedules when awake or sleeping since I have night time energy saving mode enabled.

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