From what you're describing, if you saw both the BAT TIE OPEN and the BAT CHARGE annunciator lights, this means that the battery disconnected from the hot battery bus due to an overheat, not a MTBF triggered failure. (I mention this only as part of my looking at the code to identify your problem.) If you didn't see those two annunciators at the same time, it's also possible that you might have hit the battery emergency disconnect switch on the left of the pilot's subpanel.
From the looks of it, vPilot must use the "CIRCUIT_GENERAL_PANEL" generic electrical circuit to identify when your radios should be working or not. I have that circuit connected to the hot battery bus to serve as the King Air's "avionics memory" circuit. Unfortunately, using only one circuit to determine if an aircraft's radios are functioning is quite limiting for more complex aircraft. I also don't blame the developers of vPilot, since that's an easily accessible variable that would usually be on the avionics bus. Knowing what I know now, I would not have set up the King Air this way, as I have learned just how many 3rd party addons rely on that variable to read the avionics power state. I will make a note of this for myself for future development.
Answering your question, I don't believe there is a way to reset that failure without reloading the aircraft, unfortunately. Again, I would have included a reset for that failure with the weather radar's "recharge battery" option if I were designing the aircraft today.
