Hi there,
I am having a problem with the 310 and the people from discord couldn’t help me either. For some reason there is something wrong with my battery and it runs out mid flight. I have failures both from the tablet and the in game menu off and it keeps on happening. My battery runs out, but still keeps some instruments working. For example if I turn off my battery, the airspeed gauge stops working. but after pull back the engine throttle enough so that the alternators don’t produce as much electricity and the battery has to kick in, all of my avionics turn off, but my speed gauge and other analog instruments still work and it only happens after about 20 mins of usage (both flying or on ground). The problem seems to be, that the battery isn't charging, but I still can't figure out why. I am following the checklist every time and all of the circuit breakers are all in.
Let me know if you know any fixes.

I know this is not the real answer, but if you have FSUIPC, it has a feature which creates an everlasting battery. That might help, and I think that feature is also in the free version.

Cheers

Try toggling the failures on and inspect/overhaul then turn it back off. Try it without any other add-ons in your community in case something is interfering. I believe I had 1 other person report this before but I couldn't locate the resolution. I suspect it was another add-on or something in MSFS.