Big current draws:

Gear
Windshield de-ice
Prop de-ice
Pitot (which includes stall warning)
Headlights

Nothing really big, but lots of little things. About 40 or more circuits. 95 amp alternator and 7 amp standby generator for emergency use.

So far seven electrical system failures over 20 years from things like alternator and alternator control failures to broken field wire, failed alternator CB, broken belt, etc.

In 16 years of driving bus three alternator failures and one failed field wire. I guess if it is mechanical it will break.