It can put out too many volts and destroy the battery but not drain it. The alternator should put out between 13.5 to 16 volts.
The battery is 12 volts but the alternator generates about 13-14v to charge the battery.
The inverter isn't run off the alternator... it's run off the battery. The alternator simply recharges the battery.
The alternator should be putting out between 13.5 and 16 volts on a good alternator with the engine running as measured with a DC volt meter at the battery posts. Any less or any more and the alternator is defective of the belt is slipping.
With engine running at idle you should read 13.5 to 15.5 volts at the battery.
Bad ECU, replace.
generally if you hook up a multi-meter to the battery and start the engine it should read 13.5 or 14 volts, when you turn on headlights and other accessories the alternator should keep the battery charged up to at least 12 volts, you can also just check the battery to see how many volts it's putting out before you start the vehicle
With the engine running you should read from 13.5 to 15.3 volts at the battery with no lights or accessories on, with a nominal voltage at idle of 13.8 to 14.2, depending on temperature and battery state. Any less or more and the alternator is bad.
The gauge inside is telling you how many volts your alternator is putting out, not yoru battery. Go have your alternator tested to see if it is putting out 14 volts or more...........if not, you are drawing more current out of the battery then what the alternator is replacing and you are going to end up with another dead battery. They can test alternators at Autozone for free or you can go get a multi meter and test it yourself. Have the alternator checked.
If the alternator is functioning properly you should read somewhere around 13.5 to 15.5 volts DC at the battery with the engine running at idle.
13.5-16 volts DC
1.55 volts
13.5 to 15.5 volts