if the alternator is working properly it should always put out between 13 and 15 volts
13.6 to 14.5 volts with all accessories turned on, depending on temperature.
bad voltage regulator, should not go passed 14, should not go below 12
With a fully charged battery (12.68 volts) and engine running at idle with no accessories on, 14.5 volts. You will not get a accurate reading if the battery is not fully charged.
neither...it should have 14.63 volts
Fully charged battery should have 12.6 volts. 75% charged 12.4 volts, 50% charged 12.2 volts, & 25% charged 12.0 volts.
Automotive Battery VoltagesAssuming your voltage meter is accurate, the battery is fully charged, when the key is turned on, without the engine running, and no accessories turned on, the meter indicated voltage should be 12 volts. When the engine is running and the alternator is charging the battery, the voltage should indicate anywhere between 13 volts to about 14.6 volts.Answer 2 - A wider Acceptable Range13.5 −16 volts is acceptable with the engine running.
12 volts DC.
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.
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
13.5 to 15.5 volts
From 13.5 to 15.5 Volts.
13.5 to 16 volts DC.