It should output the same voltage that any 12volt battery system outputs. Roughly between 13 and 15 volts (13.3-14.9)
13-15
13.6 to 14.5 volts with all accessories turned on, depending on temperature.
As many as you want. But where do you find 640 volts RMS?
A fully charged 12 volt automobile battery will read 12.6 volts with the engine not running and 13.5 to 15.5 volts with the engine running. It will read 12.4 volts with a 75% charge, 12.2 volts with a 50% charge and 12.0 volts indicates a 25% charge.
Cars don't charge alternators; alternators charge cars. If your new alternator isn't charging, it could be your battery is bad or your battery connections are corroded. Another thing it might be is your voltage regulator. Many alternators come with built-in voltage regulators, but if your system has a standalone v.r., it could be bad too. Finally, if your 'new' alternator is actually a refurbished or rebuilt one, it could be a bad rebuild. It happens.
around 14-14.5 volts
13-15
13.5-16 volts DC
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.
13.5 to 15.5 volts
From 13.5 to 15.5 Volts.
From 13.5 to 16 volts.
13.5 to 16 volts DC.
12 volts
It should put of 13.5 to 15.5 volts. The alternator is an 80 amp alternator.
Most likely 12 volts if it is on a car. Some boats use 24 volts, or in the case of my boat 32 volts.
13.6 to 14.5 volts with all accessories turned on, depending on temperature.