Battery becoming very hot

Good evening. Checking the lights now. Also can a loose alternator belt cause the issue? Thank you

Any steps on the volt checks?
Gosh yes.
Very first thing.
Turn the lights on for 15 seconds or so if its just been running or on a charger.
^ This removes any surface charge which would show on a voltmeter but does not have power.
Measure the battery voltage with everything off. (The ammeter should be at zero)
If its 12.5 to 12.8 Volts, turn on the headlights and see what it drops to. It should still stay above 12 Volts.
^This is a very crude way to check battery condition, but it will show general battery condition.
If its less than 12.5 Volts with everything off, then one reason the ammeter is showing high charge is because the battery is discharged.

Next, Start the engine.
Measure the voltage from battery neg to battery positive.
Note the ammeter reading, and whether the engine is on slow idle or fast idle.
If its over 14.8 Volts or so, the regulator is probably reading low because there is resistance in the connections or wires.

If its on normal idle (650 rpm or so), use your hand to work the throttle lever at the carb to increase rpm. If the voltage increases with rpm, don't let it go over 15 Volts. Let it go back to idle. There's a problem with regulation, there is none.

That's enough for initial diagnose.

If voltage is following the rpms, you can do the test 67Dart273 suggested: Pull the connector off the voltage regulator. Ammeter should swing to discharge (because the ignition is running on battery, and voltage should drop to battery voltage, 12 something.)