Overcharging
Gauge doesnt have numbers on it. I only see one br. I agree it shouldnt have anything to do with it. However it changed the reading at the battery. The car was at idle. Battery a little weak from me cranking on it til I figured out no spark. Battrry is new.
It may be just normal charging.
The ammeter
shows 40 to 0 to 40 amps. When someone jumps in an existing thread, I assume they've read through it.
If its charging at 20 amps for a minute and then starts to drop toward zero, that would OK considering the battery is probably pretty run down.
If it's pegging the 40 amps - that's not good, but can happen with a depleted battery and some alternators - especially at fast idle.
But also could indicate something is wrong. In either case, the wiring can get overheated and damaged, and the battery acid can get boiled out.
If its an traditional battery the charge can be checked with a cheap hydrometer (battery checker with 4 or 5 balls in it).
A very rough idea of the condition can be estimated using a voltmeter.
Engine off for a few minutes or more, a fully charged battery should be around 12.8 Volts.
During start, a weak but good battery will drop under 10 Volts, and if below 9.6 almost certainly needs a charging.