battery voltage

With engine running you should have about 14 volts at the battery terminals and about 12.5 volts when it's off. Any reading much different, you should have the battery and alternator tested.

What would that look like on the gauge? Mine stays in the center and sometimes varies a bit to either side but very little

MY vehicle jeep grand chrokee l 2022 stop-start ready after 24 hours engine shut off stop- start not ready after that need to driving 40 km to ready is drop volte normal of auxilary battrey.I will changed battrey to new