Battery voltage - what should it be?

[alexandjen]

Checked mine today - reading 12.4 Volts  :-/

Is this good or bad (engine off by the way)

[Dave DND]

Battery voltage on its own is not necessarily a good indicator of a good battery - you need to perform a load test on it.

Most battery suppliers / garages will perform this check for you free of charge.

Voltage across battery with engine running usually around 13.8V

[zirk]

Battery voltage of a stand alone battery of between 12.4 to 12.8 volts indicate that it is fully charged. But as DND say's means nothing compared to a Load Test or a good current drain.

A cheap test (if you have a DVM) is to put the Meter accross the Battery when its cold (ie in the morning) with a cold Engine, switch everything on, ie' Heater, Lights, Rear Heat what ever, then Crank the Engine, hopefully it should start but while its cranking the Batt volts should not go below 9.7 volts. (this indicates a good battery, anything  lower than this for a recently charged battery means the battery is duff).

zirk