With everything on IE air-con lights etc what should the voltage be across the battery??

Same with everything off.

I Get 13v with everything off
and from 11.5 to 12.5 with everything on .

Anyone got an idea of what it should be MINIMUM for both??

Cheers

 

it sounds about right to me does the voltage recover when u rev the engine voltage can drop momentarily on crank to 9 volts

 

If 11.5 to 12.5 was with the engine idling then that's fine, so long as by 2000rpm it is high 12's or low 13's then that's fine.
tabetha