My 99 Ranger 3.0 is only being driven once a week if that,,I had to charge the battery yesterday,,i do not think it is being driven enough to keep the battery charged. my guage is about half way( in the middle when truck is being driven) and not sure what the exact voltage is.If I use my volt meter at the battery when truck is running what should the voltage output be with full charge on the battery???? Should I turn on headlights and see if that voltage changes ??? I just guessing it should be about 13 volts with lights off and about 14.5 with lights on,,,but I am just guessing at these volts. So any help here would be great just to make sure my alternator is working right.

 

With a multimeter the battery should measure about 12.5v with the engine off, and with the engine running you should see 13.5-14.5v depending how many electrical loads are on.

 

Thanks that is exactly what i needed to know,,,will check it with my meter first thing tomorrow

 

You might want to use a solar charger, just make sure, if using the cigar lighter plug, it's hot with the key off.