A fully charged battery should make about 13.2 volts with no loads applied. Lead acid batteries should make 2.2 volts per cell, 12 volt batteries have 6 cells.
In order for the battery to be charged the charging source output voltage must be greater than battery voltage. With the engine running you should see somewhere around 13.8 to 14.8 volts.
If the battery terminals are clean and all your inspections have found the battery to be in good condition check the ground wire connections where they are attached to the engine or the car's frame. Remove the ground and check the area under the cable's terminal looking for corrosion. Clean all corrosion with a wire brush and then reattach the cable and apply battery terminal protector to the ground attachment.
Last edited by JSmith; 03/17/03 05:56 AM.
