Hi Scott,
If you've got an alarm or radio with a permanent battery connection then it
might be slowly draining the battery. There isn't anything in the factory
wiring that would have a constant current draw, so if you think there is
something that is pulling current all the time, just check all the
electrical accessories with a voltmeter and see if anything is powered on
when it shouldn't be.
You should make sure that the battery is not draining itself through crud on
the exterior. Wash the top and sides of the battery with a dilute baking
soda mix, rinse with clear water, and dry it. Make sure the battery is
sitting on an insulated tray.
Lastly, I can't remember my lead/acid chemistry completely, but isn't 12.0
volts the nominal terminal voltage for a car battery? It will be at 12.6 for
a short while after you've run the car but it will basically sit at 12 volts
until it reaches something like 20% charge, at which point it will start to
droop. You should definitely worry if your battery self-discharges to below
11 volts in a week, or if the voltage drops significantly when you turn on
the headlights, but having the battery at 12 volts is not necessarily a
cause for worry. If this is wrong I hope someone will jump in to correct
me...
Best regards
Theo
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