Yes I agree, most of us have charged a battery while it was in a car.
Yes, those are common reasons for a battery running down. Leaving an
interior light on for an extended time will do it too.
Well, I've had to remove batteries when they wouldn't hold a
charge. I've also learned to periodically remove a batttery to clean
any oxidation from the battery compartment. Reduces the chance of
oxide from the battery rusting through the body.
