96 Mustang GT.
When I drive it the battery charge indicator slowly starts going down. Depending on whether the lights are on and other eletrical equipment, this drain can be very, very slow or slightly faster. The headlights never dim, etc, but the charge indicator will continually go down.
But here's where it gets weird;
I'll park the car with the battery indicator showing it almost to the "N" on the word "NORMAL", but no matter what, the next time I go to drive it, which sometimes is a week or 2 later it always starts at the same charge rate which is around the R-M area of the word NORMAL and has no trouble starting.