My battery light came on when I started my car this morning, but it was only dimly lit - not even at 50% brightness. It slowly went out on my way in to work (after about 10 minutes).

My battery is only about 1 1/2 years old. I purposely got one with about 20% more output than the car requires. So I know it can't be a battery issue. The alternator is a rebuilt unit I replaced two summers ago.

The only thing I can think that MAY be creating a draw on the batt is that I don't push my trunk lid all the way to the locked position at night (so I don't have to bother unlocking with the key every morning when I toss my laptop inside and leave for work). I've always assumed that the trunk light is off with the trunk lid securely resting in the down position. The trunk doesn't have to be completely shut (latch engaged) for the trunk light to turn off, does it??

If this isn't it, what else could it be?

 

Check your voltage with the car running at about 1500rpm and see if the voltage is about 14. also ck all the connections to the alternator and battery. And while the car is off too.

The trunk light could be producing a enough draw to drain the battery at night so try to close it and see if it still does it the next day.

 

Or disconnect the bulb