[JFP in PA]

Originally Posted by Mike_Yi

I've had my Boxster for a bit over a year. I once went to go to work and it wouldn't crank. However, this was after I had it in the garage for several days with the doors open (and, as a result, the courtesy lights on) while putting in my racing seat.

Last week it got really cold here in Chicago. I think it was 4 degrees with a -15 wind chill. I had some errands to run and the car cranked slowly, but started immediately. I thought it was just the cold. So over the next few days it warmed up a bit (but it IS Chicago, so not that much), but the car continued to crank slowly, but start immediately. Yesterday I got in the car to leave for work, and nothing happened when I turned the key. Everything turned on, but the solenoid didn't click and the car didn't crank.

Today I pushed it in the garage and put it on a charger for about 2 hours. The car cranked fine. I drove it for about 20 minutes and shut it off. It started again no problem. I drove it about 5 minutes, shut it off and it started again. Drove it 2 or three minutes, shut it off again, and it started fine again.

I took the battery to Advanced Auto Parts and had them test it. They said it was fine, but it needed to be charged.

The car sits outside in the Chicago winter in the driveway. Usually, I start it and drive it 1/2 hour to work, then it sits outside again. I drive it 1/2 hour home and it sits outside again. Is it possible that the cold, plus the relatively short drives depletes the battery a bit more every time I drive it?

It doesn't seem like the alternator is a problem. In the cold the car has the A/C on, the fan on high, the rear defroster running, lights, the stereo, and maybe the wipers. I don't get any dimming of lights that would indicate a problem with the charging system.

What do you guys think?

How did they test the battery? If all they did was run a voltage test, they wasted your time. The only true test of a battery is to fully charge it, let it sit and cool, and then load test it. You cannot run a proper load test on a partially discharged battery. A load test is a "pass/fail" test, the battery can either deliver the amps or not.

From what you describe, it has all the earmarks of a dying battery.......