battery draining question

[doug davis]

New to me 99 C2 coupe. One night last week my battery mysteriously drained overnight. It has only happened once in the 3 weeks I have owned it.

I read as much as I could find on this subject in previous posts and am now going to track it down (trunk light, "in series" ammeter test etc.), but I have a question before I go through it.

I read that: 1)If you leave the key in the ignition, even if it is off, it can kill the battery and 2) If you leave a manual trans car in gear, it can kill the battery.

I know I left the key (off) in the ignition once and left it in gear once overnight. I can't remember if those times correlated with the battery drain, but what I'd like to know is can either one of these things really kill the battery overnight? I read both these things in previous posts, but I'd like conformation if anyone here knows the facts.

Thanks,

Doug

[Loren]

1. Get your battery tested.

2. Yes, if you leave the key in the ignition some circuits are activated (specifically the airbag circuit). Leaving the key in the ignition is a bad practice.

3. If the problem continues you need to put an amp meter in line with the battery and measure the current draw. An average Carrera should around 40-60 ma.

If it is higher then pull fuses one at a time until you find the circuit with the draw. Once you find the circuit then you find the source of the draw.

[1999Porsche911]

New to me 99 C2 coupe. One night last week my battery mysteriously drained overnight. It has only happened once in the 3 weeks I have owned it.

I read as much as I could find on this subject in previous posts and am now going to track it down (trunk light, "in series" ammeter test etc.), but I have a question before I go through it.

I read that: 1)If you leave the key in the ignition, even if it is off, it can kill the battery and 2) If you leave a manual trans car in gear, it can kill the battery.

I know I left the key (off) in the ignition once and left it in gear once overnight. I can't remember if those times correlated with the battery drain, but what I'd like to know is can either one of these things really kill the battery overnight? I read both these things in previous posts, but I'd like conformation if anyone here knows the facts.

Thanks,

Doug

Leaving the key in the ignition WILL slowly drain the battery. Leaving your transmission in gear, which is what you should be doing, has NO EFFECT on the battery.