I seem to have a problem with my key fob battery needing to be changed almost every week to two weeks. I change out the battery and everything is fine.....until I have to change it again after a week or two. It's getting to be a pain in the a**! Anyone have this problem with premature battery drain with their key fob? Any ideas on what could be the problem and how to fix it? Thanks.

 

I would possibly try to take it apart and clean the connections and see if that takes care of the problem. If not you have a good excuse to upgrade to a Carrera GT key design For more information Click Here.

 

I seem to be having the same problem. I put a new battery in, it was at ~3.2v. Maybe a week later it's down to ~2.8v.
Looking at this graph, it should take it a long time to get to 2.8v
http://data.energizer.com/PDFs/cr2032.pdf

Either way, with a fresh battery i can unlock the doors from a reasonable distance. After a week or two i have to be right next to the car, and even then it works intermittently.

 

I ended up ordering two new remote controls to replace my faulty remotes. Apparently, after repeated use the remotes start to develop cracks in the soldering connections from the printed circuit board flexing from the pressure of pressing the remote buttons. That results in a constant drain of the battery. I have an local Porsche mechanic who is going to program my remotes for $85 once they get here.

 

An update - I cleaned the electronics in the key thoroughly (including unsoldering the battery holder) with some contact cleaner and a toothbrush, and my key seems to be working much better (so far).
In the 5 days since i cleaned it the battery hasn't dropped in voltage at all, and it appears to lock/unlock the car far more reliably. Before i cleaned it, the battery dropped from 3.2v to ~2.8v in about a week.

Either way, the cleaning was warranted because the key went through my washing machine a year or so ago. I had forgotten about it, and at the time it didn't seem to have done anything to the key. My dad, an electrical engineer, suggested this after i told him the symptoms and it makes sense. Once the detergent dried on the electronics, it became a weak conductor between some of the pins of the ICs, causing a short which drained the battery over a couple weeks.

In short, it could be caused by some crap on the underside of the battery holder. Try cleaning it off and it could take care of the problem.