chitownbob

Nope, nothing. I called the guy on Friday. He let it sit for 2 days and the battery was dead so he said there is a definite battery drain. He is gonna go through it next week. I'll tell you what he says but please let me know of any ideas you guys can think of.

chitownbob

car has been at the dealer for almost a week now. The manager let it sit for 2 days adn it went dead so he confirmed the drain but has yet to find it. Has anyone had this problem before?

996blue

just a thought....

maybe you have a bad alternator (not charging up the battery during driving) which would eventually run down any battery.

experience: old VW GTI bad ignition switch which messed up the electronics which messed up the alternator which messed up the battery.....

can't say a Porsche is the same as a VW but those Germany guys get around.

otherwise try the trickle charger (works well for me).....too many weeks of sitting idle and frequent run-downs will kill most batteries.

bpr

I had my 996 C4 in the shop yesterday for them to check why my battery keeps dying, even after just two days w/o driving my car. They said that my electrical system was just fine, and ultimately I need a new battery (even though my battery is <2 years old). They said that Porsches are notorious for drawing a significant current even when the car is off due to the computer, radio, and a few other items. Still, it seems that a battery should last for more than 2 years without dying every couple of days. Anyway, the bottom line for me is that I need to either drive my C4 every day to keep recharging the battery or get myself a trickle charger that I use regularly. In the meantime, I need to buy a replacement battery.

1AS

If it's gone flat a number of times, you could need a new battery that often. The unanswered question is why is it going flat so rapidly? Eagerly await the dealer's solution. AS

chitownbob

bpr, that doesnt' sound right though. Several others have said that they leave their cars sitting for several weeks without a problem. Although there is a battery drain it shouldn't drain it so rapidly in 2 days that you can't start the car. I replaced my battery with a new optima battery a week before sending it to the dealer and it went dead within a couple days again. Thats why I don't believe the battery drain explanation. I don't think my alternator is bad either because if I start it every day there are no battery issues. I'm gonna call him later today to see if they found anything. If I were you I'd change the battery out immediately and see if your problem is solved.

path

Chitownbob,

I was under the impression that Optima didn't make a battery to fit Porsche's. I'd be very happy if you tell me I'm wrong. By the way, congrats on your Cubs win.

Pat

chitownbob

Thanks, Im a White Sox fan but am cheering for the Cubs. Optima doesn't make a battery that fits the 996 exactly but there are instructions somewhere on this site that shows you how to do it. Underneath the battery is a removable battery tray. I removed it, drilled a hole into it and then secured the battery to the tray directly with a screw. The optima battery came with holes on the bottom. THen i just reattached the tray. The instructions called for replacing the positive cable becasue it was short but I was able to use the owm cable. Its not a perfect fit but works well. I chose the optima becasue it was more powerful than the OEM battery. Also it was sealed so I didn't need to worry about battery fumes getting into the cabin. You have to be careful of that because if you notice, the air filter for the HVAC is located directly next to the battery.

Bob

bpr

chitownbob -- I agree that it doesn't sound right that my battery is draining so quickly. I'm getting a new battery tomorrow and will see if that solves the problem. If not, the car will go back in the shop for them to diagnose what's at the root of the problem.

Bob Rouleau

chitown

It sounds like you have a drain problem. Often the light in the luggage or engine compartment. Once a battery goes dead, there are good odds that you damage the cells and it will not take a charge ever.

My 993 could go about a month without being started. My GT2 about three weeks but I have a (mandatory) tracking device which always drains some current.

chitownbob

Its been two weeks with no drain found. What is the procedure porsche uses to find such problems? Is there some diagnosic's program that can be used?

Thanks
Bob

ebaker

First you disconnect a battery terminal and connect an ampmeter to measure the drain in milliamps. Then, watching the meter you pull fuses until you locate the circuit causing the drain. Be sure you have the radio code.

chitownbob

Hey ebaker

Which battery terminal do you disconect. I am not an engineer so I don't understand how the ampmeter would locate drain when the battery is disconnected?

THanks

Bob

LanceK

Didn't see this mentioned previously but it happened to me so I 'd thought I'd jump in.

My battery was going dead after 2-5 days when I first got my car. It turned out to be my V1 that I always left on!

I was able to leave previous radar detectors on all the time without a problem but I was told the V1 drains more power.

Maybe you removed the detector before bringing it to the dealer and therefore the service department ruled out that possibility?

chitownbob

I thought it was the radar also but the drain has been happening for the last month or so. I had a k-40 installed which shuts down with the ignition within the last month so it has nothing to do with the radar since the problem started before the k40 was installed. thanks for the input though.

bob