chitownbob

Hi, Im a new member and I need some help. I just purchased a 99C4 with 19K miles on it about 2 months ago. A few weeks ago the battery went dead. I jumped it and a couple days later it went dead again. After jumping it again for the second time, I made sure to start and drive it at least every other day. Then I had to go on a trip and whebn I got back it was dead. One of the other threads said that porsche batteries went bad without notice and were weak and recommended the opitma red top battery which I purchased and installed. I continued to start and drive it every couple days. Then I let it sit for about 5 days and it went dead with the doors locked. As many of you know, this is a total pain in the butt. The dealer sent two tow trucks and finally the service manager to get the car back to the dealer. The dealer is going through it, looking for what keeps draining the battery. So far they don't know what the problem is. Does anyone have any ideas as to what it may be? I though it may be a broken trunk or hood light that wouldn't shut off but that isn't it. they also ruled out the alternator.

Thanks

DonW-Cape Cod

I have no idea what the cause might be, but it might be wise to have a "trickle charger" handy. I use one now if I know I'm not going to drive for a few days.

Loren

A five year old battery is a five year old battery -- regardless of miles. My MY99 has 14k miles and I expect the battery to go any day

chitownbob

well, i replaced the battery with an optima red top just a week ago and it went dead also, so it isn't a problem with the battery. THe althernator looks okay too because if i started adn drove it every few days the battery looked good.

Thanks

Bobby

Trojan Man

My OEM battery had to be replaced after only 2 years. The service guy told me that Porsche OEM batteries are not designed to last very long and that they have much lower CCAs than many other batteries.

If you have an older battery and don't drive the car but every 5-7 days the battery will discharge.

I have since bought the Porsche Battery Maintainer and I've had no problems.

BTW, the dealer replaced my battery under warranty (100% free of charge). I always thought that battery warranties were pro-rated.

Loren

You have a power drain then. Best start looking for the obvious -- like the front trunk light no shutting off (broken switch), rear light, etc.

bpr

I, too, bought a 1999 C4 a couple of months ago, and I'm having problems with my battery dying frequently. It seems that if I don't drive my car at least every couple of days, the battery will die. I have 20K miles on the car, and it's on its second battery. I'm bringing it to the dealer to have it checked out on Monday. So if I find out anything useful, I'll let you know.

chitownbob

what are some common battery drains that I should be looking for?

Tool Pants

A coomon drain is leaving the key in the ignition after you turn the car off. But since you said the car was locked.....

Trojan Man

Dealer says that there are so many computers onboard that there is a natural power drain even with all lights & ignition off. They recommended starting the car and letting it idle for 5-10 minutes at least every 5 days if I'm not going to drive it. Either that or use the trickle charger.

chitownbob

That's crazy. I have a LS400 with 175000 miles on it and if I leave it in the garage for 2 weeks it starts right up. Your telling me that if I leave my 911 for 3-5 days that it won't start at all. Not only is that terribly inconvenient, but it is also dangerous. My battery went so dead after sitting for only 5 days that it had to be towed to the dealership because the hood would not unlatch. Sorry to b*tch but although the car has awesome performance, I might need to get something else if the car dies like this. The trickle charger is for long term storage so that the battery will not go bad, and is not for daily use. It is a temporary solution to the problem. My SC430 sits for weeks in the garage in cold Chicago winters, starts right up and I know that thing is one big computer that drains the battery. The dealer is looking for the prob as we speak but has come up with nothing. Thanks for your suggestions as of thus far though.

1AS

Chit, your experience is atypical. I own an 02ttX50 that will go flat in 2-3 weeks, but not in the few days you describe. You clearly have a drain. I'd go over the really simple things first (speaking from experience-having left an under dash interior light on in my son's Alfa and going thru your process)
Like- no cell phone charger on, headlights and turn signals definitely off. I'd look at the car in a darkened garage after turning it off to see if there are any hints. After that it will be up to the dealer. By the way, I have a BMW 850 that will go a little longer before going flat...but it has 2 batteries in the trunk. AS

chitownbob

you guys think that a battery cutoff switch would help if you don't drive the car for periods of time. I dont' care for radio settings much. Here is a link to what i am talking about

http://www.performanceproducts.com/P...producttype=10

Brian Lopez

I have a 99 C2. I have left it sit for up to a month at a time, the keyless entry stops working and the blinking light on the dash goes out automatically. That said, it always had started on the first try, original battery. Maybe I'm lucky, but the dealer bit about constant computer drain sounds like bs to me.

Happy hunting...

ebaker

If everything is right it should start after sitting a month or so. The computer shuts down most of the current drains after it sits 5(?) days. Are you leaving anything pluged into the lighter?