dr90254

Hopefully someone here on Rennlist can help me out. So my 2004 996 c4s cab was running beautifully, until around 15K when I kept having the battery die and I would have to jump start it every few weeks, which grew to every few days.

The dealer said I had to drive it every 2-3 days to keep up the charge. Eventually I replaced the battery around 24K (at a tune of $400), but the battery died 10 weeks later. Now, this was when I was driving it every 2-3 days as the dealer suggested. Now, at that point I jump started the car and then it ran fine for a few months.

Then last week the battery was very very dead, I took it back to the dealer and they told me that just driving it every 2 days isn't enough, since I only drive it a few miles a day, that I need to buy a trickle charger ($130) and charge it every night. they told me they checked the battery and it was 25 mA (they said anything over 30 was bad). Is 25 mA too high? Could there be something else draining the battery, like some electrical problem, that would cause it to be 25?

Now, I bought a Porsche because I wanted a sports car, not a stupid electric
plug in -- what the heck? I want to know from you guys whether you think this is normal, and yes, I need to buy a trickle charger, or whether, as I suspect, there is some electrical draw on the battery that is causing it to draw down. I find it hard to believe that Porsche designs cars that need to be plugged in every night but I admit this is my first 911.



Thanks for your help.

1999Porsche911

If that is the orginal battery, go to Sam's Club or similar and just get yourself a new battery for $50.

Mr. C4

Once a battery is totally drained it will likely short circuit and will need to be replaced. You can charge it 100 times but will not keep it's charge for more than a couple of hours. Get a new battery and then use a CTEK XS3600 charger if you don't drive the car regularly.

gota911

Let's see if I can get our resident battery expert for an '04 C4S to chime in here. Phil.... PHIL are you there?

Sorry Dr, that's an "inside" joke.

Do you have any aftermarket appliances installed on the car, like a radar detector or stereo system? If they were connected to a non-switched power source, they could be draining the battery. Unfortunately, we have seen a few cars that draw from the battery when parked for an extended amount of time. If you are not driving it much, which apparently you are not, then a trickle charger is your first step.

You could begin by checking the draw from the battery and then remove one fuse at a time to see of the dray is reduced or eliminated. This is a little time consuming but can narrow down the potentially problematic circuit. I am sure other will chime in here with some additional assistance.

BTW - Welcome to Rennlist. It is customary for Newbies to post a couple of pics of their car and tell us a little about it. We love P-car pics!

SH || NC

Me:
https://rennlist.com/forums/996-foru...ml#post6027845

Others:

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

https://rennlist.com/forums/996-foru...hlight=charger

HTH

cdodkin

Battery tender isn't a big deal - but get yourself a fresh battery battery first.

I agree with folks above - once a battery has been totally drained, it can be permanently damaged.

I use this battery tender:



http://www.amazon.com/Porsche-Genuin...032258&sr=1-61

I have the unit plugged into the wall, and the cigarette lighter end hanging on the wall of the garage next to the drivers door.

When I pull in - I just roll down the window, reach over and grab the charger lead, and plug it into the cigarette lighter.

Easy and quick - battery is maintained in perfect shape at al times - only cost me $55.

gota911

There is also a notch in the weather stripping on each door to allow you to run the charger wire in that location without damaging the wire when the door is closed.

JDSStudios

Wow Tim, you are being so nice to newbies with no pictures,
that I am ... speechless.

Welcome to the board dr90254

Since you replaced the battery, I would have the alternator and other charging
components (voltage regulator, belt) checked.

himself

Sounds like you might have a problem with the alternator. Unless you have a parasitic drain somewhere, your battery should last more than 2 days. Mine has sat for 10 days with no problems.

Here is a test you can perform. Start the car, drive around for 15 minutes or so and stop. Restart the car, turn on the lights and AC and drive for 1 minute then stop. Restart. If you have a problem restarting, I would have your alternator checked. A second test would be to have the dealer check the alternator
Mine alternator was charging the battery, but at a very low voltage (like 12.2). So if I drove a long way, the battery acted fine. But if I drove short distances, the battery was drained. Multiple short trips back to back would kill the battery pretty quickly for me...

-td

Rob in WA

Ignition switch check out good?

That could cause the drain.

LVDell

Sometimes it's just the battery. They don't last that long to begin with. Have you had the battery checked?

Michael-Dallas

Where is this notch?

Thanks,

///Michael

gota911

Michael,

If I recall correctly, it is in the weather stripping on the bottom of the door, near the the center of the door. I can't recall if it was on both doors or just one. Let me run out to the garage and check....... oh wait..... I don't have a 996 any more!

I don't think I was dreaming when I saw it. Let me know when you find it on your car.

Michael-Dallas

LOL you'll be back in a p-car soon.

I'd check but it's farking cold outside and I'm comfy right here on the couch.

///Michael

C4CRNA

I try to drive my car every 5 days or so.I've had the battery in there for 4 years and no problems. You may have a parasitic drain you will ned to hunt it down. I left my radar detector plugged in for a day and it almost killed the battery.
When you start the car does the voltage instrument reading go to 14 or is it less? if it is less it is the voltage regulator attached to the alternator that is bad.