Battery Draining
Thread Starter
Advanced
Joined: Aug 2006
Posts: 92
Likes: 0
Battery Draining
If i don't drive my car for a couple of days the battery drains it self and I need to jump start the car. Normally I just disconnect the battery if I know the car isnt going to be used. But I was wondering if you could tell me what the problem is and how it could be corrected.
I have cleaned all the leads to the battery and I never leave anything on when the car is off.
Suggestions please
thanks
I have cleaned all the leads to the battery and I never leave anything on when the car is off.
Suggestions please
thanks
Drifting
Joined: Aug 2006
Posts: 2,890
Likes: 75
From: Reno, NV
You'll find many posts on this subject in this forum if you do a search. Mine included. Get a decent multimeter and start checking stuff by disconnecting and seeing if the power flow changes. The first place I'd start is with anything 3rd party added on, such as stereo/amps, radar, etc. My issue was indeed with the added on amp.
Drifting
Joined: Sep 2006
Posts: 3,379
Likes: 128
From: Stratford-upon-Avon
Originally Posted by UNTS1
If i don't drive my car for a couple of days the battery drains it self and I need to jump start the car. Normally I just disconnect the battery if I know the car isnt going to be used. But I was wondering if you could tell me what the problem is and how it could be corrected.
I have cleaned all the leads to the battery and I never leave anything on when the car is off.
Suggestions please
thanks
I have cleaned all the leads to the battery and I never leave anything on when the car is off.
Suggestions please
thanks
IIRC anything over 50mA drain is suspect. The drain should only be from radio (memory) and alarm circuits and maintaining memory in the LH 'brain' I think, but I may have forgotten something!
Expose your fuse panel and methodically pull fuses, checking the drain after each one and make notes of results.
Go through the figures and see if any circuit which is meant to be completely off with ignition off is drawing current. Could be you have a stuck relay so armed with list of suspects you can start pulling relays and checking drain as above.
Be very carful pulling relays with the battery connected as they're very tight, so it can be easy to create inadvertent short prying out the base with angled tool etc.
Best,
Adrian
Thread Starter
Advanced
Joined: Aug 2006
Posts: 92
Likes: 0
Thanks very helpful post, but i don't know where the ground cable/strap is.
Can you post a photo of what it looks like and where it is. I read in another thread that its to the right of the engine, I looked but was out of luck, and from the previous 10 page thread this problem sounds quite hard to fix, hopefully my problem is simpler, my worst case scenario is to make a switch that disconnects the battery and have the switch located somewhere easy to access.
Can you post a photo of what it looks like and where it is. I read in another thread that its to the right of the engine, I looked but was out of luck, and from the previous 10 page thread this problem sounds quite hard to fix, hopefully my problem is simpler, my worst case scenario is to make a switch that disconnects the battery and have the switch located somewhere easy to access.
Instructor
Joined: Aug 2006
Posts: 232
Likes: 1
From: Melbourne Australia
Hello their UNTS1,
I live in Melbournes west, if you would like to have some help, I could drive over and give you a hand to sort it out if you like. My 928 can sit for over a week and startup like it's been sitting for a minute. We could compare notes as such.
Regards,
Glenn
'81 928
I live in Melbournes west, if you would like to have some help, I could drive over and give you a hand to sort it out if you like. My 928 can sit for over a week and startup like it's been sitting for a minute. We could compare notes as such.
Regards,
Glenn
'81 928
Rennlist Member
Rennlist Site Sponsor
Joined: Jun 2001
Posts: 6,469
Likes: 13
From: Ball Ground, GA
With a battery drain on a "totally stock" (and that means NO aftermarket stereo), the first questions probably should be:
- Do your interior lights work exactly as designed? Do they come on when the door opens and go off when the door closes?
- Is the glove box light on all the time?
- Is the under-hood light on all the time?
- Do you park the car with the keys in the ignition?
- Do your interior lights work exactly as designed? Do they come on when the door opens and go off when the door closes?
- Is the glove box light on all the time?
- Is the under-hood light on all the time?
- Do you park the car with the keys in the ignition?
Trending Topics
Instructor
Joined: Nov 2005
Posts: 184
Likes: 0
From: Alberta, Canada
Are you sure the stereo is stock?????
That is where my battery drain was occurring. The car charged fine, 13.90V range at battery with car running, around 12.8V at battery without engine on. Let car sit 3 days, dead, remove stereo, no more problems
That is where my battery drain was occurring. The car charged fine, 13.90V range at battery with car running, around 12.8V at battery without engine on. Let car sit 3 days, dead, remove stereo, no more problems
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)
Joe Kucinski
Porsche Shakes Up The Nürburgring Lap Record Table Once Again
Verdad Gallardo
6 Ways the Porsche 911 GT3 S/C Redefines Performance
Joe Kucinski
10 Wildest Homologation Specials Porsche Ever Sold
Verdad Gallardo
Super Rare RUF BTR III Comes Out of Hibernation, Looking For a New Home
Verdad Gallardo
Rennlist Member
Joined: Mar 2002
Posts: 6,115
Likes: 344
From: Texas
Also to add to what Wally said in the post above, the red lights in the end of your doors need to go out when you push in the button(like you were closing the door). It is difficult to see that they are on all the time when you close the door, but they are battery killers.
Stratford Shark has given you the best way to find all your battery drains, though. Good Luck!!!
Stratford Shark has given you the best way to find all your battery drains, though. Good Luck!!!
Rennlist Member
Joined: Jul 2001
Posts: 6,561
Likes: 113
From: New York
The dome light has been cited by many. You really need to wade through the many posts on this. This is one of the many things this car demands of ownership. You will learn where the ground strap is and much more. In the new visitor thread, #33 you will see a list of the multiple groundings on this car.
http://www.nichols.nu/tips.htm
http://members.rennlist.com/pirtle/keepers.html
are but two of several sites that you will want to read.
HTH.
http://www.nichols.nu/tips.htm
http://members.rennlist.com/pirtle/keepers.html
are but two of several sites that you will want to read.
HTH.
Thread Starter
Advanced
Joined: Aug 2006
Posts: 92
Likes: 0
Originally Posted by WallyP
With a battery drain on a "totally stock" (and that means NO aftermarket stereo), the first questions probably should be:
- Do your interior lights work exactly as designed? Do they come on when the door opens and go off when the door closes?
- Is the glove box light on all the time?
- Is the under-hood light on all the time?
- Do you park the car with the keys in the ignition?
- Do your interior lights work exactly as designed? Do they come on when the door opens and go off when the door closes?
- Is the glove box light on all the time?
- Is the under-hood light on all the time?
- Do you park the car with the keys in the ignition?
Instructor
Joined: Jul 2002
Posts: 193
Likes: 1
From: Florida
If you have an 87' or newer 928 there is a power stage amp for the fans, if there is a short with it, it would drain the battery in one day. This power stage amp is located in front of the radiator - it looks like a CD ignition unit.
Thread Starter
Advanced
Joined: Aug 2006
Posts: 92
Likes: 0
Originally Posted by SteveG
The dome light has been cited by many. You really need to wade through the many posts on this. This is one of the many things this car demands of ownership. You will learn where the ground strap is and much more. In the new visitor thread, #33 you will see a list of the multiple groundings on this car.
http://www.nichols.nu/tips.htm
http://members.rennlist.com/pirtle/keepers.html
are but two of several sites that you will want to read.
HTH.
http://www.nichols.nu/tips.htm
http://members.rennlist.com/pirtle/keepers.html
are but two of several sites that you will want to read.
HTH.
But there is still one thing I'm not sure of.
Originally Posted by tip site
disconnect your battery ground strap, attach one probe of the meter to the ground strap and the other probe to chassis ground.
Sorry Im not too good with cars but I'm willing to learn. (I'm very young
