Normal parasitic battery draw.. - Rennlist Discussion Forums



Normal parasitic battery draw..

Reply
 
Thread Tools Search this Thread
Old 01-08-2011, 12:40 PM   #1
mojieboy
User
Thread Starter
 
Join Date: May 2006
Posts: 14
Default Normal parasitic battery draw..

Hi Guys,

Simple one this... I recently replaced the battery in my 1991 944S2 because the old one was continually going flat after about a week (it was only about 3 years old), I am trying to double check that the new battery won't have the same problem.

what would you expect the normal parastic draw on a battery to be?...

Using a multimeter with everything switched off and the car locked i found the draw to be 0.3 amps.

Does that sound about right?
mojieboy is offline   Reply With Quote
Old 01-08-2011, 01:46 PM   #2
Makis
User
 
Join Date: Oct 2005
Posts: 186
Default

It should be much less then that more like 10 times less. Do you have the battery in the boot or in the engine bay? Is possible that with the bonnet up there is more current drawn because of the alarm system. If the battery is in the boot you can just make the measurement from inside the car with doors locked. Usual culprit for excessive parasite draw is the stereo.
Makis is offline   Reply With Quote
Old 01-08-2011, 03:02 PM   #3
xsboost90
Now Cool
Rennlist Member
 
xsboost90's Avatar
 
Join Date: Jan 2003
Location: cincinnati,OH
Posts: 15,212
Default

most the time the door pins for the lights stick or dont release fully. This leaves power to interior lights or power windows etc and it kills the battery. Try pulling the door switches and testing them for on/off function.
xsboost90 is offline   Reply With Quote
Old 01-09-2011, 09:03 AM   #4
Mark944na86
Addict
Rennlist Member
 
Mark944na86's Avatar
 
Join Date: Jul 2001
Location: Brisbane, Australia (Formerly: Sunnyvale, CA)
Posts: 2,121
Default

Quote:
Originally Posted by xsboost90 View Post
most the time the door pins for the lights stick or dont release fully. This leaves power to interior lights or power windows etc and it kills the battery. Try pulling the door switches and testing them for on/off function.
Even easier is to see whether they switch your interior light(s) on/off. You don't have to pull the door switches to test that.

If they aren't working, it's the power to your power windows that draws the excess current that flattens the battery.

By design, power is supplied to the power windows after you switch the engine off until the door is opened. If a door switch doesn't work, the door open is never sensed, and the power to the power windows persists indefinitely.
Mark944na86 is offline   Reply With Quote
Old 01-09-2011, 10:05 AM   #5
John_AZ
Proprietoristicly Refined
Rennlist Member
 
John_AZ's Avatar
 
Join Date: Oct 2001
Location: ~Carefree Highway~
Posts: 1,782
Default

My amp draw on the '88 is a bit over 9ma.
My amp draw on the '87 is about 8.65ma.
My only draw is the radio presets. No alarm.

Clarks says it can be as high as 60ma That is very high--too high I think.
http://www.clarks-garage.com/shop-manual/elect-26.htm

I use a cheap Harbor Freight VOA meter. Set it HIGH on the amps setting-then lower or you will blow the fuse inside. Just pull one fuse at a time until the number drops per Clarks.

GL
John
Attached Images
  

Last edited by John_AZ; 01-09-2011 at 05:25 PM.
John_AZ is offline   Reply With Quote
Old 01-09-2011, 11:37 AM   #6
Sour Kraut's 951
User
 
Sour Kraut's 951's Avatar
 
Join Date: May 2010
Location: Inside my own Head for now.
Posts: 294
Default

After working in auto stereo for over 20 years the found magic number is 5 milliamp of draw. This has always been a concern for anyone who has ever installed an alarm and than parks their car at the airport. If you want to take a 2 week trip anything over 5 ma will usually drain the battery dead. This is why most new cars have a rundown protection circuit that disables all accessories until the unlock command is received from the keyless entry. Bad grounds, has that been said here before? Check them all. If you have just one bad ground you will have a higher than normal draw on your system. Always make sure the battery is fully charged. Not at 20 amps but at the lowest charge rate will give the best results, like a maintainer that puts out 2 or less amps of charge. If it is a lead acid battery, are we still using these, top off the water. Each time a battery is discharged and charged you will loose reserve capacity, hence less allowable sitting time between starts. But again I am sure it has been said but it is milliamp and not amps of draw that you want to see.
Sour Kraut's 951 is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Parasitic draw found! czentner 944 Turbo and Turbo-S Forum 7 07-12-2016 10:45 AM
Battery drain issues continue fpena944 996 Forum 38 10-02-2015 12:30 PM
BIG spark connecting battery noodlehouser 997 GT2/GT3 Forum 5 07-15-2015 09:46 PM
2003 C4S Battery Drain Rpompea 996 Forum 5 05-28-2015 04:19 PM
Battery drain problem, I have tried everything.. zenithblue993 993 Forum 19 05-12-2015 09:00 AM


Tags
86, 964, alarm, amp, automoble, bad, battery, car, current, drain, draw, excessive, ground, interior, normal, parasitic, porsche, switch, system

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -3. The time now is 07:10 AM.


Copyright ę 1998 - 2015 Rennlist.com