Max. current draw with engine off keys in my pocket? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-23-2011, 07:01 PM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: Vancouver, B.C.
Posts: 138
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Max. current draw with engine off keys in my pocket?

Hi guys, Car is 1991 civic 1.5 Liter, a real eye-turner, I know. Anyways I was having a problem where my battery would die to the point where I couldn't crank the engine over within 48 hours of sitting. I got out the DMM and began pulling fuses on the dash fuse block while observing the current draw. I can't recall what my exact current draw was since this was about 3 months ago now but IIRC it was around 0.3A (300mA). I got to the last fuse (ofcourse) and when I pulled this fuse the current draw dropped to next to nothing, so I knew I had isolated the cause of the excessive current draw. This fuse was named "cigarette lighter relay". Well...... I don't smoke so I didn't care if I left this fuse out if it meant my battery wouldn't die on me in 2 days. With the fuse pulled however my factory radio does not work either. Somehow the radio is wired through that fuse. I am planning on taking another look at this problem soon since I have been driving around now for 3 months with no music!! My question is, what is the maximum or acceptable current draw you would expect to see with the ignition off?

Keith

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-24-2011, 03:49 AM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,993
Wiki Edits: 0

Thanks: 1
Thanked 119 Times in 110 Posts
I recently help a friend who had a simular problem with the batt lasting 24 hrs after a chg...... It turned out to the the factory amps killing the batt, we replaced the amps and the problem went away. Might try unplugging the radio harness and put that fuse back in, see if you still get the draw, if you have amps....... try the same, that way you would know what was draining it.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-24-2011, 04:33 AM
Registered User
 
Join Date: Aug 2006
Location: Alexandria, VA
Posts: 1,747
Wiki Edits: 0

Thanks: 4
Thanked 64 Times in 62 Posts
I recently checked the current draw on my truck, which has a Pioneer radio/CD and no other accessories, and the current draw was about 15ma with the ignition off. My analog multimeter is very old, but I think its still fairly accurate.

Bruce
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-24-2011, 05:12 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,149
Wiki Edits: 0

Thanks: 0
Thanked 101 Times in 93 Posts
parasitic current draw

I have read where 50 ma parasitic current draw is on the high end. Some examples of accessories with their current draw: Voltage regulator 1 - 2 ma, digital clock 3 - 5 ma, quartz clock 7 ma, ECM 7 - 8 ma, radio & clock 7 ma. and there are other relays and sensors that add more parasitic draw.

After a power door lock relay shorted out, the old Autolite battery was completely discharged on my '91 S10 Blazer within 24 hours. I installed a new ACDelco battery and started using a Deltron 800 ma Battery Tender and the problem was solved. I attach the battery tender every time I park the car in the garage.

Attaching the battery tender every time I park the car in the garage is probably unnecessary if I would drive the vehicle every day or two. The Blazer may sit for two weeks before being driven again so I hook up the battery tender. I have Deltran's optional battery lead attached to the positive and negative battery terminals so it is no trouble to plug in the tender.

Be aware that the ECM in the failure mode can have a high parasitic battery drain that cannot be detected in the conventional manner. When the battery is disconnected the ECM solid state circuit will not show a battery drain until the continuity is restored. Cycling the ignition switch from off to run position may cause the electrical drain to reoccur but do not do that with the amp meter installed in series with the cable and negative battery post.

Last edited by MouseFink; 08-24-2011 at 05:36 AM.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-24-2011, 07:48 AM
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Texas
Posts: 292
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
.03 is good for most, .05 is acceptable, though high, for an older car that doesn't sit for long periods of time. I believe you found your draw - the radio memory.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-25-2011, 03:39 AM
willowbilly3's Avatar
Member
 

Last journal entry: Body mods
Last photo:
Join Date: Jun 2004
Location: Black Hills, South Dakota
Age: 61
Posts: 1,208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
That draw should not run down a healthy battery. Also keep in mind that almost every fuse has numerous circuits so just pulling a fuse normally kills seveal things.
Also consider the method used to test the draw. If you have a low impedance meter in series with one of the battery cables you will get a false reading because you have circuits trying to power up and it takes way more power to power them up than it does to keep them alive but your meter doesn't pass enough currant to power them up..

Last edited by willowbilly3; 08-25-2011 at 03:44 AM.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-25-2011, 09:32 PM
Registered User
 
Join Date: Sep 2007
Location: In The Garage
Posts: 334
Wiki Edits: 0

Thanks: 3
Thanked 6 Times in 6 Posts
With the fuse back in, pull the cig lighter out and see if it's warm.
If so, you've found the drain. The cig lighter and radio are normally
on the same fuse (that's still powered with the key off), to keep
the radio memory alive. You can also unplug the cig lighter to see
if the drain's in the radio.

Auto mfgs try to keep the key-off drain around 7-15 ma, to allow
a battery to start the vehicle after 30 days. This is good for long-term
parking in airports and such...
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Another current draw problem when off. al37ford Electrical 7 07-03-2011 07:55 PM
Current draw...engine off awbazar Electrical 3 02-08-2010 12:07 PM
Question on LS1 starter current draw grobb284 Electrical 1 07-16-2009 10:23 AM
Current draw-how much is too much? al37ford Electrical 5 08-02-2005 03:17 PM
What is the normal current draw? Bryan Munday Electrical 3 01-27-2004 12:47 AM


All times are GMT -6. The time now is 01:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.