keeping the battery disconnected
Thread Starter
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Joined: Jan 2008
Posts: 75
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keeping the battery disconnected
does it hurt anything by leaving the battery disconnected while the car is not being used? i have an 89 coupe and only drive it occastionally(once a week). the reason i ask, when i keep it connected and the car sits for a week, it drains the battery. thanks for the input.
Team Owner
Joined: May 2000
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From: Plantation Florida USAF(Retired) 1966-1990
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Try buying battery tender for the car. What a tender does it keep the battery fully charged while car is idle for weeks. Any auto store sells them. I use battery tender jr. for years with no problems.
Advanced
Joined: Dec 2006
Posts: 57
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From: Miami Florida
Should not be a problem leaving the Battery connected, unless the is something putting an unusual drain on it.
I suspect something is staying on that you don't know about. You will need to do some I Spy stuff.
I did not know that my 90 engine compartment lights were remaining on with the hood closed, disconnected the power to the lights and the dead battery problem went away.
Might be something like that for you.
Good luck
I suspect something is staying on that you don't know about. You will need to do some I Spy stuff.
I did not know that my 90 engine compartment lights were remaining on with the hood closed, disconnected the power to the lights and the dead battery problem went away.
Might be something like that for you.
Good luck
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
I recommend that you measure the leakage current, GM says it should not exceed 50 milliamps. Your battery should not be badly discharged sitting only a week if the battery is not at the end of its life! My 87 draws 27 ma. You must have much higher leakage current than the allowed 50 ma. A better solution is to fix the high leakage current circuit.
Racer
Joined: Apr 2001
Posts: 302
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From: South Haven Michigan
I have had an 89 for 9 years and have disconnected the battery when I knew I would not be driving it since I bought it. Never had any problems. I use one of the quick disconnects with the green **** so it is easy to do.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
What you don't know is that lead acid batteries self discharge up to 1% each day even disconnected. Never let a car battery sit doing nothing for long periods (4+ wks). Lead sulphate collects on the plates and a fully sulphated battery becomes a door stop and cannot be charged up. If you don't drive your car for long periods, then keep the battery charged up. The best way is with a battery tender!
Le Mans Master
Joined: Sep 2006
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
disconnect the battery
well, you lose your radio presets, your fuel mileage readout, your engine goes through relearn, etc.
I would try putting an ammeter between the alternator positive cable and the alternator positive post.
If there's a problem, you will read 1-2 amps.
other than that, pull fuses, and make a test cable tht uses the blades of a broken fuse to insert an ammeter inbetween the terminals to read amps when off.
I would try putting an ammeter between the alternator positive cable and the alternator positive post.
If there's a problem, you will read 1-2 amps.
other than that, pull fuses, and make a test cable tht uses the blades of a broken fuse to insert an ammeter inbetween the terminals to read amps when off.
Last edited by coupeguy2001; Nov 16, 2008 at 09:03 PM.
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Racer
Joined: Sep 2004
Posts: 258
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From: Coram NY
If your battery is old, it will drain if you are not using it, There is most likely nothing wrong with your car. When I purchased my 86, if I left it for 2 weeks the battery was close to dead. Replaced the battery and have had it for 2 years, left the car idle for 2 weeks + and have not an issue with it going dead.
Tom
Tom
Pro
Joined: Mar 2006
Posts: 576
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Wow. Find the battery draw. Do you really want to be taking off and installing the terminals everytime you want to use the car? On my old 86 Roadster, the car alarm was killing the battery. I gave up on the alarm, un-installed it, and the problem went away. Car stereo shops have a special talent in the area of creating phantom battery draws and ground loops. If you run the car long enough to get operating temperature, it should be fine.
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
Wow. Find the battery draw. Do you really want to be taking off and installing the terminals everytime you want to use the car? On my old 86 Roadster, the car alarm was killing the battery. I gave up on the alarm, un-installed it, and the problem went away. Car stereo shops have a special talent in the area of creating phantom battery draws and ground loops. If you run the car long enough to get operating temperature, it should be fine.
If there is not a draw the battery is old...simple like that. One week sitting is not long enough for a battery to be discharged.
Pro
Joined: Aug 2007
Posts: 623
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From: BGM NY
I took my Interstate battery (brand new) out 4 weeks ago and it is stored on a shelf in my garage where it is about 35-40 degrees during the winter. I believe the ideal temp for a stored battery is 40 degrees. Should I charge it once a month? Thanks