1981 Battery Drain Issue

[Charlie P.]

I'm working on this problem, which I have searched on the archives. It is addressed, but I have a question for which I didn't see an answer. What is the lowest draw that can be expected?
While the courtesy lights are on, the draw is 2 amps. When they go off, it goes down to 0.02 amps. So there is a trace draw, which I am thinking could be for the digital clock in the ETR. Does this draw seem right for this?

Thanks,
Charlie

[Joe R.]

Re: 1981 Battery Drain Issue

I'm working on this problem, which I have searched on the archives. It is addressed, but I have a question for which I didn't see an answer. What is the lowest draw that can be expected?
While the courtesy lights are on, the draw is 2 amps. When they go off, it goes down to 0.02 amps. So there is a trace draw, which I am thinking could be for the digital clock in the ETR. Does this draw seem right for this?

Thanks,
Charlie

Charlie,

I don't know a thing about '81s, but I do know a little about electricity. 20 mA is a pretty minimal draw. I would expect a good battery would be able to start your car after it had sat for a long time. I would still put a battery minder on it just for piece of mind.

Joe

[William C.]

Re: 1981 Battery Drain Issue

I can't find a "normal" for parasitic load as it's called, but as more electronics have been loaded into cars, the static "key off" draw has steadily increased over the years. Starting in 1981 when engine management computers were required the draw saw a substantial increase over the pre-computer era to maintain the memory in the computer, so the "normal" load will vary by year. About the only way I can find to establish a "normal" would be to perform your check on several cars of the same year make and model as yours and you should get a fairly consistent "key off" drain. I used to know about what was "normal" but too many years have elapsed since I needed to know that.

[Jim T.]

Re: 1981 Battery Drain Issue

Charlie if your 1981 is having a dead battery issue in that you do not drive it much and do not have a battery tender to maintain your 81's battery, a real easy solution is to lay on the ground beside your drivers door and locate the negative battery cable bolted to the frame. Using a 5/8 inch wrench or socket remove the bolt and keep your battery from losing its charge.
My 68&70 Vette's negative battery cables are disconnected after a drive becasue I know it will be awhile before they are driven again. Depending on time disconnected I still routinly connect a charger to keep the full charge up. Battery maintenance promotes battery longevity.

[Tom B.]

Re: 1981 Battery Drain Issue

You also have a slight draw from the ECM. I keep a battery tender connected to mine and never have a problem. It used to go dead over the winter before I got the battery tender several years ago unless I disconnected the ground off of the battery. Leaning the seat forward is easier on my old bones than laying on the ground.

Tom

[Charlie P.]

Re: 1981 Battery Drain Issue

I believe the problem may be the battery itself. I've only driven the car 15 miles since I bought it four years ago, and am now starting to play with it. I may have jumped to the wrong conclusion. We'll see when I get the new battery in.
Thanks all,
Charlie