# battery dying



## canadaclub (Oct 19, 2006)

Having a heck of a week here Can anyone tell me the best way to isolate whatever is killing my battery overnight?

No lights left on but every morning its dead. Battery is only 6 months old.


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## Thurman (Feb 9, 2009)

Need more info on the particular vehicle, why? IF it is a GM vehicle 2007 model year of after, there were a lot of BCM's (body control modules) which would not shut down as they should have. This would create a "parasitic" draw in the electrical system and kill a battery in about six hours. The dealer's have the TSB's (Technical Service Bulletins) on this and instructions on how to perform the test over a 24 hr. period. Ask me how I know all of this. David


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## canadaclub (Oct 19, 2006)

Thanks for the reply David:thumbsup: Unfortunately I'm not rich enough to afford that vehicle:laughing: Mine is a 98 Ford Windstar


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## Gary in WA (Mar 11, 2009)

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

Be safe, Gary


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## rustyjames (Jul 20, 2008)

Quite often, if it's not something such as a light on or something like that, it'll be the altenator.


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## Yoyizit (Jul 11, 2008)

For a 60 A-h battery to die in 8 hours you're looking for at least a 7A drain. That much current has to make heat, light or noise.
Normal parasitic drain might be less than 100 mA.


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## canadaclub (Oct 19, 2006)

Since I bought the vehicle, used, the chime sets off like I still have the keys in the ignition...no big deal. I noticed a clicking sound from the fuse panel, even under low power. I took out the relay which was labelled auto lights...even though I dont have have auto lights...hoping that was the problem. Still a dead battery. If I put an amp meter on, what reading should I expect to see? I suppose I will have to pull fuses one by one.

Since all of my friend is working, is it possible to do an Amp check myself? I thought that the use of booster cables may work, being 4 conductor, but has anyone tried this?


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## canadaclub (Oct 19, 2006)

Sorry Gary, I missed your post,,I will try that tomorrow and thanks


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## Yoyizit (Jul 11, 2008)

canadaclub said:


> Since I bought the vehicle, used,


This reminds of something. 
Let's say the regulator was bad and the car's electronics were exposed to 17 vdc for months on end. As the battery electrolyte boiled out the previous owners just replaced the batteries, thinking they were defective.
If this is true, the car is creamed even though everything looks fine.

It could also be that your battery is low in charge. With the engine running at a fast idle and all acc. off you should be seeing at least 13.3 vdc on your battery. In the winter it could go to 15.5 vdc.


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## canadaclub (Oct 19, 2006)

But it runs fine after a boost..just loses charge over night


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## Yoyizit (Jul 11, 2008)

canadaclub said:


> But it runs fine after a boost..just loses charge over night


A boost doesn't fully charge it.

I ran an experiment back when I "was a kid": I purposely left on the headlights. 
After 3 hours the headlights were still bright but the car wouldn't crank. 
After 4 hours all was dead. 

So I jumped it and went for a drive with the first wife and kids to recharge. Unfortunately I somehow stalled the car at the end of the block [it had auto transmission]. 
To my utter surprise it cranked as if the battery were fully charged but once running the ammeter was still way over on the charge side and stayed that way for almost four hours.

Welcome to "surface charge".

[My ex got that car].

[This forum is more fun when I'm half drunk].


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## canadaclub (Oct 19, 2006)

I always turn headlights on after a boost to supply load, something I learned years ago and a good spin on the highway helps as opposed to just idle ( which I hear can do more damage to the battery?)


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## Yoyizit (Jul 11, 2008)

Since your problem is reproducible rather than intermittent, with a DVM/clamp-on ammeter and with pulling fuses you should be able to find it.

Too bad you don't live near Rockville, MD. I cannot resist a challenge.


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## Thurman (Feb 9, 2009)

A '98 Ford Windstar is just fine. Hmmm, Windstar, van, sliding door on passenger side? I work for a friends auto parts store part-time (when needed, and often), I do go into many shops and hear stories at the store. Seems like somewhere in the back of my feeble mind there was a problem with a connection for interior lighting on Ford Windstar's and a similar problem with Chrysler vans some years back. Something to do with a "pin connector" where the door closes not making good contact and leaving the computer to think the door was not actually shut correctly. This _MAY_ be a problem leading to a "Parasitic draw" on the electrical system. I would to the test Gary recommended-first. I would also highly recommend, if you have not done so, to purchase a "Haynes" or "Chilton" manual for your vehicle. NO, I don't make money off of these, they are valuable for anyone who owns a vehicle that does not have a warranty-IMO. David


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## canadaclub (Oct 19, 2006)

Got a boost this morning and let it run for about 45 minutes. Then I went for a long drive, about an hour.

I put a meter between the neg side of the battery and the cable. It read 0 but flickered off and on with 1 miilliamp. I then did a voltage reading and got 12.97 vdc. I waited an hour and it read 12.54. Was enough to turn over the engine once but not enough to start. At least I had enough power to shut the window because its supposed to rain. 

So, next I disconnect the neg terminal again and waited for 2 hours. Voltage now is 11.99vdc. I guess the battery is shot. Sheesh, I've only had it 6 months.

I also disconnected the red lead while the car was running and it continued to run so I assume the alternator works fine.

Sure appreciate the help folks. Tomorrow I'll take it in and get a replacement.


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## rustyjames (Jul 20, 2008)

canadaclub said:


> Got a boost this morning and let it run for about 45 minutes. Then I went for a long drive, about an hour.
> 
> I put a meter between the neg side of the battery and the cable. It read 0 but flickered off and on with 1 miilliamp. I then did a voltage reading and got 12.97 vdc. I waited an hour and it read 12.54. Was enough to turn over the engine once but not enough to start. At least I had enough power to shut the window because its supposed to rain.
> 
> ...


That's not a good way to test your charging system, and it doesn't indicate that the altenator that is not discharging the battery.


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## canadaclub (Oct 19, 2006)

Hmmm...can you expand on that?


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## Yoyizit (Jul 11, 2008)

I would not conclude that your battery is shot. 

Do not disconnect the battery when the car is running.


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## rustyjames (Jul 20, 2008)

canadaclub said:


> Hmmm...can you expand on that?


A bad diaode will allow it to charge, but drain the battery.


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## rusty baker (Feb 13, 2009)

With the car turned off and everything on the car turned off, underhood light, trunk light, dome light, etc. Disconnect the hot cable, if it sparks, you have a short.


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## canadaclub (Oct 19, 2006)

Well, picked up a new battery today, swapped it out, and works like a charm. Thanks again all for the help:thumbsup:


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## Yoyizit (Jul 11, 2008)

So the old battery was sulphated? 
Coulda' fooled me. Usually these crank the engine fast at first and then rapidly slow.


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## cowboy dan (Apr 11, 2010)

canadaclub said:


> Well, picked up a new battery today, swapped it out, and works like a charm. Thanks again all for the help:thumbsup:


with the new battery installed how does it charge now? i read that it was charging at 12.5v. is it still charging at 12.5? if it is your new battery will soon die. you ignition requires 12 by itself. you should have 14v charge and more on cold days. no less than 13.5 in order to use your accesories without putting too much load on the battery


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## rusty baker (Feb 13, 2009)

A voltmeter won't read correctly on a bad battery, so he original readings don't matter.


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## Yoyizit (Jul 11, 2008)

rusty baker said:


> A voltmeter won't read correctly on a bad battery, so he original readings don't matter.


Say what?


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## canadaclub (Oct 19, 2006)

Hmmm.I put a VM on a battery and you say its no good if its bad battery? Interesting. Then how would I know its a bad battery since the VM can't read voltage on a bad battery??


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## canadaclub (Oct 19, 2006)

cowboy dan said:


> with the new battery installed how does it charge now? i read that it was charging at 12.5v. is it still charging at 12.5? if it is your new battery will soon die. you ignition requires 12 by itself. you should have 14v charge and more on cold days. no less than 13.5 in order to use your accesories without putting too much load on the battery


The new battery shows 14.3 volts. Starts like a charm. I can't tell how its charging because I only have an idiot light and no gauge.


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## Yoyizit (Jul 11, 2008)

canadaclub said:


> The new battery shows 14.3 volts.


Then it's being charged. Anything above 12.8 means some current is flowing into the battery.

If the voltage stays at this value with the headlights and accessories being switched on and off then the regulator is also working.

You can also make an AC reading on your battery. Excessive AC ripple voltage means a problem in your alternator or high internal impedance in your battery. 
The problem is, I don't know pass/fail limits or test conditions for this ripple voltage.


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## rusty baker (Feb 13, 2009)

If you put a voltmeter on a battery in a running vehicle and it reads less than 14, It can be either a low battery or a faulty charging system. So it means nothing. If you know the battery is fully charged, and it reads less than 14, it is the charging system.


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