# Cleaning Battery Terminals - Car Dies



## DexterII (Jul 14, 2010)

It sounds like the battery cable ends need it, so yes, I would definitely clean them, but it also sounds like the battery is bad. I would remove the battery from the vehicle, take it to the local auto parts store or dealer, and tell them that you want it loaded tested; this is the only way to tell if th battery is bad, so no need to waste your time with a volt meter or anything else. Disconnect the negative battey cable first, and tuck the end of it back so that it will not come in contact with the negative terminal on the battery, then do likewise with the positive end. When you are ready to restore power, after the battery has been bolted back in place, connect the positive terminal first, then the negative terminal. Whenever the negative cable is connected to the negative terminal of the battery, do not allow a wrench or anything else make contact between the positive terminal of the battery and any other part of the vehicle, nor with the the negative terminal of the battery, and you should be fine.


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## DangerMouse (Jul 17, 2008)

I'd put the battery on a charger. 

If it charges ok, then I'd be looking at the alternator.

DM


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## 95025 (Nov 14, 2010)

99altrade said:


> 1) ('04 Audi) So I'm getting all sorts of warning lights, and a car that keeps dying along with it. I've boosted the car with one of those portable boosters. If this gives you any clues as to the problem: The car starts with the booster attached to battery no prob and remains on, but once I remove the booster cables the car just dies back down completely. The negative side terminal looks somewhat rusted/corroded around where it connects to the battery. Does it make sense that cleaning that terminal would solve the problem or doesn't sound like that?
> 
> 2) So I have general instructions to clean the terminals with baking powder, water, brush. However I'm always nervous around all things electrical. Can someone explain to me why I shouldn't be nervous touching around there, or what precautions to take while cleaning the terminals/battery to not get electrocuted .
> 
> Thanks .


First of all, a 12-volt car battery never electrocuted anybody. You can relax, though you'll always want to err on the side of safety. 

That said, I'm going to guess - with almost absolute certainty - that it's just time to replace your battery. If the car won't run that long, pull the battery and take it to your local auto parts store. Have them test the battery. You'll probably need a new one. So leave your old core there, bring the new battery home, and you're good to go.

If you want to clean your battery cable ends, remove them from the battery, and stick them in a cup of Coke while you're at the parts store. (When I say "Coke" I'm referring to the stuff that comes in a red can and you DRINK.  )


Good luck!


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## 99altrade (Nov 18, 2010)

Thanks for all the replies.

So first, to those who suggested that it might be time to replace the battery. I got this new battery around 10 months ago. It's still possible that it needs to be replaced given that?

Regarding the 12v electrocuting, just have never done anything relating to car battery's other than jumping cars, and am not familiar with electrical....it's a bit scary battery! lol

To someone who asked, yes it takes a charge in that I attach booster cables to battery and power other end. I am then able to start the dead car, and it remains on until I remove booster cables at which point it just dies. Is it still possible alternator or does that mean dead battery?

Thanks again guys.


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## DangerMouse (Jul 17, 2008)

Sure sounds like a dead battery to me then. If the battery were any good, it'd stay running, right?


Take it to the store as suggested by DexterII.

DM


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## 95025 (Nov 14, 2010)

99altrade said:


> Thanks for all the replies.
> 
> So first, to those who suggested that it might be time to replace the battery. I got this new battery around 10 months ago. It's still possible that it needs to be replaced given that?
> 
> ...


If the car dies immediately after you pull the cables, you've got a battery problem. It's possible that the terminals are corroded, but they probably wouldn't cause that problem. It takes very little electricity to run a car, once it's started.

Take the battery back to where you got it. Yes, it entirely possible for a battery to punk out within a year. It's a fluke, and shouldn't happen, but once in awhile it does. Hopefully they'll replace it for free (assuming you have the receipt). If not for free, they certainly should pro-rate the cost of a replacement.


If that doesn't work, you're always welcome to just GIVE the car to me. I think I could get by with it.


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## 99altrade (Nov 18, 2010)

If it's relevant, and adds clues, prior to not starting at all it was drivable. This all started with electronic power control (epc) + engine light, and car would suddenly lose power while driving, luckily able to pull over while still rolling. Happened couple times during a roundabout and back home, then once in driveway it wouldn't start again.

Oh, and ye, I'm certain you could get by with it! It's an amazing car (besides for this issue  - '04 Audi S4. 350hp + quattro for winter. Monster in great condition otherwise.



DrHicks said:


> If the car dies immediately after you pull the cables, you've got a battery problem. It's possible that the terminals are corroded, but they probably wouldn't cause that problem. It takes very little electricity to run a car, once it's started.
> 
> Take the battery back to where you got it. Yes, it entirely possible for a battery to punk out within a year. It's a fluke, and shouldn't happen, but once in awhile it does. Hopefully they'll replace it for free (assuming you have the receipt). If not for free, they certainly should pro-rate the cost of a replacement.
> 
> If that doesn't work, you're always welcome to just GIVE the car to me. I think I could get by with it.


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## 95025 (Nov 14, 2010)

99altrade said:


> If it's relevant, and adds clues, prior to not starting at all it was drivable. This all started with electronic power control (epc) + engine light, and car would suddenly lose power while driving, luckily able to pull over while still rolling. Happened couple times during a roundabout and back home, then once in driveway it wouldn't start again.
> 
> Oh, and ye, I'm certain you could get by with it! It's an amazing car (besides for this issue  - '04 Audi S4. 350hp + quattro for winter. Monster in great condition otherwise.


Okay... Forget this whole battery issue. I'm coming over with the tow dolly! 


Seriously though, it sounds to me like a battery issue. Once in a great while one of the "plates" in the battery will break & cause erratic power changes. Sometimes a battery just dies. Not often, but it does happen.

Here's hoping your problem is just the battery, and you're back in business!


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## 99altrade (Nov 18, 2010)

Alrighty then. Thanks for the replies guys, and Doc. Once I find some time I will try some of this advice, and will report back.


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## nap (Dec 4, 2007)

> =DrHicks;629880]First of all, a 12-volt car battery never electrocuted anybody. You can relax, though you'll always want to err on the side of safety.


electricuted/ no but I do know a guy that lost a finger from shorting out his wedding ring (with the help of a wrench) from the hot terminal to a ground.

I would clean the terminals first. (and that means removing the cables from the battery and cleaning the battery terminal and the cable end) If there is enough corrosion, your battery could be absolutely fine but due to the poor connection, it cannot transfer power from it or receive it from the charging system. If this is the original battery is may very well be bad though. If it has been replaced before, I wouldn't jump to that conclusion.

so, clean the terminals. If you have a charger, charge the battery. Then see what happens. If you don't have a charger, use the jumper device and see what happens when you remove it.


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## daveb1 (Jan 15, 2010)

I'd clean up the cable ends and then put the battery on a slow charger overnight. Today's alternators don't last too long when used for charging dead batteries.


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## nap (Dec 4, 2007)

daveb1 said:


> I'd clean up the cable ends and then put the battery on a slow charger overnight. Today's alternators don't last too long when used for charging dead batteries.


that is a very good point. The last couple of alternators I have replaced said, very clearly, do not install them with a discharged battery as it will overheat the alternator. It voided the warranty. Not sure how they would actually know but the point is, apparently it has been enough of a problem they say not to do it.


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## rusty baker (Feb 13, 2009)

Could very well be the alternator. Once a car is started, the alternator will provide enough power to run it even with a dead battery. Haven't tried with newer vehicles, but in the past I have removed a good battery while a car was running and replaced it with one that was discharged and the vehicle kept running even while there was no battery in it.


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## nap (Dec 4, 2007)

rusty baker said:


> Could very well be the alternator. Once a car is started, the alternator will provide enough power to run it even with a dead battery. Haven't tried with newer vehicles, but in the past I have removed a good battery while a car was running and replaced it with one that was discharged and the vehicle kept running even while there was no battery in it.


don't do that with newer cars. You can cause damage to electronics in the car.


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## rusty baker (Feb 13, 2009)

nap said:


> don't do that with newer cars. You can cause damage to electronics in the car.


That's why I do floor covering. My days as a certifed Toyota mechanic was long ago.


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## ukrkoz (Dec 31, 2010)

sorry i did not read through all the posts...

properly working alternator should maintain powertrain fully running without battery even connected. i had it tested several times and it does run with cables off the battery.
battery is nothing more than a power storage in case of emergencies or supply, exceeding what alternator produces. also, it works as a back up power supply for all the devices that run when alternator is producing no energy. on non-hybrid cars, it also provides power for starter.

of course you have dead battery if your alternator is not producing enough power.

also, speaking from my very little experience with German vehicles, as i stay away from them, they have some sort of electronics filled box on top of battery, right? my daughter in-law's jetta does. they had similar problem 2 yrs ago, and culprit was one of the pieces in that device. it was bridging battery terminals. whatever it is.


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## rusty baker (Feb 13, 2009)

ukrkoz said:


> sorry i did not read through all the posts...
> 
> properly working alternator should maintain powertrain fully running without battery even connected. i had it tested several times and it does run with cables off the battery.
> battery is nothing more than a power storage in case of emergencies or supply, exceeding what alternator produces. also, it works as a back up power supply for all the devices that run when alternator is producing no energy. on non-hybrid cars, it also provides power for starter.
> ...


That's what I said, but some were convinced that I was wrong.


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## nap (Dec 4, 2007)

rusty baker said:


> That's what I said, but some were convinced that I was wrong.


who said you were wrong about what?

I said pulling the battery out of circuit while the vehicle is running can cause damage to electronics...and it can. Suggesting anybody pull the battery cable from the battery to check if the alternator is putting out any power is a good way to throw away money. I learned it from experience in a 1988 Ford. After I screwed up a $100 part (in the mid '90's) I did some investigation and subsequently learned that you should never do that. You can cause damage to electronic parts.


The battery does more than store power for starting. It acts as a filter for the unsteady and somewhat dirty power you get from an alternator. That unsteady and dirty power can kill electronics. 



Then, if the alternator is already bad, what kind of power do you think that is going to feed into all of the electronic gizmos?

In a couple minutes of looking around to confirm I wasn't crazy, I found a guy telling about a bunch of alternators from some boats that were apparently damaged when the boat operators turned off the battery disconnect with the engine still running. 

So, take it from somebody that learned the hard way; you should not pull the battery out of circuit. If you don't want to believe me, start doing some serious reading. There is plenty of information on the internet from qualified sources telling you to not do that.


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## 99altrade (Nov 18, 2010)

*...*

Thanks for all the replies and discussion. It is educational for me...thanks.

So I haven't gotten a chance yet to take the car to the shop (just driving my other, and this one needs a tow). Though, what I'm thinking of doing at this point to just clear things up and know I'm good to go (though will still take to shop, check VAG/Audi codes, and see what he says), is to put in new battery and alternator - but not happy about the cost. 

I'm told that it's fine to buy a used alternator. What are your guys opinions on that? I'm not into the idea. May cost 100 instead of 400. I like to save, but not at the expense of doing it right.

Thanks.


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## nap (Dec 4, 2007)

have the alternator tested before replacing. Autozone and Advance Auto both do it for free and I think both can do a carry in alternator.

used alternators; I really tend to shy away from used parts unless there is a decent warranty (or I accept there is no warranty and that fits my needs at the moment). Last thing I want to do is change my old broken alternator for somebody else's old broken alternator. If you can get some sort of warranty that is actually one that will be honored, I don't see a problem with a used part.


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## 95025 (Nov 14, 2010)

99altrade said:


> Thanks for all the replies and discussion. It is educational for me...thanks.
> 
> So I haven't gotten a chance yet to take the car to the shop (just driving my other, and this one needs a tow). Though, what I'm thinking of doing at this point to just clear things up and know I'm good to go (though will still take to shop, check VAG/Audi codes, and see what he says), is to put in new battery and alternator - but not happy about the cost.
> 
> ...


First of all, why replace the alternator if it's okay? A good auto parts store can easily check it for you. And I wouldn't go used. A rebuilt Bosch, _with lifetime warranty_, at OReilly's is about $200.

That said, if it was my car I'd take the battery in and have it tested. Honestly, everything you have described leads me to believe your problem is the battery. 

Start simple, start cheap. Work your way up from there, if need be.


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