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DirtyMech

Help! Did I Kill my Friend's Battery?

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Hey guys,

 

I need some help on a judgment call here; I may or may not owe my buddy some money.

I went with him to help diagnose a car that had been sitting for over a year, a 91 Grand

Marquis 5.0L. The car's battery hadn't been disconnected so of course it was dead. I said

"Hey, let's use the battery out of your 93 Legacy (2.2L)." So we did.

 

His car was much smaller than the Marquis and it required that I jump the Marquis with my own

car while his fully charged battery was in the Marquis. The Marquis ran for a grand total of 15

seconds, revved up high several times by my friend, before I pulled the jumper cables off,

after which the Marquis died at idle speed.

 

We assumed the car was good but just needed a new battery. After replacing his battery into

his car, he was not able to start it. So I gave him a jump. After he got home and parked, he was

not able to get the car to start again. He put the battery on a charger for a couple hours and got

it to start again, but after parking it the battery would not start the engine.

 

He thinks the battery may have died due to improper use as a testing battery for the much larger

Grand Marquis 5.0. Is this possible? I knew the battery size was different but I never imagined that

the Marquis would be able to destroy a battery in 15 seconds just because it was meant for a smaller

vehicle. But if this is true I should pay him for a replacement or at least half of one; the battery

appeared old and is almost certainly out of warranty.

 

Advice?

Edited by DirtyMech

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I don't think you killed the battery. I've started my Subarus with a lawn mower battery and a big V-8 with a GL battery. Sounds like it's just a weak battery.

 

Doug

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Sounds like a dying battery. What you did is what he would have done on a zero degree morning after the car sitting all night.

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how old is his battery?

 

he may have bad battery cables.

 

He had the option to say no to using the battery. It may have been your idea, but it was his decision.

 

Buy him a pizza and some beers - or lottery scratchers.

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Any "maintenance free" car battery three years old, or older, is suspect. Your friend's battery should have a warranty label on it, which will date it. A "maintenance free" battery older than three years is justing looking for a place to die.

Edited by The Dude

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He owes you a pizza for doing him the favor of showing him his battery was bad when the weather was nize as opposed to the middle of a blizzard :)

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I'm a little confused here. Which battery died? His out of the Marquis or yours?

 

Another item, you were able to jump start the car and it ran for 15 seconds and then died. The battery is only needed to start the car; once started, the alternator should take over to keep the car running. There could be an alternator issue here also.

 

Lastly, the car sat for a year with a discharged battery. Bad for the battery; in a discharged state, the lead plates become sulfated (coated with a sulfur compound) which renders the battery useless. For all intents and purposes, a sulfated battery is dead, will not take a charge, and the condition is not reversible.

 

It's very important to keep a battery at full charge when it is not in regular use. A fully charged battery will not allow the sulfation process to occur. A 2 Amp trickle charger on a car in storage is all that's needed to allow the battery to survive long periods of non-use.

 

Frankly, I don't feel you owe your friend anything. You offered to help, but there are still other issues here which had little or nothing to do with what you did.

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How did you connect the jump cables?

Positive to positive and

Negative to Negative

This method can fry an ECU (I have never seen it, maybe it is a myth).

 

 

It is better to connect positive to positive and

negative to the engine bracket (hook loop) of the empty car.

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How did you connect the jump cables?

Positive to positive and

Negative to Negative

This method can fry an ECU (I have never seen it, maybe it is a myth).

 

 

It is better to connect positive to positive and

negative to the engine bracket (hook loop) of the empty car.

 

No, the reason for connecting the negative jumper cable to the engine bracket is to keep any spark as far away as possible from the battery. Batteries can generate hydrogen gas which is explosive!!!!!! If your battery explodes sulphuric acid will go flying everywhere, including your eyes!!! People have been blinded and disfigured from battery explosions. A full face shield should be used when installing or jumping a battery. At the very minimum wear a pair of safety glases and maybe you'll at least save your vision.

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How did you connect the jump cables?

Positive to positive and

Negative to Negative

This method can fry an ECU (I have never seen it, maybe it is a myth).

 

 

It is better to connect positive to positive and

negative to the engine bracket (hook loop) of the empty car.

And how does connecting positive to positive and negative to negative fry the ECU? Other than connecting the cables backwards (which could certainly create some damage) I don't see the point here.

 

There's a valid point from the previous poster on connecting the last negative cable end to a good ground (engine, frame, whatever) well away from the battery itself.

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There were three batteries:

 

Mine

His

The Marquis

 

The Marquis battery was dead and set aside. His battery was used in the Marquis. Mine was used in my car while my car was running to jump his battery while it was in the Marquis

 

I had him attach the Marquis positive, then my positive and negative, then the Marquis negative when we were jumping. Not sure if that's a proper order but I heard something to that effect when I was trained. It's been a while. xP Now that I know about the Hydrogen thing (Yikes!) I will certainly have the last negative go on the chassis every time I jump a vehicle.

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His battery alone should have started the marquis all alone. It was already weak. Just because it is a v8 doesn't mean a whole lot. I have started a ford 5.0 v8 (mustang) with a 385 cca honda battery (the funny slim one meant for civics).

 

His battery was dead, you just drove the final few nails into the coffin.

 

If you value the friendship, buy him pizza and beer. If he is being a b!t@h about it and you aren't good friends, tell him to bugger off.

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And how does connecting positive to positive and negative to negative fry the ECU? Other than connecting the cables backwards (which could certainly create some damage) I don't see the point here.

 

There's a valid point from the previous poster on connecting the last negative cable end to a good ground (engine, frame, whatever) well away from the battery itself.

 

Sorry for missing punctuation. It was a question. Hydrogen gas with spark seems very more likely then frying an ECU.

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How did you connect the jump cables?

Positive to positive and

Negative to Negative

This method can fry an ECU (I have never seen it, maybe it is a myth).

 

 

It is better to connect positive to positive and

negative to the engine bracket (hook loop) of the empty car.

 

NOT A MYTH! I fried mine on my ejswap that way.

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