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Jumping a Battery Correctly
My jeep was loaned to a friend when the battery went dead. He tried to jump it but he did it incorrectly. He had the positive to the positve and the negative to the negative. Doing this caused lots of heat, he burnt his fingers disconecting the cables. And a little smoke, he wasn't sure where the smoke was coming from, but the battery is completly dead. The battery didn't respond at all, before there was alittle juice left but after it was completly dead. We havn't tried jumping it again yet, was there any long term damage done, or she we just go and try to jump it the right way now?
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ANYWAY--if he did reverse the polarity and really cooked the battery, I definitely would NOT try to jump start it! I'd get a fresh battery and install that and then assess the damage.
Hard to say what might have happened, but it could be pretty bad or you could get lucky. Mostly I'd worry about things like alternator and ECM damage. It might depend upon what was operating when he did what he did.
Appreciate how much current is being drawn by the starter-usually hundreds of amps, varying by model, temperature, etc. Your trying to pump all this current through those cables, and even the small resistance they have will cause a voltage drop that is dissapated through heat.
I've seen people actually get the cables so hot that the insulation melted or caught on fire.
It sounds like the cables were connected right, I suspect that you need to charge your battery properly and test it with a load tester.
Jumper cables, which the proper term is actually booster cables, are only meant to boost a battery that has a charge level just below that necessary to operate your starter.
A small spark is normal when connecting a fully charged battery to one that is low, since current will start flowing right away into the low battery.
Some old timers used to only use one cable from positive to positive terminals then have the bumpers touch (in the days of chrome bumpers), but it's not a good idea since the quality of the connection will always be suspect.
note, warning, gasp, etc: if the dead battery is frozen, do not continue. very ugly possibilities. it must be thawed or replaced before trying again... and frankly, if you got the acid neutralized and froze the old battery, I would just take it in as a dud and get a new one. a battery that freezes, even down at 20 below Fahrenheit, is probably sulfated or shorted to death, and might pose a fire or explosion risk if you used it as a load on a good battery. remember, 650 cranking amps plus the alternator output on the good car is enough power to weld battleship plate.
If you switched the connection on the battery during charging, there is a high likelihood that you fried the diodes in the alternator and will need a new one. And there is a chance of frying the computer chip. Just give the bill to your buddy.
If the car starts and all electricaly things seem to work ok, no problem. Unless the battery goes dead again in a short time. If this happens, its time for an electrically knowledgable mechanic to get the jeep.
If the car will not start and/or it does but lots of electrical things are not working, the jumpstart might have fried the electrical system.
In either case, you should have a better idea where you need to go next if there are still problems.
About 5 years ago, I was in a serious financial crunch, so I had the habit of taking the cheap way out (buying cars at the junkyard, etc...). Well, when my '67 Catalina needed a new battery, I bought one from the junkyard for something like $15.00. Took it home, put it in the car, and it promptly died. I tried to charge it, but it just didn't seem to want to take a charge.
It had just enough juice to turn the lights on, but that was about it. Well, I'd heard somewhere that sometimes you can revive a dead battery by letting it run completely dead, and then slowly charge it back up. So I turned on the lights, and let it sit until it died completely. Let the trickle charge bring it back, and I think I ended up getting about 4 years out of that junkyard battery! That Catalina is hard on starting, too, so if it was a crappy battery, it would've gone pretty quick, I'd guess.
Don't know how or why this happened-everything was done correct. Says to me jump starting can be hazardous to your engine. Regarding exploding batteries-had one to blow up in an Olds wagon while driving-really ugly-blew battery acid all over hell. Had anyone been around it would have been really nasty. So those exploding battery stories are not myth and the eyes you save could be your own. Be careful out there.
People need to read this stuff!
No kidding! There are some very key tips in here, so I've changed the discussion title to "Jumping a Car Battery Correctly," in the hope that people will read and learn.
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