The battery in my car was dead dead one night. The next day, my boy friend helped to jump start my car. We ran for about 50 minutes, during which time I tried a couple times but the engine didn’t crank at all. The final solution was a new battery from AAA after 2 hours of waiting. Anyway, my question is whether the 50-min long jump-start process will do any damage to the ‘donor car’? Thanks in advance.
Was his car running the whole time?
yes. And his car is 2002 Hyundai Accent if it helps.
Well, 50 minutes is a LONG time to try and jump a car. If his battery was old, it might not help it. But I don’t think other things might be damaged. What’s the problem?
We’ve had long, long debates about this here. There seems to be no clear consensus.
Let us know if his alternator dies in the next couple of weeks.
We don’t know what the problem may be yet. His car started after the unsuccessful jump-start with no problem and drove 6 miles back home. Hope there will be no problem at all.
Sure will do.
It’ll cost the donor at least $300 for a new alternator to be installed. It isn’t a bad risk but it may not be worth it for a lot of us. If I had a 75 Impala, I would jump start everybody. Now “I don’t have cables”.
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It depends on a number of factors so the answer is maybe. I don’t think anyone here has experience with a 50 minute jump start. If there was a heavy drain during that time, it may have damaged the donor car’s charging system.
Actually, One Shouldn’t Jump Start A Car That Has A Dead (Totally Drained) Battery Without Letting The Donor Car “Charge” Its Battery, First.
Bosch warns against it because alternator damage can be the result.
The best thing to do is to charge the dead car’s battery with a battery charger.
If That’s not possible you can “charge” the battery wih a donor car. You are supposed to hook up the cables between both cars and let them sit for about half an hour with the engines off. This will not deplete the good battery. Then with the dead car’s battery now having a little charge, start the donor car and let it run for 10 or 15 minutes. It will then be much safer to try starting the “dead” car with less risk of damage.
I replace batteries sometimes long before they die. Instead of recycling a good battery by trading it in for the core charge, I keep it. (I trade an older one.) I keep it charged in the garage using a trickle charger. That’s what I grab when somebody needs a jump start. I won’t volunteer my car to be a donor, but my battery is available.
CSA
Usually there will be no harm to the donor car. You must be careful with the cables to minimize risk of damage. Hook up to “dead” battery terminals first, then the positive of the donor battery connects to the positive of the dead one. Then the negative of the dead battery is the final connection and you hook on to a “ground” on the donor vehicle (not the neg. connection on the donor battery).
As soon as the dead car starts and is running smoothly I disconnect the ground from the donor car first, then the positive, then the connections from the dead battery last. You don’t want the two cars running while connected by the jumper cables any longer than absolutely necessary. Once the dead car is running it should be able to run on its own. If it dies quickly then you have a larger problem than simply a discharged batttery. Either the alternator is shot and not charging or the battery is completely shot and won’t hold even a charge at all.
If the connections are made properly, and the cables ends never contact each other + and -, you shouldn’t hurt the donor car. But sometimes people are sloopy, sometimes the cables fall off and contact, and sometimes the dead battery overloads the battery and alternator of the donor car.
In the old days damage to the donor car was rare. In modern cars with so much electronics there can be problems due to reversing polarity. Even a short time hooked up improperly can fry the cars main computer. Power surges can occur in the jump start process and harm some electronic components. Running both cars connected together too long can harm the voltage regulators and other electronics.
I regard using jumper cables car to car as a last resort. I have a portable battery jump start pack that I keep charged an use that instead. I also have a marine battery that I will use to jump a car.
When I have to do a car to car jump start I have a flashlight and make very sure I identify all the correct terminals and a good ground prospect before I attempt hook up the cables.
Let’s K.I.S.S. here.
Ignore all the “I paid extra so I can keep a spare battery on a trickle charger in my garage so if someone needs a jumpstart in my garage I’m ready for them” stuff.
Again, let’s K.I.S.S. There was NO ELECTRICITY in your car (the capital letters are directed at the folks who replied, not you, original poster). The question boils down to “does idling a car for 50 minutes hurt it?” and the answer is NO.
For clarity we should define what is a “50 minute jump start”. If what you are saying is that you left the two cars connected for 50 min with one car running, I don’t see any problem because there probably wasn’t any current flowing due to the totally dead condition of your battery. Did you notice the jumper cables were hot? this is a clue that damage could be happening.
Now if you tried to crank your car every 30 seconds or so and never got it to do anything but groan and maybe move one revolution then abuse of both vehicles was happening.
“In the old days damage to the donor car was rare. In modern cars with so much electronics there can be problems due to reversing polarity. Even a short time hooked up improperly can fry the cars main computer. Power surges can occur in the jump start process and harm some electronic components. Running both cars connected together too long can harm the voltage regulators and other electronics.”
I saw a spot on Motor Week that addressed this issue. There is a new jumper cable that has a smart box between the two cars. Hook the cables up to any post on the donor battery, the positive on the receiver, and ground on the receiver car. Don’t worry about matching polarity. The smart box does it for you, and also prevent s voltage surges that will damge the computer. They are the Smart Jumpers from Michelin:
Caller X, You Are Incorrect. You Need To Reread The Original Question. It Was Not “does idling a car for 50 minutes hurt it ?”, As You Say It Was.
The question was “Anyway, my question is whether the 50-min long jump-start process will do any damage to the ‘donor car’?”
You ignored the fact that the original poster said “We ran for about 50 minutes, during which time I tried a couple times but the engine didn’t crank at all.”
You changed the “50-min long jump-start process” to “idling a car for 50 minutes”. There is a big difference there, particularly jumping a stone-dead car.
I am not telling you what to say or not say, just pointing out the errors in your reply.
Either way, you’re wrong with your “NO” answer. A car’s alternator was designed to maintain the charge in a battery, not charge one from a totally discharged state. An alernator being called on to do that in the vehicle that it’s installed in or one being jumped by it can overload and overheat the alternator.
Jump starts on modern cars should only be used in dire emergencies because damage can result.
Also, I’d appreciate your not telling us what advice we should give or not give on this site.
Thank you,
CSA
Once a friend asked me if I could give her a jump start, and she had already hooked up some rather sickly looking jumper cables to her car. We gave it a try but got absolutely nada. That’s when I dug out my heavy duty cables from the truck box, and her old Ford V8 fired up right away. I did notice that her cables were just a little on the warm side when I took them off.
The moral of this is that all jumper cables are not created equal, and size does matter.
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"Caller X, You Are Incorrect. You Need To Reread The Original Question. It Was Not “does idling a car for 50 minutes hurt it ?”, As You Say It Was.
The question was “Anyway, my question is whether the 50-min long jump-start process will do any damage to the ‘donor car’?”
You ignored the fact that the original poster said “We ran for about 50 minutes, during which time I tried a couple times but the engine didn’t crank at all.”
“You changed the “50-min long jump-start process” to “idling a car for 50 minutes”. There is a big difference there, particularly jumping a stone-dead car.”
Trying to start the dead car a couple times does not constitute a 50 minute jump start. What was described was 50 minutes of idling.
“I am not telling you what to say or not say, just pointing out the errors in your reply.”
No, you’re telling me what to say, and I am ignoring your guidance.
“Either way, you’re wrong with your “NO” answer. A car’s alternator was designed to maintain the charge in a battery, not charge one from a totally discharged state. An alernator being called on to do that in the vehicle that it’s installed in or one being jumped by it can overload and overheat the alternator.”
That’s exactly what an alternator does in a car that has been jump started.
“Jump starts on modern cars should only be used in dire emergencies because damage can result.”
Interesting if true.
"Also, I’d appreciate your not telling us what advice we should give or not give on this site.
Thank you,
CSA "
I never did that. What the hell is wrong with you?
i had the same experience. the cables included from the car dealer were not good, got hot, and did not help to start. range rover cables worked. later i soldered the weaker cables( with a badass solder iron ( transfo gun type ). i think they work now.
There is no clear consensus because it may or may not be fine. With all the brains in cars I got a portable jump start machine just to guarantee I would not have an issue jump starting using my cars. 12 year old thread oh my bad! Cars have changed a lot in 12 years.
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After 12 years we should know by now if it is damaged. In this day and age though, I just don’t do it. I have a battery pack just in case or a cell phone to call a truck. You can buy the electronic battery packs for $100.
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