Jumping a dead battery

37chief · Aug 20, 2014

My wife told me she bought something for the grand daughters cars when the battery is dead. It is called Mighty Jump. About the size of a 1/2 coffee cup. I tried to tell her they are a piece of junk from China. Even though I have never tried one of the things I don't see how they can charge a dead battery. I have a hard time with jumper cables and a good battery sometimes. Anyone have any experience with these chargers from china? Stan

tomNE · Aug 20, 2014

snap on makes one that's a different shape then that, but works 100 times better then any jumpbox on the planet!

LarrySTN · Aug 20, 2014

Look at AntiGravity battery online, they are a very impressive jump start battery. They are very small. If you do much, needing jump starting, take a look at AntiGravity. I have one.

37chief · Aug 20, 2014

I forgot to mention it plugs into the cigarette lighter. Is that possible? Stan

Brendon-KS · Aug 20, 2014

Keep in mind that the cigarette lighter socket is fused at something around 15 amps and this fuse will work both ways - power going out or power coming in. So, this effectively limits the amount of power you could push into the vehicle's electrical system through the socket. About all you could do is a medium-low charge rate so you'd have to sit there for some time while the battery slowly charges. Battery chargers with a jump start setting can deliver hundreds of amps.

Allan in NE · Aug 20, 2014

Dunno Stan,

Think I'd just buy a battery.

Allan

wilson ind · Aug 20, 2014

Not to pick on you but I seem to find the boxes are really meaning a low battery as in leaving lights on while in store. This is compared to DEAD battery with little to no charge. I can see how putting under 15 amps in over say 10 min setting is parking lot would work. Battery in airport lot for a week with a drain on the system is just not going to help much.

IH2444 · Aug 20, 2014

(quoted from post at 20:01:35 08/20/14) Not to pick on you but I seem to find the boxes are really meaning a low battery as in leaving lights on while in store. This is compared to DEAD battery with little to no charge. I can see how putting under 15 amps in over say 10 min setting is parking lot would work. Battery in airport lot for a week with a drain on the system is just not going to help much.

This!

ss55 · Aug 20, 2014

How many amp-hours are actually stored in the jumper? If it's a gel battery it might have some power.

I've seen motorcycle/snowmobile jumper cables that get power from a car's cigarette lighter. Those vehicles only carry 7 or 12 amp-hr batteries. An extra 15 amps is enough to start many motorcycles and snowmobiles. Although you can usually roll-start a motorcycle or start a sled with the pull rope starter.

ss55 · Aug 20, 2014

Amazon.com sells them. User reviews say there are 20 AA batteries inside.

IH2444 · Aug 21, 2014

(quoted from post at 22:43:26 08/20/14) Amazon.com sells them. User reviews say there are 20 AA batteries inside.

AA batteries can be 2.7 AH. at 1.2 volts. So with 20 batteries 5.4 AH at about 12 volts.

mkirsch · Aug 21, 2014

It won't jump a truly DEAD battery. No way. No how.

These gizmos only work in a situation where the battery is *ALMOST* good enough to start the car, and it just needs a little help.

Jumping a dead battery

37chief

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tomNE

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LarrySTN

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37chief

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Brendon-KS

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Allan in NE

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wilson ind

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IH2444

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ss55

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ss55

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IH2444

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mkirsch

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