When a jumpstart goes wrong? Safety Question

Neighbor tried jumping my wife’s ‘06 Nissan Altima, we left it for 10 minutes and came back and the cables had melted through the headlight of both cars and some of the bumper. I wasn’t there but thankfully they stopped their car and were able to disconnect the cables without incident. We noticed after there had been mice living in around her engine from the mouse poop, minimum the last two weeks. What causes jumper cables to do this? Something a rodent may have chewed? Definitely an issue with my wife’s car. Our poor neighbors have a newish midsized suv. My wife has also had constant issues starting her car, even with a new battery I got a year or two ago. Anyone seen this before?

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u/jhwalk09 Dec 31 '23

That’s what I meant he insists he clamped em to the right ones, black to black red to red

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u/yorkshirepuduk Dec 31 '23

28 volts @ nearly 200 amps ye when its started take off the leads

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u/jhwalk09 Dec 31 '23

Yeah but I don’t think they ever started my wife’s car

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u/f0rcedinducti0n Dec 31 '23

Look dude, I can tell you as an engineer. Jumper cables are going to be 4 gauge or 6 gauge, and to melt them, the only way would be a short to ground. Starting the recipient car while connected will not cause this.

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u/BAS316 Dec 31 '23

Your cables may be that thick. I know mine are. I've also seen cheap ass sets for sale and in use by various people that are not. I think the worst one I've seen said 10 or 12 gauge wire.

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u/voucher420 Dec 31 '23

I could see a cheap set of jumper cables doing this.

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u/IHaveNoAlibi Dec 31 '23

If they're trying to actively start the car with them, yes.

If they're just letting the battery charge through them, no.

It seems reasonable to assume that when they left it for a few minutes, and came back to it melted, it means they weren't actively trying to start it.

1

u/voucher420 Dec 31 '23

Depends on how dead the battery was or if it was internally shorted. When you hook up two batteries together, they will transfer energy from the one with higher voltage to the one with lower voltage until they equal out. With lead acid batteries, the more they are discharged, the more current they will take. As they come closer to a full charge, they will not be able to draw as much current.

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u/YourInMySwamp Dec 31 '23

I’m not sure what mine are but I bought them from 7/11 when I was in a pinch recently and I highly doubt they’re that thick

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u/f0rcedinducti0n Dec 31 '23

12 gague wire would be a little anemic for cranking. However if you let it charge for 15 minutes and disconnected before cranking, it would work fine.

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u/BAS316 Dec 31 '23

Never said they wouldn't work. I personally wouldn't trust them though.

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u/Prize-File-3719 Dec 31 '23

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u/Ginkpirate Jan 02 '24

I have 1 gauge. Welding cables I put leads on

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u/f0rcedinducti0n Jan 02 '24

the clamps would probably melt first.

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u/Ginkpirate Jan 02 '24

What are you talking about? It's being hooked up to a battery to jump-start semi,dump trucks, heavey equipment, and cars. Claiming to be an engineerI thought you would appreciate and understand, but i feel like you wasted your money on a degree. Bigger wire less resistance. It's pretty simple. How are clamps melting?

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u/f0rcedinducti0n Jan 03 '24

What are you talking about? It's being hooked up to a battery to jump-start semi,dump trucks, heavey equipment, and cars. Claiming to be an engineerI thought you would appreciate and understand, but i feel like you wasted your money on a degree. Bigger wire less resistance. It's pretty simple. How are clamps melting?

IF YOU SHORTED A 1 GAUGE WIRE IT IS SO FUCKING THICK THAT THE ACTUAL CLAMPS WOULD PROBABLY MELT FIRST.

ENGLISH IS HARD, HUH?

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u/Ginkpirate Jan 03 '24

What the hell? I'm talking about jumper cables not shorting anything out. Reread what I originally said to you. I made my own jumper cables.......with welding cable..... your acting like a 🤡

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u/f0rcedinducti0n Jan 03 '24

What the hell? I'm talking about jumper cables not shorting anything out. Reread what I originally said to you. I made my own jumper cables.......with welding cable..... your acting like a 🤡

I see I need to slow down and explain this to you;

a 0 gauge wire has 53.5 mm² cross sectional area.

THE ACTUAL FUCKING CLAMPS YOU ATTCHED TO THEM DO NOT HAVE ANYWHERE NEAR THAT CROSS SECTIONAL AREA THROUGH THE ENTIRE CLAMP AND IS ALSO MAKING CONTACT IN A FEW DESCRITE POINTS ON THE BATTERY TERMINAL.

So, in the event of a short, the thinnest sections of the conductor (cable and clamps together) will melt first. It'll start with the alligator teeth on the clamp and them the thinnest section of the metal between there and the pivot of the clamp.

What don't you understand?

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u/Ginkpirate Jan 03 '24

You are definitely not any type of enigneer. You are officially a 🤡. I've used these jumper cables many, many times already. I'm not hooking them up to damn power plant. And you can order 1 gauge jumper cables online.......

1

u/f0rcedinducti0n Jan 03 '24

Dude, what are you not understanding.... IF YOU SHORT THEM. IF. IF YOU SHORT THEM. Like the person in this thread.

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u/Ginkpirate Jan 03 '24

Yeah, I know what you said. I already said I wasn't talking about shorting anything. So that leads me to believe we are both on the wrong page with each other. I assumed you were just saying it's wrong, and 1 gauge wire doesn't work with clamps but really you whwre still talking about if it was shorted. I'm sorry man. I apologize. I am the real 🤡 lol

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