Author Topic: Dangerous car battery jumper cables (Read 11202 times)

fubar.gr · « **on:** February 12, 2015, 12:58:03 pm »

I bought these jumper cables really cheap.

Nice thick cables, capable of handling 1200A, according to the writing on the package

But on closer inspection:

The actual copper is less than 10% of the cable thickness!

I measured the resistance of each cable and it was 58mOhms, or 116 mOhms total for both cables. These cables can't handle more than 20 Amps tops.

electr_peter · « **Reply #1 on:** February 12, 2015, 01:26:33 pm »

Thanks for providing real example of crap/fake jumper cables. Is it possibly to deduce cable quality without destructive testing? Would any of these tests (4 wire mili-ohm reading, weight, flexibility, buoyancy) be good enough to indicate fake cables?

Topic about jumper cables was disccused recently here:https://www.eevblog.com/forum/chat/jump-starting-a-car/

EDIT: just noticed that crimp connection is a POS. Is it even a real copper (looks like aluminium)?

PeterFW · « **Reply #2 on:** February 12, 2015, 02:04:58 pm »

Quote from: electr_peter on February 12, 2015, 01:26:33 pm

EDIT: just noticed that crimp connection is a POS. Is it even a real copper (looks like aluminium)?

Could be steel, i had a few chinese cables made of steel.

Greetings,
Peter

Yago · « **Reply #3 on:** February 12, 2015, 02:25:35 pm »

Manufactured at The crazy World of Arthur Brown!

amyk · « **Reply #4 on:** February 12, 2015, 03:11:15 pm »

They'd probably survive 1.2kA for a second or two... what do you estimate is the diameter/area of the conductor?

Excavatoree · « **Reply #5 on:** February 12, 2015, 03:30:37 pm »

I'm not sure they exist outside of the US, so our non US readers might not know what I'm talking about, but the insulation looks like the stuff from which they make Circus Peanuts.

senso · « **Reply #6 on:** February 12, 2015, 03:35:49 pm »

There is no destruction involved, just pull one of the plastic sleeves that cover the wire crimp and look.
Some time ago I paid 140€ for a 400A 6m jumper cable, and man its heavy, and yes, there is nice thick cooper inside them.

The basic rule is simple, if its cheap its crap.

tszaboo · « **Reply #7 on:** February 12, 2015, 04:14:18 pm »

S owe have fake fuses, fake jumper cables and 20% of pilots who have no idea what to do when ship happens. Great.

SeanB · « **Reply #8 on:** February 12, 2015, 06:56:26 pm »

Have used those, and seen them melt as well. The insulation is foamed polyethylene with an outer skin, so it is lightweight. Melts at about 70C as well, and yes the core is copper coated steel, just like the clamps.

I reused the clamps with better cable, now the cable does not heat up at 200A but the clamps do.

fubar.gr · « **Reply #9 on:** February 13, 2015, 10:46:21 am »

The total diameter is 11.5 mm

I can't tell the actual copper diameter without taking it apart, but by the looks of it I'd say it looks like 2.5 mm2

The total cable resistance at 100+ mOhms is an order of magnitude more than the battery internal resistance and the resistance of the starter motor combined.

This means that only a third or so of the rated 12 Volts will actually reach the starter motor.

Psi · « **Reply #10 on:** February 13, 2015, 11:41:06 am »

I truly laughed out loud when i saw that picture.

richard.cs · « **Reply #11 on:** February 13, 2015, 01:50:13 pm »

Ah, "charging cables", the charge current being simply and reliably limited by the crappiness of the cables, 30 minutes later you can start the car. Also note the poor crinmping technique, the pressure on the metal-metal contact will be low because it's just folded back over the insulation.

madires · « **Reply #12 on:** February 13, 2015, 02:03:44 pm »

Quote from: fubar.gr on February 12, 2015, 12:58:03 pm

Nice thick cables, capable of handling 1200A, according to the writing on the package

I measured the resistance of each cable and it was 58mOhms, or 116 mOhms total for both cables. These cables can't handle more than 20 Amps tops.

1200 Chinese Ampere = 12.00A

dannyf · « **Reply #13 on:** February 13, 2015, 02:07:02 pm »

Quote

really cheap

High cost of low prices.

xrunner · « **Reply #14 on:** February 13, 2015, 02:11:07 pm »

Yep, that doesn't surprise me at all. There's a lot of cheap ass shit coming in from you know where. I've seen bad connections like that on smaller test leads, however, in order to see how bad the connection really is you have to cut the plastic off with a knife because its a sealed plastic connector. They are hiding a whole lot of shit from people's eyes.

That gives me an idea for a new thread - The worthless connection thread - or something like that. Look for it ...

cosmicray · « **Reply #15 on:** February 13, 2015, 02:18:00 pm »

How long would the maker of those cables last if they were sold in China. Are those intended for export only ?

SeanB · « **Reply #16 on:** February 13, 2015, 03:21:45 pm »

Export only. Remember what happenned to the makers of that melamine contaminated baby formula who sold it inside China. they became organ donors, and the family was sent the bill for this as well.

dannyf · « **Reply #17 on:** February 13, 2015, 03:29:46 pm »

Quote

How long would the maker of those cables last if they were sold in China. Are those intended for export only ?

There are countless scam artists whose business models rest on consistently scamming lots of people, one at a time.

Yes, tons of such stuff is sold in China too.

Galenbo · « **Reply #18 on:** February 16, 2015, 10:45:42 pm »

Quote from: fubar.gr on February 12, 2015, 12:58:03 pm

The actual copper is less than 10% of the cable thickness!

I measured the resistance of each cable and it was 58mOhms, or 116 mOhms total for both cables. These cables can't handle more than 20 Amps tops.

This makes them safer than the "better" ones.

Garage owners have better thicker cables, but don't put them in the hands of the ordinary guy.
Due to the bigger resistance, when short circuited, the source car isn't damaged and the sink flame is much weaker.

Sure the car won't start on these cables, but the battery will charge (with a limited current, witch is better)

CatalinaWOW · « **Reply #19 on:** February 19, 2015, 05:10:14 pm »

Just to answer the earlier question about a non-destructive test. Weigh them. Accuracy is not required. You can tell when you pick them up that they are crap. This does presume that you have calibrated at least once in your life by picking up good cables.

German_EE · « **Reply #20 on:** February 19, 2015, 09:56:32 pm »

Well, one thing is explained. I did a jump start last year and the cables melted plastic all over my front bumper, they were probably of similar quality.

jlmoon · « **Reply #21 on:** March 02, 2015, 09:21:06 pm »

I think we need to put them to a Failure Point Analysis, just to see what they can handle and how long.

dannyf · « **Reply #22 on:** March 02, 2015, 10:13:29 pm »

Quote

I did a jump start last year and the cables melted plastic all over my front bumper

High cost of low prices.

shanky887614 · « **Reply #23 on:** March 02, 2015, 10:54:04 pm »

16/25mm is much better

those cables are dangerous measuring end to end on a socket circuit is usually under 1ohm

tom66 · « **Reply #24 on:** March 02, 2015, 11:36:05 pm »

Quote from: dannyf on March 02, 2015, 10:13:29 pm

Quote
I did a jump start last year and the cables melted plastic all over my front bumper

High cost of low prices.

High cost of customers not having the knowledge to determine if a product is shit.

I have discovered Halfords (UK car parts shop) selling fake car fuses. Pack of five for £2.99. Sure, not expensive but you see a brand name and you expect that you can trust them. Nope. This importing deluge needs to be seriously looked at as there are so many counterfeit/fake/dangerous goods entering this country it's forcing legitimate suppliers out of business.


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Author Topic: Dangerous car battery jumper cables (Read 11202 times)

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