What ampererage for jump leads?

Jonny69

Jonny69

Jonny69

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I have a new battery for the car because though I've been having some charging problems which I've sorted it goes flat in a few days of standing. I tried to jump start it to get home on Friday and melted my jump leads, yes they were smoking, and the poor member of public that tried to help was worried about his VW :D

Oh and I couldn't get it started on them even after some charging so I had to call the AA :(

Anyway, having spat half my mouthful of Special Brew out at the prices at Halfords I've gone online and found them to be a lot cheaper, as expected...

I have a choice of amperages: 200, 500, 600 or 800. I think I actually want the 800A ones but they only come in 6m long which is stupidly long for sitting in the boot and they are best part of £40, so I suppose my question is: will I be able to crank a V8 over a set of jump leads that are rated at 600A without frying them?
 
According to google a Ford F150 draws up to 200A. So I would say 600A would be fine with plenty of headroom.

Edit - Sounds like your starter has gone, when they go they draw much higher current than usual.
 
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It could be well worth looking to see if something is amiss somewhere. I only say because I've cranked over electrics-heavy 350ci fuel-injected V8s using nothing more than a diddly little set of toy town 10 quid jump leads from Halfords - in fact, I used the same set to jump the 540i yesterday as it's been sitting for ages...

Is there a fault with the charging system somewhere? It's not 6v is it, I'm sure that could cause some issues...

The ones I have in the boot look like this:

183798


Battery shouldn't go flat in a few days of standing, to say the least....is there a short somewhere or something that's permanantly live and shouldn't be? (like the coil, for example....).
 
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Whats the CCA of the battery, I would be tempted to go with that tbh. I had a set of halford 200amp jobbies and while they didn't melt, they weren't man enough to jump either my 328 or 535.

I would be tempted to get the 600n amp ones if they aren't much more expensive than the 500amp ones
 
The starter is fine, because with plenty of charge it spins over nicely. It's a later 12V starter, so deffo not 6V. New solenoid on there and the leads are all nice and chunky.

My old jump leads are literally out of their depth if they try and start a radio controlled car. Though fine to top up a slightly low battery you can't crank through them, as demonstrated :D

Edit: Oh yeah, the battery is just pure butt-shagged. I've got a cutout switch on there so it's disconnected completely when it's standing.
 
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Certainly get the 800A ones if you plan on cranking across them* with any degree of success.

Usually poor/average leads will just limit the current you get, and it'll crank slowly, not melt. :eek:




*ie, local battery providing nowt.
 
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600A will be fine. I've melted a couple, but they've both been skinny 200A sets, utterly useless. 600A will go a good few cranks on a mitsi 2.5TD L200 without getting warm, so I would imagine they'll be fine.
 
I too have completely set fire (!) to a set of 200A leads. Not sure what the current ones are but they are seriously beefy and dont get even slightly warm!
 
BigglesPiP said:
Usually poor/average leads will just limit the current you get, and it'll crank slowly, not melt. :eek:
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The wires were too hot to touch and the insulation on the connectors was smoking. I had to take them off with a rag they were that hot :D

Cool then, I think 600A will be up to the job. The 800A jobbies are just too long and they are billed as being able to jump start trucks, so maybe overkill for the back of the car :)
 
Jonny69 said:
The wires were too hot to touch and the insulation on the connectors was smoking. I had to take them off with a rag they were that hot :D
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I had a set do that, never worked the same afterwards has the handles had melted slightly.

I think that adding a spare battery and cranking @24v for 20 seconds probably didn't help though :D
 
I had a look at them but they weren't much bigger than my current ones. Plus you can get that size for about half that price online.
 
go for the biggest your budget will allow and keep a strip of emmery paper wrapped around the end in case you need to clean up a contact point.
 
We've got 2 sets... one is a flimsy set, one has almost solid cores...

The smaller of the two will overheat and smoke if you try to jump a car across them - I've had mild success in jump-starting a car approximately 5-10 minutes AFTER connecting the leads (and allowing a bit of juice to flow).

The other set, which visually look almost the same diameter cabling, but is actually stiff (much like the thick grey mains cable you place in a wall, rather than the white flexible stuff you get on an extension lead) - you connect the two batteries with that, and within 2 seconds of connecting the leads - you can start the dead car first turn of the key, as though its own battery is fully charged.


So - in other words - definitely don't skimp - get the best/longest cables you can (oh, and sometimes 6m can be really useful - if you need to span the width of two cars!)
 
Confused said:
We've got 2 sets... one is a flimsy set, one has almost solid cores...

The smaller of the two will overheat and smoke if you try to jump a car across them - I've had mild success in jump-starting a car approximately 5-10 minutes AFTER connecting the leads (and allowing a bit of juice to flow).

The other set, which visually look almost the same diameter cabling, but is actually stiff (much like the thick grey mains cable you place in a wall, rather than the white flexible stuff you get on an extension lead) - you connect the two batteries with that, and within 2 seconds of connecting the leads - you can start the dead car first turn of the key, as though its own battery is fully charged.


So - in other words - definitely don't skimp - get the best/longest cables you can (oh, and sometimes 6m can be really useful - if you need to span the width of two cars!)
Click to expand...

Length is very useful when dealing with cars where the batteries are placed on different sides, front hinged bonnets and the inability to move one of the vehicles.
 
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