What size cable for jumper leads?

That is a good price Derek, and plenty of conductors in that cable too.

Make good Xmas presents.

Cheers, Bruce.

3m cables of 25mm2 with heavy duty clamps all for $19.95 from ABR Sidewinder.
The cable alone would cost $60 plus $20 for heavy duty spring clamps, if you could source them.
You would have to be daft to make your own....... unless you were nicking the cable & clamps! lol

RW,

Though I've answered your question below, I concur the remarks above. It would seem illogical to go down the DIY route, given the availability of Derek's product at a fraction of the cost.

Cheers

Play around with the numbers if you want longer cables or higher current.

Frank P: "Decent connections to your clamps will help keep the smoke in."

This is the key. Most cheaper sets have lousy crimping, which is what lets them down (and the smoke out) long before the cable itself causes an issue.

Surge suppression on jumper leads is a nonsense perpetrated for sales promotion. Just think about it........ Is there surge suppression on auxiliary batteries connected via solenoid relays? Is there surge suppression on starter motors? Of course not.
The low impedance of a 100ah battery, charged or flat, is about the best surge suppressor you could wish for.

With respect, it was ABR (ABR Sidewinder) mentioned above, not ARB. A significant difference in pricing structure.

As you can tell Allan, I wasn't too confident about it myself. But I had to put it up for discussion.

I wonder if it would make a difference having two systems connected. ie two alternators, one in each car etc. They would be directly earthed but still two undepoendant complete wiring, computers and sensors. This wouldn't be the case for multiple batteries in one car. What do you think?

If jump starting a 'flat' battery (call it 'A') from a good battery (call it 'B') then it is usual to have B's engine running during the jumping with its alternator contributing ... all's good. Vehicle A is not running until its engine fires-up so vehicle B alternator is contributing charge to the two batteries now in parallel. After vehicle A starts its alternator will also begin contributing charge to the two batteries. Each alternator will contribute current based on its own regulator algorithm and the voltage that each 'sees'. There is no problem with that, certainly not in the short term during the jump start operation although there may be some minor regulation confusion if the alternators remained in parallel until the batteries approached full charge.
It would be no different for "multiple batteries in one car".

If your question was in regard to 'surge suppression' with the two systems in parallel then the answer is 'no problem'. The considerations remain as for each single system as I explained before.

Its a no Brainer Buy the ABR ones

RW - Unless you're regularly jump-starting starting trucks, tractors, or earthmovers, those jumper leads of ABR's will do just fine for 98% of 4WD's.
At the price he's offering them at, you couldn't even buy a couple of clamps in Supercheap for the money - let alone 3M of cables.

Cheers, Ron.

There are some real cons around Honky. This is just one.
Fat plastic cables with minimal copper conductor is simply a fraud.

If you cannot see the conductor size at the termination then perhaps the best way to judge the size of the conductor in jumper leads is by weight. Good ones are quite heavy.

All good points, Bantam - particularly the one about ensuring the clamp jaws are coupled with a strap.

In an act of desperation, I've actually jump started a diesel Commer Knocker truck, using strands of heavy gauge fencing wire, twitched together!

I've got a set of jumper leads made up from 3.5 metres of 400 amp welder cable and the biggest and heaviest-duty booster clamps I could buy from Ashdown-Ingram - because I often have to jump start forklifts, earthmovers, and trucks with big batteries.
There's nothing I've found yet, that those leads can't handle!

The heavy duty booster clamps from Ashdown-Ingram are very conservatively rated, unlike so much of the Chinese consumer rubbish.

I actually bought 8 sets of Chinese "200 amp-rated jumper leads" from Repco last year - when they were throwing them out on special - for $6 a set!

They are bloody useless as jumper leads - but the light-duty clamps and cable are excellent for use in other light lead applications - where you don't need to carry 400 or 600 amps - and I couldn't buy the clamps and the handy light-duty cable individually, for less than $25!

Cheers, Ron.

RE: the bridging strap in the clamps, my Projecta jump starter has that, although it is more like a bridging wire.

Incidentally, when I was looking online at jumper leads, I saw a set of "Michelin" brand (as in the tyre mob) which had this feature - wait for it - Automatic Polarity Correction - meaning that even if you crossed the leads, it would still jump the car. It was a dirty great brain box in the middle of the leads, like a massive spike protector but obviously more to protect people from themselves who perhaps shouldn't be trying to jump start a car in the first place!!!

Bought some "clamps" from.... Sorry about that.

Here is the clamp, some one here said something about the pain the price of quality is soon forgotten. something like that

http://www.ebay.com.au/itm/2x-1000-AMP-PROJECTA-ALLIGATOR-CLAMPS-BATTERY-STARTER-JUMP-LEAD-CLIPS-BC1000R-B-/290822217903?pt=AU_Car_Parts_Accessories&hash=item43b65ae0af