Thread: Modern Jumper Leads

Its a bit off topic, but does anyone know what felt washers are used for?

Originally Posted by Islandnomad

I'm a little confused as some people are saying use cable the thickness of your finger and others are using 1.5mm2 cable? Although I think 13mm2 was recommended but isn't available?

Here is my take on this.

The theory of using thick or thin cable is this.
If you want to connect and start almost straight away you need a thick cable as you are effectively starting from the donor's battery.

If you leave the leads connected for a few minutes you are putting surface charge into the recipients battery, in which case the disabled car would actually be starting off its own battery.

In this scenario you need much thinner leads. A bit like the cigarette to cigarette lighter jumpers that you can buy.
They rely on on a period of time to actually put some charge into the disabled battery.

If the disabled car has a good battery that is just flat and the car is normally a good starter thinner cables will suffice.

Back in the old days when sometimes a car was a bit of a bugger to start,
requiring repeated 10 plus seconds of cranking, is where thick cables are really needed.

So the reason for connecting to the chassis rather than the battery negative terminal is JUST in case of explosive gases? Or is there some electronics/ECU/computer reason?

Originally Posted by Blknight.aus

It looks like me and drive safe are going to have differing opinions on this one...

I dont recommend hooking up with the donor vehicle running.

Hi Dave, and first off, there are a number of battery manufacturers that state the same, turn the donor vehicle off while connecting the leads.

But yes, I do disagree.

This has a potential problem in that if the crippled vehicle's cranking battery is stuffed because of an internal short between cells, by connecting the leads with the donor motor off, you can pull the donor vehicle's battery down to a point where you can't start the donor vehicle, without disconnecting one of the leads.

In a worst case situation, particularly if the donor vehicle's cranking battery is not that good in the first place, you may stuff it as well.

But even if the crippled vehicle's cranking battery is stuffed because of an internal short, you will NOT harm the donor vehicle's alternator when you connect up the jumper leads while the donor vehicle's motor is running.

If you are in the middle of nowhere and there is only two vehicles, best to be safe than sorry.

Originally Posted by clubagreenie

While I have access to plenty of cable (plus a set of crimpers for eye terminals) but can't find a decent set of spring clamps for the ends. Does anyone have a recommendation on who/where has the best? Either with a good crimp or preferably a bolt for an eye terminal as I can fit these without issue (if anyone needs batt leads crimped the crimper is available to use)

1000A jobbies use a crimp and bolt. Through away the crimp that comes with it and use your own.

http://www.projecta.com.au/Products/...eryClamps.aspx

Hi again Islandnomad and as I do not make or sell jumper leads, so I have nothing to gain or loose, no matter what you buy, I just hate seeing people fork out good money on something they do not need and will not prevent something that does not happen in the first place.

Remember, that text you posted up is from someone trying to sell you something you do not need, so they will tell you anything if they think it will get them a sale.

But rather than take me at my word, as this is the age of the internet, see if you can google any genuine instances where someone has damaged their vehicle's electronics because of jump starting.

I work in this section of the industry and have done so for 40+ years now, and I am yet to see a single case where someone has had electronics damaged by a jump start that is carried out correctly. It just doesn't happen and if it did, then why is it that the vehicle manufacturers do not demand the use of "SPIKE PROTECTED" jumper leads for jump starting their vehicles.

So are you saying that if I follow your procedure above, I can just buy some of the old style jumper leads then? I take you at your word please have no doubt. I don't have much experience with electricals, that's why I asked. There seems to be misinformation out there then you can see how people get confused with entire new product ranges being released for no apparent reason. Weird isn't it then?

Its important to remember that if you are the nice person offering to give someone a jump,,
YOU do it.
dont just pass them the leads ASSUMING they will connect everything (to YOUR car) correctly,,
nothing worse than playing the Good Samaritan only to have some stranger blow the top off your brand new $300 battery---