So I went to the auto parts store today for something, and asked about wire gauge for jumper cables. The guy told me that 4 gauge wire was the best, because it gives a better connection. Their cables were $25.

At Wal mart the other day, I saw some in a small package that were 10 gauge wire for under $6.

Is there really that much of a difference? The WM cables were in a small compact bag, ideal for the car kit.

Do you think the 10 cables (12ft) would work well?

My wife has a set of WM jumper cables. first time we used them they almost burned up. So yes there is a difference. 10 guage wire is about the same as what you use for house current. If you have to do much cranking they will overheat rapidly. You had better have some leather gloves to hold onto the cables.

I'm no electrician..more of Jack of all trades (and master of none) but I do have some experience in this area. Few years back I was jumpstarting my truck from the wife's car and melted the plastic on the handles. Sometime after, I was told that my cables either couldn't handle the load or the battery was bad...well I know it wasn't the battery..it started the car fine. In answer to your question, I will never depend on cheap jumper cables again. Get the smaller number wire..which is actually larger diameter(curious why they do that) and can carry the load. IMHO

As far as connection...you really just have to make sure it makes good contact, $6 alligator clips on the end of cheap wire should connect as well as the ones on the expensive..what matters is what is in the middle. IMHO

$25 may seem like a lot, but trust me...I like know that if I am jumpstarting my vehicle...I don't have to worry if they will work or not. <img src="/images/graemlins/smile.gif" alt="" />

My lady has the small jumper cables in her car. Last year, we had a cold night, and her battery did not have enough juice to start the car the next morning. The little cables worked just fine. Maybe if her battery had been completely dead, they might not have worked as well. Don't know.

BTW, a trick I learned from an OLD tow truck driver is to connect the cables and then wait a couple of minutes. He also taught me to be the only one to connect both ends, so that I know for certain that red is positive and black is negative. Also, get behind something before trying to start the dead car. I saw a car battery vent once while jump starting, spraying battery acid within about a 5-foot radius.

I always buy the longest cables I can. That way if you can't get the "jumper" car in front of the "jumpee" car the cables can reach. Think wind, cold, rain next to the cliff on the side of Hwy-1 in a very small turnout with traffic.

Dave

Of course, if everyone carried jumper cables in their cars, then we could use two sets in series. <img src="/images/graemlins/cool.gif" alt="" />

I once read somewhere that when you buy a new set of jumper cables, take some pliers and make sure the clips are tightly crimped to the cables. Probably even more important to do with very cheap cables.

Choose the cables with the biggest cross section (biggest diameter) ; those will have the least resistance and allow a good flow of current.

I once tried to start a car with a cheap set of cables : the car wouldn't start ; too much loss in those tiny cables (high amp + high cable resistance >> huge voltage loss).
When tring with sturdier cables, the car started without problem.

And yes, those bigger cables are more expensive.

As for the length : longer cables >> higher resistance. If they already have a tiny cross section >> they wont do any good and can even be dangerous...

(excerpt from Electricity 101) <img src="/images/graemlins/grin.gif" alt="" />

I keep a set of home brew 10 gauge jumper cable on my motorcycle. I'd never use that size with a car battery.

If you buy the cheap cables and they don't work, then you have to call a tow truck and sit and wait for them. Then you have to pay the bill. Then you STILL have to buy a decent set of cables.

Cut out the frustration and get something you know will work.

Do you REALLY want your wife to be stuck out somewhere on a cold, dark, windy, rainy night with $6 cables?

BTW, has anyone else noticed that a lot of the stuff you can get at WallyWorld is watered down, cheaply made and low quality EVEN when they are name brands?

Sue

The little ones are better than nothing - up to a point. But there is no comparison between the two in ampacity. If the dead vehicle is easy to turn over (small displacement 4 cyl with moderate compression ratio), the 10ga will be OK up to but not including a totally dead battery (or shorted cells or...) and they will be very iff in cold weather - meaning around +10deg-F or colder - if the dead vehicle is cold soaked.

If it's cold or the dead battery is really toast or it's a large displacement engine etc etc - you cannot get it done with the skinny wires. Figure you might be able to punch 50 amps thru 10ga wires - very briefly, and at a huge cost in terms of voltage drop. The larger cables reduce or eliminate the voltage drop AND carry vastly more amps. Even so, in extreme cold (eg -40F) it may not be possible with any spring-clamp cables - it's hard to punch several hundred amps thru those teeth. I twice had to resort to some extreme measures to jump folks at -50F or colder back in our interior Alaska days.

I won't carry anything shorter than 16' or less than 4ga, and I stick to the ones with decent low-temp insulation. Her in the MidWest, too many times I have helped folks who couldn't get it done with the cheapies - put the big cables on and the dead car lights off immediately. Biggest problem I have encountered are the protrusions on the jaws that supposedly let you sneak onto side terminal batteries - they can lead to an occasional bit of excitement in a crowded engine compartment. I have zero vehicles with side terminal batteries, so you can guess what I'd like to do with those...

Tom

I agree. I try to buy the longest set I can afford. Idealy, a 25ft. set would allow you to jump a vehicle that may be stopped in front or behind you--say on a dangerous stretch of highway.
The lower the gauge number the better. Pick a set that have both lead wires joined, so you don't have to untangle 2 wires everytime you take them out of the trunk.
Also, if you live in a region where you get cold winters, make sure the jumper cables are rated for sub-zero temperatures. In really cold weather, the cheaper cables will cease being flexible. The better cables still stay malleable within their given rating.
- Frank

Not specifically at WW, but Edie Bauer stuff is all very poor quality stuff.

Dave

Yes -- I have noticed that about Wally World. I heard that Wally World does business with its suppliers a little differently. Supposedly, each year they require their suppliers to lower the price on the goods they offer. This is so Wal-Mart can continue to lower their prices in the store.

All this cost-cutting means that companies that provide Wal-Mart with items have to look at doing it cheaper each year; e.g., overseas.

My guess is companies make two versions of their products: one version for normal sale, then another, cheaper version to offer to Wal-Mart. Not selling your product to the nation's second-largest employer (behind the Federal Government) makes you look bad and cuts into your bottom line.

Rant off. <img src="/images/graemlins/smirk.gif" alt="" />

Another case of "you get what you pay for".

Troy

Mr. Ors, definitely go with four gauge stranded wire. But more importantly, remember that a battery can explode right in your face and cause serious injury, burns and even loss of eyesight. I would strongly urge you to 1) Learn the correct sequence of connecting. 2) Wear a pair of wrap around good quality eye goggles. 3) Never assume that jumping a battery is without danger. 4) Read the witty but informative tutorial (link below).

Good luck.

http://www.misterfixit.com/jumpstrt.htm

Boone

Maybe it's already been mentioned, but could you possibly expand on the best connection sequency to minimize risk when jump starting a vehicle. Thanks in advance.

10 Gage? That's good for charging a battery - but not jumping - too much I^2R losses - aka, you hook them up, and wait, say 15-20 minutes or more while your battery charges, and then try to start the car

Personally, I think 4 gage are a bit light!! I took some old welding cables and made my own - they are ONLY 0 gage (light welding cable) - a lot more flexable than regular cables too

NON, the connection procedure is outlined in an earlier post I made but I will post the link again. It tells you about all you will need to know.

http://www.misterfixit.com/jumpstrt.htm

On the subject of dead batterys, let me offer a little tip that might be of value. Dead batterys won't take a charge if 1) the battery has gone bad, or 2) if the alternator has quit charging. If you are far from home and at the mercy of some fly by night mechanic wanting to sell you an alternator, a quick check you can make is: With the engine running, remove the ground cable from the battery. If the engine continues to run with the cable removed, the alternator is good. 2) If the engine abruptly dies when you remove the ground cable, it is likely that the alternator is bad. With this test, you will at least have some idea of what your problem is.

Hope this helps.

If you remove the battery cable on a runnign vehicle with a computer you run the risk of frying the computer. I had a service manager from a dealership inform me of that.

I have done it several times with no apparent damage but I will defer to the judgement of the service man and leave this little trick up to the judgement of the vehicle owner. Maybe some other forum member can post something on this.

It seems to me, and this is just my opinion, that if you remove the ground cable with the engine running and then turn the engine off before reconnecting it, that this would minimize the danger of damage to the computer but that is just my opinion. Of course if the alternator is bad, the engine is going to die anyway so my idea would be moot.

I have heard that just jumping one car to another can damage the electronics so what are we to believe? I know with a truly dead battery, you have to reset the clock and all the pushbuttons on the radio which is a pain. When I was growing up, cars had generators, not alternators and most were straight shift. If your battery was dead, just get someone to give you a push with the car in low or second gear and then let the clutch out when you got up your speed and the motor would start. Ah for the good old days. I guess pushing would still work with a manual transmission. <img src="/images/graemlins/smirk.gif" alt="" />

While i have done exactly what Joe has done to check an alternator, lifting the battery cable off while the engine is running can cause a spark and the battery can explode. So be careful.

The links provided above give a good explanation of how to jump start a car. But if you are driving a newer car 90's and up, read and follow the instructions in your owners manual. There can be some unusual precautions that need to be followed. I remember reading one that recomended not jump starting the car, the recomended procedure was to remove the battery and charge it. But if jump starting was deemed nessary that the drivers side door should be open for the duration of the jumt starting procedure. The reasoning was that the engine management computer was on the same curcuit as the dome light. Which hopefully would help to dampen any voltage spikes that might fry the computer which cost quite a few$$.

nice tutorial, and nice website too...thanks!

This is the thing I don't understand...in high school, I always chanted the mantra "positive to positive, negative to ground". Maybe that's why I didn't have a lot of friends <img src="/images/graemlins/blush.gif" alt="" /> <img src="/images/graemlins/grin.gif" alt="" />

Anyway, the first time my father in law helped me do a jump start, he INSISTED that the negative terminals were connected to each other too. I felt it was wrong, but he's the type of person that you can't tell anything to. So when he was around, that's the way we did it.

So my wife left her lights on one day and drained the battery. My mother in law came with her car, and I hooked up the cables, using my old mantra. I was reasonably sure the battery was okay, but let it charge for five minutes or so. It was still as dead as dead can be...let it go for another five minutes...still nothing. Then instead of grounding the negative terminal on the dead car, I put the clamp on the negative terminal...a few seconds, and the car started right up.

I don't understand it, does anyone else?

My wife wouldn't even try to jump start it...she'd call AAA <img src="/images/graemlins/grin.gif" alt="" />

But your point is well taken. Suffice it to say that in Wal Mart's effort to keep prices low, it would probably be wise to consider most products not reliable to bet your life on, eh?

Planned obsolescene...making stuff so it only lasts so long, then it becomes unusable, so you have to go buy another one. Happened with a $300 full face mask for my CPAP...didn't even last a year, while the much less expensive nasal masks last me for several years. Then someone at the medical supply shop said, "Yeah, the manufacturer only expects these to last for six months, because most insurance pays for a new one every six months"

Ah...corrupt capitalism!

I have to admit that some of their stuff looks like it would be cool. I even lingered a bit when looking at it. But then that little voice inside of me said, "It's Eddie Bauer for the sake of Pete. It's about the 'bling', not about the 'zing'! "

Although I must admit that we have Eddie Bauer car seats in our van at this moment <img src="/images/graemlins/blush.gif" alt="" />

In my defense though, we did comparative shopping and decided on it for the quality of it, and not the 'bling' <img src="/images/graemlins/wink.gif" alt="" />

Recently had a problem with the battery on my Renault Clio. A cell collasped creating a short in the battery, it died basically. Renault size the smallest battery they can expecting it to die within two years. As this one did. I didn't know this at the time. Also a funny feature of this car is the engine immobilser. When there is no volts from the battery it defaults to off and has to be reset by the garage. So even if I'd repalced the battery myself I would still be stuck as I don't know how the resetting is achieved. (note to self find this out) (second note to self, don't bother the car was stolen last night. <img src="/images/graemlins/mad.gif" alt="" />) I refused the battery offered by the garage and sourced my own, one with a high or higher Amp Hour rating. Capable of supplying the umph when you need it.

The cables I have I got from a Heavy goods vehicle store rated at something like 1200A in rush. The best set I ever had were made for me when I used to be a designer of diesel generator sets. Had to give em back when I left the company.

1- Always follow the procedure written in your vehicles owners manual.
2- Use biggest / shortest cables for max power.
3- Longer cables will offer better chance of connecting in a tough situation (contradicts no 2)
4- Look into getting a power pack, some have compressors (for flat tires) and you'll never need a 2nd vehicle to jump start your own.

".....the car was stolen last night."

Sounds like somebody did you a favor. <img src="/images/graemlins/confused.gif" alt="" /> Seriously though, I could never own a car like that.

Regards, Vince

This works, and most of us have probably done it this way or seen it done this way at some point (I've done it back as a teenager and didn't know better). The sole reason, as far as I am aware, of grounding the last clamp away from the battery instead of on the negative terminal itself is a combination of:

* The last clamp will close the circuit and may produce a spark
* Batteries can generate explosive gasses so you want to keep sparks away from the battery

By clamping +/+ and -/- terminals, you're closing the circuit and it works, but any potential spark occurs right at the battery. Most times you can get away with it, but it's that rare time that you'll regret it.

4- Look into getting a power pack, some have compressors (for flat tires) and you'll never need a 2nd vehicle to jump start your own.
**********************************************************************
Frank, let me offer a little tip about these cheap air compressors. On a flat tire, they will inflate it...........eventually, and usually gets red hot in so doing.
To assist this little fella, jack up the car to get the tire free from the pavement. It will inflate much easier and puts much less stress on the compressor by not having to raise the vehicle in the process. However, by their very nature, all air compressors heat up to some degree.

Boone

One point that is worth remembering is that you can make it a lot easier for someone to help you by always facing out of the parking spot whenever possible (backing into it or drive through). That way your battery is much closer to the car from which you are getting the jump.

Also, if you are making your own cables and all you have is smaller guage wire (say, ten guage), you can double up the wires and gain three guage sizes per doubling. Two #10 wires = a #7 and four #10 wires = a #4 guage equivalent.

I agree, the little compressors do heat up quite a bit, I'll keep in mind the jacking tip - anything to speed things up :-)

Most WM stuff is junk for the long term but one thing that has lasted 3 years is my 500 amp EverStart Jumper from Wall Mart. I am chucking this up to a random anomaly in the space time continuum.

Cowboy walks into a fancy restaurant and is told he must wear a tie by the maitre'd. So he goes outside to his truck and gets some jumper cables, ties them around his neck and walks back in. Maitre'd ponders the cowboy for a moment and decides discretion is the better part of valor. "O.K. sir, i'll let you in, but don't you start anything!"

I've never used one myself, but I have come across an air compressor that has a cooling fan built in to keep the motor and compressor cool. Supposedly, it can run for 8 hours continuously. Truck Air HD-300
Unfortunately, no built in 12 volt jump start battery on this guy.