Home made Jumper cable question

MrWizard wrote:
I once jumped started a car using a tow chain wrapped tight around the bumpers (his and mine) way back when cars had frame mounted steel bumpers
And one length of 10 guage wire
Because that was all that was available

But it's not what i would recommend
Forget 12ga
And forget alu unless it's 'one aught'
Get some good 2ga Copper for long cables
Or 4?6ga for normal lengthy cables

Ya, who needs jumper cables anyways? Connect bumper to bumper and dig out bumper jack and jack handle from trunk and make connection positive to positive. Man those were the days.
I came across my old timing light couple weekends ago. I remember paying extra because it also had point dwell thing on it. I still couldn't throw it away. It's a Montgomery wards brand.

Now I'm trying to find out what a "Canbus" is? Times sure have changed.

I once jumped started a car using a tow chain wrapped tight around the bumpers (his and mine) way back when cars had frame mounted steel bumpers
And one length of 10 guage wire
Because that was all that was available

But it's not what i would recommend
Forget 12ga
And forget alu unless it's 'one aught'
Get some good 2ga Copper for long cables
Or 4?6ga for normal lengthy cables

Divide the copper wire in the welding cable into halves and fasten to both halves of the clamp...lets you use smaller terminals. I use my 20' ones so often that I have a plug in the grill of my PU so I do not have to open the hood.

Op here...Thanks for all the comments. Very helpful. I'll be going by a welding supply via other shopping today. Will check out what is recommended here.

Chum lee wrote:
Look at the cables your vehicle manufacturer uses between the starter motor, the battery(ies), and the chassis ground. They use the connectors they do, the size/type cable that they do and they keep them short as possible for a very good reason. VOLTAGE DROP Starter motors are very thirsty when it comes to amps. Of course, you can't use OEM battery cable clamps on your jumper cables, that wouldn't be practical, but in general, keeping the cables as short as possible and as big (gauge) as possible will only help you when you or someone else needs a jump. Copper is king.

That withstanding, I've had very good luck using one of the many available portable "power station" type booster batteries. I bought mine at Costco for about $70.00. It saved my tail, and others, many times. I actually had my booster battery start a power stroke diesel with two dead batteries under the hood once. I couldn't believe it, but it did work. I just took about ten minutes to boost the dead batteries before starting. Keeping it fully charged all times is the key.

Chum lee

Ironic you mentioned battery boosters. As I type I have one plugged in. I plug mine around first of month and run genny in RV.

mike-s wrote:
he meant that the old ones were 16 ga X 8 conductor, or about 7 ga copper. And, he's thinking of making new ones, 12 ga X 10 conductor, or about 2 ga aluminum.

that's better, thanks.

Look at the cables your vehicle manufacturer uses between the starter motor, the battery(ies), and the chassis ground. They use the connectors they do, the size/type cable that they do and they keep them short as possible for a very good reason. VOLTAGE DROP Starter motors are very thirsty when it comes to amps. Of course, you can't use OEM battery cable clamps on your jumper cables, that wouldn't be practical, but in general, keeping the cables as short as possible and as big (gauge) as possible will only help you when you or someone else needs a jump. Copper is king.

That withstanding, I've had very good luck using one of the many available portable "power station" type booster batteries. I bought mine at Costco for about $70.00. It saved my tail, and others, many times. I actually had my booster battery start a power stroke diesel with two dead batteries under the hood once. I couldn't believe it, but it did work. I just took about ten minutes to boost the dead batteries before starting. Keeping it fully charged all times is the key.

Chum lee

2oldman wrote:
#12 is pretty light for the kind of amperage that will be carrying. Cheap cables never worked for me. Sometimes the lengths you guys go to to save a few bucks is surprising.

I think he meant that the old ones were 16 ga X 8 conductor, or about 7 ga copper. And, he's thinking of making new ones, 12 ga X 10 conductor, or about 2 ga aluminum.

But the way he put it is pretty ambiguous.

May I make a suggestion?

Your area has a welding supply store. Those stores sell neoprene (Hypalon) sheathed custom cut genuine copper conductor cables. The industry is intensely competitive so these supply shops usually offer the best deal.

Four gauge cable is great but if you have to settle for 1 AWG and pay the extra price it would be light-years better than aluminum cables which because they expose aluminum on the cut ends are utter garbage.

Your next objective will be to lay the cables parallel on the ground. You need to find out what size heat shrink tubing will fit over the paralleled cables. Proper size will just slip over the two cables.

Cut 1" lengths of the heat shrink. One strip every six inches is more than adequate. The DW's hair dryer will shrink the lengths.

The best clamps I have used have plastic tips covering the copper jaws. They are usually rated 500-amps and they are not the cheapest cable clamps around. Those mean-looking exposed silver colored clamps are steel and I probably don't need to emphasize why they are inferior.

Makeup 500 amp clamps come disassembled with the jaws, nuts and bolts in a plastic baggie.

You need to find copper lugs EXACTLY the size of the screws that attach the jaws to the plastic coated cable clamp.

While you're at it, go to eBay and buy a short length of SILICONE TEN GAUGE wire. Color does not matter but the ring terminals must fit that little clamp screw exactly.

I solder the terminals to the copper clamp pads for good reason. Then bend the strain relief pad ears over the terminals.

Cut the ten gauge silicone wire to length. The length is to BRIDGE the two pads in the same clamp together. This allows BOTH sides of the clamp to pass electricity evenly. Example: Four inches of ten AWG will pass 100 amps - no sweat.

Time to assemble: First slather on silicone dielectric grease all over the pads - every micron, both sides.

Then assemble the pads to the clamps.

You have made the finest jumper cables on the face of the earth. An heirloom for your grand kids. A 25' super long 4 gauge set will pass near full battery voltage even at 200 amperes.

Just don't leave them lying around.

#12 is pretty light for the kind of amperage that will be carrying. Cheap cables never worked for me. Sometimes the lengths you guys go to to save a few bucks is surprising.