[justplumducky]

Don't know where it came from, but this cable is from a set of automotive Booster Cables. Why is it rated for 200A if it's only 10AWG? Pic below.

Increasing the viewing size of my browser makes the info on the cable more readable. Maybe you can do the same, if needed.

 

[gregzoll]

Because it is rated for 12-16 volts DC Voltage.

 

[mpoulton]

Because jumper cables are intended only for very short duration use. It certainly isn't good for 200A continuously, just long enough to start a car. That's all it needs to withstand.

 

[justplumducky]

Because it is rated for 12-16 volts DC Voltage.

Oh yeah! I knew that! ... was just testing you :devil3:

 

[AllanJ]

If the car being jump started actually drew 200 amps through a 10 foot jumper cable set made with #10 copper wire, 4 out of the 12 volts would be dropped leaving 8 volts to start the car.

Within a few seconds the temperature of the wires would rise and the resistance would increase, increasing the voltage drop within the wires leaving even fewer volts to start the car with.

#10 copper wire -- about one ohm per thousand feet

 

[gregzoll]

It will work for Speaker Cable. If you want something good for jumper cables, go get some Welding cables and put the clips on them. You will find that you will have no issues getting a dead battery to turn the starter over.

Also most speaker cables for vehicles, you will find them also rated up to 200 Amp for #10 stranded. #8 is usually used to connect amps to the battery.

 

[Bondo]

If the car being jump started actually drew 200 amps through a 10 foot jumper cable set made with #10 copper wire, 4 out of the 12 volts would be dropped leaving 8 volts to start the car.

Within a few seconds the temperature of the wires would rise and the resistance would increase, increasing the voltage drop within the wires leaving even fewer volts to start the car with.

#10 copper wire -- about one ohm per thousand feet

Ayuh,.... Which is why I built my own jumper cables, Along time ago, outa 50' of 0ga weldin' lead, 'n parrot jaw clamps,....

The weak point is the cable lug/ bolt/ jaw interface,....

Had to take 'em apart, 'n clean 'em once,....
Keepin' 'em greasy helps,....
No air, No corrosion,...

 

[mpoulton]

If the car being jump started actually drew 200 amps through a 10 foot jumper cable set made with #10 copper wire, 4 out of the 12 volts would be dropped leaving 8 volts to start the car.

Within a few seconds the temperature of the wires would rise and the resistance would increase, increasing the voltage drop within the wires leaving even fewer volts to start the car with.

#10 copper wire -- about one ohm per thousand feet

This is a good point. Small jumper cables aren't very good for jump starting. #4 is about right for short ones that work well.

 

[carmusic]

a 10awg cable wont boost a car with a dead battery, actually ive never seen smaller than 8 ga and even with them the car is very difficult to start, good ones are 4 awg or larger

 

[TimPa]

if most car alternators put out about 80-90 amps, added to the current output of a healthy donor battery of maybe 70 a, I guess you could see 150 amps or so for a short period.

 

[GottaFixIt]

I know the insulation affects the ampacity rating of wire. For example, Cerrowire states that their #8 THHN(75'c) can carry 55 amps, while the same NM-B(60'c) can carry just 40amps- [link].

I see your wire says "(-40'c)" and I have no idea what that means, but I have a feeling that the insulation is why they state the 200amp rating. Booster cables usually have heavy insulation.

 

[AllanJ]

The relationship of insulation to ampacity has to do with dissipating heat under normal installation conditions such as in a conduit or in a wall. Some insulation materials can sustain greater temperatures before melting. Wires in free air, such as hung from utility poles, can handle more amperes compared with the same wires in a wall or other enclosed space.

The relationship of insulation to voltage has to do with electricity being able to jump through the insulation to a nearby conductor. One term used is "dielectric strength."

 

[Know A Little]

It will work for Speaker Cable. If you want something good for jumper cables, go get some Welding cables and put the clips on them. You will find that you will have no issues getting a dead battery to turn the starter over.

Also most speaker cables for vehicles, you will find them also rated up to 200 Amp for #10 stranded. #8 is usually used to connect amps to the battery.

As with any conductor size/AWG and length play into whether the cable will work for a specific job.

My jumper cables are #2AWG 20' long and will durn near start anything

 

[Oso954]

I see your wire says "(-40'c)" and I have no idea what that means,

All insulated wire and cable has a temperature range that it works within, without degradation of the insulation. In most cases we are more concerned with the upper limit of the range and that is what we are used to seeing.

I believe in this case they are giving us the lower limit of the range. You wouldn't want to pull out a set of jumper cables on a really cold day only to find the insulation snapping off because it had "frozen" stiff.

 

[dmxtothemax]

The cable may have a surge rating (short term) of 200A,
But not a continues rating.
At 200A continues it would
almost certainly melt.

 

[pomaikai]

It will work for Speaker Cable. If you want something good for jumper cables, go get some Welding cables and put the clips on them. You will find that you will have no issues getting a dead battery to turn the starter over.

Also most speaker cables for vehicles, you will find them also rated up to 200 Amp for #10 stranded. #8 is usually used to connect amps to the battery.

I wouldn't use anything under 4ga for and amp, I personally run 1/0 for amps.