Is it really necessary to replace the heavy duty battery cables on our Cummins or would the regular size gas powered truck battery cables work the same as they are also twelve volt ? I ask because on my 1990 Cummins I replaced the ground cable with a gas powered cable and everything worked fine. Just a thought.

Sorry but no... The mighty Cummins can draw upwards of 700-800 Amp in the dead of winter where a mere 100-200 amp on a gasoline engine. Huge difference. If you did cheat the system and use gasoline cables you would find your cables most likely get hot and melting away from the huge current draw in the winter time. I would suggest welding cable and solder on copper ring terminals then using top post with marine studs. Much easier to maintain.

Sorry but no... The mighty Cummins can draw upwards of 700-800 Amp in the dead of winter where a mere 100-200 amp on a gasoline engine. Huge difference. If you did cheat the system and use gasoline cables you would find your cables most likely get hot and melting away from the huge current draw in the winter time. I would suggest welding cable and solder on copper ring terminals then using top post with marine studs. Much easier to maintain.

Not to mention that the smaller cables will not carry the amps necessary to keep your starter happy. You'll see a voltage drop to the starter which lessens the life expectancy.

The load of watts will remain the same but as you choke the cable size down the voltage drop occurs like joecool mentions then the amps must go up. Hence the heat. I know these are just calculated values but it shows how everything has to remain balanced. So if you cut volts then amps must rise to meet the watt load. Always best to have overly large cables and cut the loss.

 

12.6 Volts x 700 Amp = 8,820 Watts = 10.5 Volts x 840 Amp

It's no different than sizing pipe for water lines. Too small a pipe and friction lowers gallons available and lowers psi. I think it's easier for us to understand water because it's visual. You'll only get X amount of water out of a pipe. You can up the pressure, but that increases friction and you won't gain much volume. When in doubt, always increase wire size. And when you can afford it, buy marine tinned wire.

I've seen green corrosion all the way through wire before. Not just on the ends. Marine wire is better protected.

Edited June 23, 201410 yr by joecool911

what we did on my boys truck and mine was to by some military lead clamps and cut the cables and crimped on nice connectors and put double wall adhesive shrink tube on the connector and that has worked out well. I happen to have a quality crimper but you could still save money having them crimped professionally and use the same cables.

NAPA usually carries everything to do wires for our truck correctly. I pulled my old ones and gave them to the shop and after they were done, they looked like they were factory made. Spend the extra dollars now, because the first time it gets below freezing you will not be starting the truck with smaller wires.

What do you think about these cables?  http://custombatterycables.com/application/dodge_ram.htm.   with the military end clamps.

Edited June 24, 201410 yr by Mopar1973Man
Made it a clickable link for other members

I'd look for an automotive electrical shop and have them made. Here in Oregon is ABE. Automotive Battery & Electric. Not positive, but I bet they'd be cheaper than the source above. But no evidence to support it.