I would like to mount a rear winch on a Crew Cab Long Box Pickup. With such a long wiring run between the front battery and rear winch, all calculations indicate that unless I want to run 500MCM cable the winch I chose had better be as low current draw as possible. Superwinch specs indicate their EP series winches have the lowest current draw in every weight class. However, the Winches in Hell on MoabJeeper had real world results that the EP9.0 they tested wasn't that much better on current draw than the Warn winch tested. Does anyone have experience with any of the Superwinch EP series to indicate whether they do significantly draw less current than Warn/Smittybilt/Etc or is it all Superwinch hype? Also, I don't want to go any larger than 4/0 wiring/cable to the rear winch because of cost and hassle of larger cable. Has anyone went larger than 4/0? I know I have a lot of questions for a first post but I have been very impressed with the info on this forum since finding it a short time ago. Thank You in Advance, DamMan
Superwinch; Rear Winch; Wiring Size
- Thread starter DamMan
- Start date
timmer2008
Adventurer
#1 minimum you will need to replace all the wiring 1/0 if your worried
Timmer,
Thank you for the reply. I have no problem at all going up to 1/0 cable. It was the 4/0 or bigger that had me concerned. Superwinch literature indicates that their EP series draw approx 100A less that the competitors at the same load and that sound like a good way to avoid monsterous wiring to a rear winch.
DamMan
Thank you for the reply. I have no problem at all going up to 1/0 cable. It was the 4/0 or bigger that had me concerned. Superwinch literature indicates that their EP series draw approx 100A less that the competitors at the same load and that sound like a good way to avoid monsterous wiring to a rear winch.
DamMan
JamesDowning
Explorer
You could probably run as low as 2 gauge... but the issue is voltage loss.
2 gauge probably won't get too hot over a long pull... but for every foot of wire, there's a voltage loss... call it X volts. Losing X volts over a 6 foot cable is not a big deal. However, it requires probably 40 feet to get to the rear... that's a much bigger voltage loss. In reality it will only affect your power output. If it's rated to 8k lbs, you may only get 7k or so out of it. If that is a true concern of yours, bump the wire size up to 2/0 or 4/0 or so.
By the way, you can figure out what that X is here: http://www.stealth316.com/2-wire-resistance.htm
2 gauge probably won't get too hot over a long pull... but for every foot of wire, there's a voltage loss... call it X volts. Losing X volts over a 6 foot cable is not a big deal. However, it requires probably 40 feet to get to the rear... that's a much bigger voltage loss. In reality it will only affect your power output. If it's rated to 8k lbs, you may only get 7k or so out of it. If that is a true concern of yours, bump the wire size up to 2/0 or 4/0 or so.
By the way, you can figure out what that X is here: http://www.stealth316.com/2-wire-resistance.htm
Do you have an estimate of the wire run to the back?
Voltage drop can have a serious impact on winch performance - as the voltage drops, the motor actually pulls more current, which drops the voltage further. As the current goes up, so does motor heating for the same pulling power. Not good.
I would also be skeptical of the current ratings shown by most winch manufacturers, motors do vary in efficiency, but by a few percent one way or another, not 25%.
My calculations show that a 1/0 wire, run 20ft (one way), pulling 350A (EP9.0 published spec at 9000lbs) at 12V has a voltage drop of 1.71, or 14%, which is way high. You might be fine on most pulls with lower current draw, but you'll be subjecting your motor to a lot of extra heat, and reduced power, on strong pulls. It is also going to be dissipating 600W into the wire, which will significantly heat the wiring.
If you go up to 4/0 (which has twice the circular area as 1/0), you are looking at 7% drop, and only 300W of dissipation, which is borderline, but probably acceptable, since you'll only be pulling that during full strength pulls.
I would go ahead and do it right the first time, and use 4/0 wire. Two tips for running wire that size:
- Use two wires that are half the circular area (so two 1/0s instead of one 4/0). This is very common in commercial electrical wiring. Put lugs on both, and just tie both to the same terminal. Run in parallel they will share the current equally.
- Use a very flexible wire - I love Polarwire Ultraflex (http://www.polarwire.com/), it is a 105C rated wire, it is fine stranded and very flexy, and the insulation is resistant to darn near anything. It is very common in the offgrid home wiring world. Plus, they sell by the foot on their website, and it is reasonably priced. Makes running fat wires a much less onerous process.
-Sam
Voltage drop can have a serious impact on winch performance - as the voltage drops, the motor actually pulls more current, which drops the voltage further. As the current goes up, so does motor heating for the same pulling power. Not good.
I would also be skeptical of the current ratings shown by most winch manufacturers, motors do vary in efficiency, but by a few percent one way or another, not 25%.
My calculations show that a 1/0 wire, run 20ft (one way), pulling 350A (EP9.0 published spec at 9000lbs) at 12V has a voltage drop of 1.71, or 14%, which is way high. You might be fine on most pulls with lower current draw, but you'll be subjecting your motor to a lot of extra heat, and reduced power, on strong pulls. It is also going to be dissipating 600W into the wire, which will significantly heat the wiring.
If you go up to 4/0 (which has twice the circular area as 1/0), you are looking at 7% drop, and only 300W of dissipation, which is borderline, but probably acceptable, since you'll only be pulling that during full strength pulls.
I would go ahead and do it right the first time, and use 4/0 wire. Two tips for running wire that size:
- Use two wires that are half the circular area (so two 1/0s instead of one 4/0). This is very common in commercial electrical wiring. Put lugs on both, and just tie both to the same terminal. Run in parallel they will share the current equally.
- Use a very flexible wire - I love Polarwire Ultraflex (http://www.polarwire.com/), it is a 105C rated wire, it is fine stranded and very flexy, and the insulation is resistant to darn near anything. It is very common in the offgrid home wiring world. Plus, they sell by the foot on their website, and it is reasonably priced. Makes running fat wires a much less onerous process.
-Sam
cwsqbm
Explorer
There's one way to get a lower current draw - go for a "bigger" winch. Just for example, compare a Warn M15000 with a Warn XD9000. They have the same 4.6hp motor, but the gearing is different 315:1 vs 156:1. With a 6000lb load, the M15000 draws 235 amps, will the XD9000 draws 330 amps. The trade off is line speed and therefore duration of the pull - 8.67 ft/min vs 4.43 ft/min, so M15000 pull would use more amp-hours total (although since the current draw is less, factoring in the internal resistance of the battery and resistance of the cabling might make it a wash).
bobcat charlie
Adventurer
Great thread, I'm in the middle of installing a Warn M15000 in a rear winch bumper on my Ram 2500. My local welding supply house can get 0 (1/0) welding cable and cable fittings. I'll 'probably' use the big cable. The other good option in to rear mount a 3rd battery, a large deep cycle and feed it with an isolator. I have plenty of room, it would provide a grear power source for a compressor and maybe a refrigerator, and the weight penalty is only about 50 lbs. I'm looking for recommendations. [Note: My spare tire is on a swing away carrier, so the spare cavity is available for other things!]
Thank you for all the great replies.
I was thinking 22' long truck would need as much as 25' cable one way. I think I will use a piece of rope to get a better estimate for the online calculator.
The rear bumper I want is rated for a 9000# winch so while a larger winch would likely only pull 9000# after voltage drop and layers of cable on the drum, I want to stick with a 9000# winch such as a Superwinch EP9.0 or Warn XD9000. Both have a 4.6 hp motor so Superwinch is likely wrong on their current draw specs. Just in case, I will use the higher Warn specs to size my welding cable. UltraFlex looks great as far as ability to route from front to rear of truck with least hassle.
The parallel cable idea has me thinking I could reduce voltage loss by using the truck frame as a parallel ground path by running a welding cable the full length for the ground and also connecting the winch to the rear frame and battery to the front frame with additional short cable. I don't like the idea of the frame as my only ground but it would help with voltage drop if it was a parallel path. Any ideas on this?
Again, Thank You to all for the great discussion. It definitely gives my ideas and options!
DamMan
I was thinking 22' long truck would need as much as 25' cable one way. I think I will use a piece of rope to get a better estimate for the online calculator.
The rear bumper I want is rated for a 9000# winch so while a larger winch would likely only pull 9000# after voltage drop and layers of cable on the drum, I want to stick with a 9000# winch such as a Superwinch EP9.0 or Warn XD9000. Both have a 4.6 hp motor so Superwinch is likely wrong on their current draw specs. Just in case, I will use the higher Warn specs to size my welding cable. UltraFlex looks great as far as ability to route from front to rear of truck with least hassle.
The parallel cable idea has me thinking I could reduce voltage loss by using the truck frame as a parallel ground path by running a welding cable the full length for the ground and also connecting the winch to the rear frame and battery to the front frame with additional short cable. I don't like the idea of the frame as my only ground but it would help with voltage drop if it was a parallel path. Any ideas on this?
Again, Thank You to all for the great discussion. It definitely gives my ideas and options!
DamMan
I'd be cautious about using the frame as a double-ground, in general, with electrical systems, you should avoid connecting the ground bus in multiple locations, which can cause phantom voltages on the system (ground loops). In your case it would probably not hurt anything, but wouldn't be considered a good design. If it isn't too much trouble, I'd run dedicated negative back to the battery.
-Sam
-Sam
computeruser
Explorer
I'd be careful with the use of generic welding cable. I found that the oil on K&N filters post-cleaning would drip on the insulation of the welding cable that powers my winch made the insulation soft and saggy in certain spots. Ditched the K&N, taped up the wire, and learned a lesson.