Removable front winch mounting

[DaveInDenver]

So why does Warn sell these?
So no bueno?

Quick Connect Power Cable, 24' - 32966

This 24" Quick Connect Winch Power Cable is used for rear mounting of portable winch and connects to battery and includes power interrupt kit

www.warn.com

Anderson SB175 using a 1/0 AWG terminal is rated to 280 amps in a wire-to-wire connection per UL. The CSA rating is 175 amp rating, as is the UL for a 3-pole configuration.

These ratings are determined by duration and ambient temperature. Anderson has to assume an indefinite length of time in an ambient environment of 25°C with a maximum of 30°C temperature rise (per CSA) or 105°C absolute temperature (per UL).

So the connector, per UL, with 1/0 terminals can carry 280 amps as long as you'd like at 25°C. IOW, these connectors are rated the same as the cable itself. A 1/0 AWG 105°C cable is usually given an allowable current of 285 amps. Any other cable and terminal size would follow the same pattern of the SB175 and cable sharing the same ratings.

A winch in normal use can't draw 480 amps for very long without itself overheating (given by duty cycle) or flatting the battery so the cable and connectors aren't typically stressed. The engineer can then decide if the duration is sufficiently short that temperature rise won't be a problem with higher currents or that average current meets the requirements.

 

[john61ct]

Better to go to a 24V winch if you need to pull for long

there are "serial to parallel" switches so you don't need to carry & maintain a dedicated 24V bank

 

[mep1811]

I had a winch mounted on the front receiver hitch. I never took it off much too heavy to move around. I never hit it off-road. I put a post at the end so I knew where the winch was when parking. A cover kept it clean. Thankfully I only used it twice.

 

[billiebob]

soo many reasons to go with the receiver mount.

The ability to leave it in the garage 10 months of the year.
Mount it front or rear.... often the easy way to get unstuck is reverse.
One winch?? Five guys with receiver mounts.

The only negative I see is the flex, stress in that single point load on the receiver. A bolt on winch to a welded bumper holds everything in tight alignment. There is zero flex. When winding cable under load to either end of the drum the single, loose, receiver winch mount twists creating an angle and causing the cable to bunch and pile up at the end of the drum when under load. This can happen on a solid bolted mount too but eliminating the flex in the receiver reduces that factor.

I really like the convenience of the winch permanently mounted but there are advantages to the receiver mount if you will never need 100% of the winching capability/capacity.

PS, I have never used my winch to get "unstuck" I've used it to get up an icy driveway and move things like logs. I'm likely the ideal candidate for a receiver mount.

 

[RoyJ]

So why does Warn sell these?




So no bueno?

Quick Connect Power Cable, 24' - 32966

This 24" Quick Connect Winch Power Cable is used for rear mounting of portable winch and connects to battery and includes power interrupt kit

www.warn.com

Will the winch turn? For sure. Close to max performance? I highly doubt it's close.

First the cable looks thin, I'd say 4 gauge, or 2 gauge max. For a 24' run there'll be serious voltage drop. That solenoid also looks way too small, I'd hard wire it.

I found the specs on the Anderson SB175 connector:



With a 4 gauge cable, you're pretty much at thermal limit at 175 amps. With 2 gauge, you get 200 amps.

On the Warn amp charts, 175 amp gets you less than 2000 lbs of line pull. 200 amp gets roughly 2200 lbs. Is that enough? That's a personal choice you'll have to make.

Why does Warn sell the kit? Because when we're really stuck and need to be winched out backwards, a 2000 lbs line pull becomes 4000 lbs with a snatch block, and that's better than nothing!

 

[DaveInDenver]

Will the winch turn? For sure. Close to max performance? I highly doubt it's close.

First the cable looks thin, I'd say 4 gauge, or 2 gauge max. For a 24' run there'll be serious voltage drop. That solenoid also looks way too small, I'd hard wire it.

I found the specs on the Anderson SB175 connector:

View attachment 621221

With a 4 gauge cable, you're pretty much at thermal limit at 175 amps. With 2 gauge, you get 200 amps.

On the Warn amp charts, 175 amp gets you less than 2000 lbs of line pull. 200 amp gets roughly 2200 lbs. Is that enough? That's a personal choice you'll have to make.

Why does Warn sell the kit? Because when we're really stuck and need to be winched out backwards, a 2000 lbs line pull becomes 4000 lbs with a snatch block, and that's better than nothing!

You'll find that with 4 AWG the SB175 is not your limitation. The SB175 data sheet references that their ratings are based on using wire with 105°C insulation.

Keep in mind all of these charts assume indefinite lengths of time and that's not necessarily a true application assumption. Warn in this case is making an average heating assumption based on winch average load and duty cycle.




ABYC Ampacity Rating Table at 30°C

• For bundles of 4 to 6 conductors multiply by 0.857
• For bundles of 7 to 24 conductors multiply by 0.714
• For bundles of 25 or more, conductors multiply by 0.571

SAE conductors are smaller than equivalent AWG by 5%–12% with current capacity typically less by 7%.
ISO Ratings for metric wire are slightly less than these values derived from ABYC VI-A ratings.

Wires counted in bundles need not include:

1. Wires carrying intermittent currents no more than rating per VI-A and for less than one minute per mm of diameter‚ and not repeating more often than a delay of 5 times active duration.
2. Wires carrying load currents at less than 50% of the wire rating per table VI-B.

 

[RoyJ]

You'll find that with 4 AWG the SB175 is not your limitation. The SB175 data sheet references that their ratings are based on using wire with 105°C insulation.

I agree, but the SB 175 will hit some ampacity limit around 250 amp, because if you look at the SB350 spec:

https://www.andersonpower.com/us/en/resources/SBseriesResourcesPage.html

The same 1/0 cable hits thermal limit @ 250 amp with the SB175, but 300 amp with the SB350

Either way, looks like I was was optimistic, if we go by voltage drop chart you posted, a 4 gauge cable hits 10% voltage drop @ 30' at only 100amp. That won't even do a 1000lbs line pull. We'll need a 4/0 cable to take 450 amps @ 105deg (Warn 8274 full line pull).

BUT, even with an SB350 connector, we need to step up to a 300MCM cable to stay within connector thermal limit. Conclusion - there is no reasonable quick connect kit that can power a rear winch at full line pull, short of mounting a set of heavy duty rear aux batteries (what I have on my truck).

 

[RoyJ]

BTW, just realized you said the ampacity chart is based on indefinite thermal limit. Let's try to find the voltage drop limit then.

Let's assume 10% voltage drop (any more the winch would loose too much line pull). Using 12v nominal and 450 amp as our current:

R = 12/450 x 1000' / 24' = 0.100 ohm/1000'

On the table, 1/0 does 0.102 ohm/1000', good enough. We still need an SB350 connector though, no way the SB175 can take 450 amps! My own 1/0 run is only 10', so I'm at 4.16% voltage drop.

 

[Peter_n_Margaret]

Don't forget that the start voltage with an alternator running is closer to 14.5V.
Cheers,
Peter
OKA196 motorhome

 

[DaveInDenver]

I agree, but the SB 175 will hit some ampacity limit around 250 amp, because if you look at the SB350 spec:

https://www.andersonpower.com/us/en/resources/SBseriesResourcesPage.html

The same 1/0 cable hits thermal limit @ 250 amp with the SB175, but 300 amp with the SB350

Either way, looks like I was was optimistic, if we go by voltage drop chart you posted, a 4 gauge cable hits 10% voltage drop @ 30' at only 100amp. That won't even do a 1000lbs line pull. We'll need a 4/0 cable to take 450 amps @ 105deg (Warn 8274 full line pull).

BUT, even with an SB350 connector, we need to step up to a 300MCM cable to stay within connector thermal limit. Conclusion - there is no reasonable quick connect kit that can power a rear winch at full line pull, short of mounting a set of heavy duty rear aux batteries (what I have on my truck).

Agreed completely that the SB350 is a better choice for the task. For a 4 AWG, though, the cable itself is insufficient rather than the connector. At >2 AWG things are different, even more so at 1/0 AWG. At 2 AWG the SB175 is marginal in the application and if you're running 1/0 AWG it's clear SB350 is the better choice.

My point is average heating doesn't have to be as harsh as assuming an indefinite 450 amps. Most of us never ask for our winch's full power continuously for several minutes, which is the implied use case by using 450 amps to determine wire size.

Those wire charts have no time limit. They have to because current-time is what determines the heating, which is what melts insulation. So unless you want to sharpen your pencil to actually design the circuit you get hemmed in using the worst case.

For a long run such as this, though, you start to run into problems even at reduced power due to voltage drop as well. A ~8,000 lbs class winch with a 20 foot run (remembering it's a 40 foot loop) you'll get 15% voltage drop at 450 amps even with 1/0 AWG. That'll be maybe 2 V or so. A 2 AWG is around 25% voltage drop at 40 feet with 450 A. But at 250 amps a 1/0 AWG at 40 feet is 8%, so a volt or so over that distance is probably tolerable for something that is infrequently done.

But in terms of heating 450 amps will bring a 1/0 AWG cable to 105°C in about 150 seconds in an 40°C ambient environment. It will take a lower current of 250 amps nearly 500 seconds to raise a 1/0 AWG conductor to 105°C.

Comparing those values on 2 AWG for 450 A the rise from 40°C to 105°C takes 60 seconds and 250 A about 190 seconds. BTW, those are not absolute numbers, a lot of assumptions are made about still air and how heat is radiated. I don't know Warn's criteria but I think they supply either 2 or 4 AWG cables with their winches and this is why. For something that will draw a max of 450 amps a 2 AWG will tolerate short durations such as 15 seconds as long as overall duty cycle is limited.

It isn't always simple because you have to be practical on cost, size, weight and balance realistic expectations. Whether the voltage drop or heating would be a problem depends on your criteria for acceptable. And remember too that how you size your fuse or breaker will also factor into safety.

 

[RoyJ]

Those wire charts have no time limit. They have to because current-time is what determines the heating, which is what melts insulation. So unless you want to sharpen your pencil to actually design the circuit you get hemmed in using the worst case.

For a long run such as this, though, you start to run into problems even at reduced power due to voltage drop as well. A ~8,000 lbs class winch with a 20 foot run (remembering it's a 40 foot loop) you'll get 15% voltage drop at 450 amps even with 1/0 AWG. That'll be maybe 2 V or so. A 2 AWG is around 25% voltage drop at 40 feet with 450 A. But at 250 amps a 1/0 AWG at 40 feet is 8%, so a volt or so over that distance is probably tolerable for something that is infrequently done.



Comparing those values on 2 AWG for 450 A the rise from 40°C to 105°C takes 60 seconds and 250 A about 190 seconds. BTW, those are not absolute numbers, a lot of assumptions are made about still air and how heat is radiated. I don't know Warn's criteria but I think they supply either 2 or 4 AWG cables with their winches and this is why. For something that will draw a max of 450 amps a 2 AWG will tolerate short durations such as 15 seconds as long as overall duty cycle is limited.

It isn't always simple because you have to be practical on cost, size, weight and balance realistic expectations. Whether the voltage drop or heating would be a problem depends on your criteria for acceptable. And remember too that how you size your fuse or breaker will also factor into safety.

I realized the winch situation is more voltage drop limited than thermal, hence I used the resistance on your chart to calculate v-droop. I did forget to include the negative cable though, so for my arbitrary 10% v-droop limit, and 24' run (ext cab long bed), I'd need something ridiculous like 4/0 (to get .05 ohm/1000'). Or ground to the frame with a GOOD connection.

In terms of heating time - most winches have a 1 min max duty cycle @ max line pull, so based on your info a 2 gauge can do it @ 450 amp, just barely though! And 24' might just push it over the limit. Voltage loss would be off the charts...

Your last paragraph hits the nail on the head on why Warn would offer a small gauge cable, SB175 connector, for a 24' run - it's a good compromise of cost. But for me, a 25% v-droop for the cable alone, plus more losses for the severely undersized connector, would kill the line pull performance of a 450amp winch. Remember the winch charts are based on 1st layer. With 4 - 5 layers, it'll be fairly easy to hit 450 amps. (~6200 lbs for a Warn 9.5)

Again, that's why I did a rear remote battery set (near the tailgate). It's a lot more economical than a 1/0 to 4/0 run, plus jumbo sized connector. I can efficiently charge the battery from the alternator with a cheap 4awg aluminum cable run, including a DC-DC charger. During winching the batteries are directly connected to the winch. I need the aux batteries anyways, so that's free. The 4' of 1/0 run doesn't cost much.

 

[RoyJ]

Don't forget that the start voltage with an alternator running is closer to 14.5V.
Cheers,
Peter
OKA196 motorhome

Yes, but it doesn't stay there long at winching current!

When I hooked up a carbon pile tester to my alternator, it took half a second to dip below 13v once I exceeded the alternator output. Another second or so (@ 400 amp) before system voltage is below 12.0v

I think a healthy battery (like pure lead AGM or Trojans) might hold 10.5v or so at winching currents, provide the alternator is supplementing 120 amps or so. Sure envy guys with 400+ dual alternators...

 

[Peter_n_Margaret]

Anyone who presses the GO button and keeps his finger on that button for more than 20 or 30 seconds is asking for grief and and it is the gaps between where recovery of the batteries (and cables) takes place. Also, most of a recovery will be well below maximum pull power.
It is unusual for a recovery to be an urgent exercise, so take it quietly and all will generally be sweet.
Cheers,
Peter
OKA196 motorhome

 

[DaveInDenver]

Remember the winch charts are based on 1st layer. With 4 - 5 layers, it'll be fairly easy to hit 450 amps. (~6200 lbs for a Warn 9.5)

This was done for the winch I own, an older XD9000.

Again, that's why I did a rear remote battery set (near the tailgate). It's a lot more economical than a 1/0 to 4/0 run, plus jumbo sized connector. I can efficiently charge the battery from the alternator with a cheap 4awg aluminum cable run, including a DC-DC charger. During winching the batteries are directly connected to the winch. I need the aux batteries anyways, so that's free. The 4' of 1/0 run doesn't cost much.

That's a sensible approach.

 

[verdesard0g]

This info is exactly why I have a hydraulic winch on my truck. If you need a rear winch there are quick disconnects for hydraulic lines. 100% duty cycle at 100% load.