Trailer mounted battery vs truck mount

Danielle

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I use my car trailer a lot now and need opinions on best way to permanently power the trailer winch.

Right now I use a marine battery next to the winch on the trailer, then trickle charge that battery occasionally.

I would like to wire a plug from truck to winch and eliminate the trailer battery, one less thing to steal or forget to charge.

Should I stick with what I'm doing and invest in a more secure battery box on trailer?

Or run power from truck to trailer? Third battery? Upgrade alternator? What is a weather safe plug brand?


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DieselDc

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If you were to use it all the time, leave it as is and let it trickle charge. If you use it occasionally like me on one of my dump trailers, run the power line to the back. I did nothing special and certainly no upgraded alternator.

Just one 1/0 12v power back to the bumper with them quick marine connectors.

Upfront is the quick disconnect for when I’m not using it. It’s close to the battery so I don’t have a fuse.


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DieselDc

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If it helps any, great! If not no worries :)

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Danielle

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You had me at Amazon haha. Thank you

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subway

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while it might be nice to have the power connector on the rear of your truck to plug in things like a inverter, jumper cables or hitch mounted winch. cant you set the trailer battery to charge through the trailer connector while you drive around?

after that a welded heavy metal strap with some hard to get to bolts should keep your battery safe on the trailer from all but the most the determined tweakers.
 

79jasper

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while it might be nice to have the power connector on the rear of your truck to plug in things like a inverter, jumper cables or hitch mounted winch. cant you set the trailer battery to charge through the trailer connector while you drive around?

after that a welded heavy metal strap with some hard to get to bolts should keep your battery safe on the trailer from all but the most the determined tweakers.
Now don't go getting all ethical..... lol

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laserjock

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Amazon also sells ready made wire kits with the Anderson connectors if you don’t want to piece it together.
 

Thewespaul

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I set up our gooseneck dump trailer with a battery in the frame next to the pump and motor, it gets a trickle charge from a small solar panel by the spare on the gooseneck. I imagine you could rig something similar with a car hauler. I’ve wired it so the battery is charged by the alternator but ran into issues with overworking the alt in that specific scenario
 

laserjock

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I set up our gooseneck dump trailer with a battery in the frame next to the pump and motor, it gets a trickle charge from a small solar panel by the spare on the gooseneck. I imagine you could rig something similar with a car hauler. I’ve wired it so the battery is charged by the alternator but ran into issues with overworking the alt in that specific scenario
Correct. If you don’t have a circuit in there to keep it from pulling on the truck through the 7 pole, that could cause problems.
 

u2slow

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I ran #2/0 to an anderson connector at my back bumper. That way I can plug in my atv/utility winch (receiver mount) or bridge batteries with my camper unit.
 

gandalf

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When I had my cabover camper on my '86 I had a dedicated battery for the cabover, mounted in the cabover. I powered it through a Cole Hesse battery isolater. The cabover received power through the isolater, but the isolater would not allow the cabover to draw power from the two truck batteries. Hence the term 'isolater'. I wanted those truck batteries in good shape to start the truck after a week of camping. I ran the power through the isolater to an auto-reset circuit braker, then to the rear bumper to the trailer jack. One of the pins on the jack was dedicated to the cabover battery.

I think it was Cole Hesse, but it could have been Cole something else.

Pictures to follow.

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Danielle

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My dad had a nice battery box with a new deep cycle and someone cut the wiring and took battery and box while parked at a job site -cuss-cuss-cuss

I'm going to read up on isolaters, that sounds like a good idea if I do the charging idea and I still have the old truck camper for when just me and the girls...

So much to think on now, thanks oilburners!
 

Big Bart

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My suggestion is one of these two.


1) As DieselDC said put a heavy duty jumper/winch connector in the back of rig. Hook up and use your winch. Use to power something. Jumpstart something, etc. I am going to do this for the winch on the front of my jeep. (Power the winch or unplug and use a jumper cable to help jump start another vehicle.)


2) But what is perhaps more useful in your case is to use the 7pin trailer wiring and a battery on the trailer. (Always ready to go.) In many cases flat/car trailers use the center pin for back up lights to power and prevent surge brakes from being applied when backing up. But with some travel trailers the back up light pin is used for house battery charging. (Flat and travel trailers generally do not have back up lights.) If you do not have a surge brake system with a back up lock out valve, you can do the below with the back up light pin. (Middle pin on the 7 pin light duty vehicle trailer socket.)


a) When doing this set up it would look like Gandalf's set up. Hook the isolator per the directions to the truck. Then from the isolator to a 20-30 amp fuse box (The small box with posts in above picture.), fuse box to the trailer connector (Middle pin) on the back of the truck.


b) Jump the back up light pin on the trailer wiring connector and run to the positive side of the battery on the trailer. Keep in mind this all should be a good 12g or larger wire. Something 18 gauge could over heat trying to charge the trailer battery especially with that long of a wire. You also should try to charge the trailer battery from time to time to prevent it from getting to low or dying. Or as TheWesPaul said keep a solar panel on it to trick charge it during long storage times. The concern is if the trailer battery is low, say 3 volts it may try to pull a bunch of amps over the system to charge it. Then heat up or burn a small gauge wire. Keep in mind that is what the automatic fuse is there to prevent. So if you keep the battery between 10-12.4v it will only draw little amperage to charge it and should not have any issues using say 12g wire.


Good luck!
 
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TNBrett

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One of the 7 pins in a 7 way plug is already designated as trailer charging. Not sure on the bricks and bulls, but on the OBS it’s fed by a relay so that it only feeds the trailer with the key in the run position. This keeps it from drawing down the batteries in the truck when stopped. All that needs to be done is connect the trailer battery to that pin in the plug.

PLEASE DO NOT wire a standardized connector incorrectly. It can only cause problems and confusion for the next guy. What if you borrow someone else’s trailer, or you sell the truck or trailer.


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Big Bart

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One of the 7 pins in a 7 way plug is already designated as trailer charging. Not sure on the bricks and bulls, but on the OBS it’s fed by a relay so that it only feeds the trailer with the key in the run position. This keeps it from drawing down the batteries in the truck when stopped. All that needs to be done is connect the trailer battery to that pin in the plug.

PLEASE DO NOT wire a standardized connector incorrectly. It can only cause problems and confusion for the next guy. What if you borrow someone else’s trailer, or you sell the truck or trailer.


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TNBrett,


I think we are backing into this from different ends to get a solution. I think we both make good points, our fellow members will have to decide what is best for them.


My concern with using the standard power pin you suggested, that is used to charge the brake away battery and I believe used by some electric over hydraulic pump's as I recall. (Which I have.) So not sure I would want to be goofing with brakes to charge a trailer winch battery that is dead and drawing away the power. Or worse yet blows a fuse while underway. To your point maybe a charged onboard battery in parallel saves the day!


I have yet to see any trailer that had back up lights, so this terminal is not generally used unless you have surge brakes and at that a back up valve. (Trigged by power from the back up lights.) I have also seen what I have described on two or three different wiring diagrams and spec'd for travel trailers so guessing it's not an uncommon way to wire for charging the house batteries.


Yes to your point, sell your truck and don't mention. Next guy to own has a snowmobile trailer with surge brakes and back up valve, he will find out quickly when he backs up he has an issue. (Turns out I was that guy!) I have a trailer with surge brakes and the back up valve so I am wired this way now. But when I bought the truck he had house power via a isolator and then going to the reverse pin. I figured it out in under 10 minutes. Then decided to rewire as mechanic before did a half baked job (Splices, taps, loose wires, etc.) wiring for a trailer socket and a 5th wheel socket in the bed. Now its all ship shape and working great.
 

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