I finally broke down and got a dedicated battery and box to go on my flatbed to run my winch. I would like to run a wire from the truck to the trailer to keep the battery charged as opposed to removing and recharging after every outing. I'm not entirely sure how to go about this as electricity is not one of my strengths. Can I just run one wire from the alternator on the truck to the trailer battery and then the battery ground to the trailer frame or do I need another ground wire coming from the truck as well? What gauge wire should I use?

 

You'd be much better off buying a converter rather than just running a charge wire because it'll boil the battery dry. See here:

 

Can you say a little more about how long it takes before your battery goes flat the way you are using it now or something about winch run time to get a sense of what you are doing? Since this is a flatbed with a winch, I am guessing you do not want to go through the process of plugging in an converter or charger at night.

Steve

 

It's an occasional use item, sometimes it will sit for a couple months and sometimes I may use it several times in one month. I will usually just use it to winch a vehicle on and let gravity unload it. I haven't run it dead yet, as I usually just tossed it in the truck when I needed it then would put in the garage on a charger for a few hours after I was done. I would just like to try and make it maintenance free, because I am sure I will forget to remove and charge it one day and try to winch with a dead battery next time I go out.

 

This type of use is hard on a battery as they have a longer life span, if you can keep them close to fully charged rather than the discharge/recharge cycle that would result in this scenario.

If you have a seven pin plug on your truck already, there would normally already be a charge lead on one of the pins and all it would take is a wire running between the plug off the trailer to the trailer battery and a ground lead between the battery and truck chassis.

If you only have a four pin plug from truck to trailer or no plug at all connecting the two, then you have no charge lead at the rear of your truck and you basically need to run a lead between the truck and trailer battery positive terminal and a lead from the negative on the trailer battery to the truck chassis. Battery to truck frame will suffice for the negative.

The kicker here is charging the battery in this manner will depend on engine run time on the truck and the size of the lead between the two batteries. Normally, on a travel trailer and such, the lead is only a #10 wire fused at 30 amps. the bigger the lead between the two (within reason0, the more rapidly the trailer battery will charge and the lead off the truck battery has to be fused at the rating for the wire you run.

Operating in this manner, is not ideal as the battery sits so long between runs and it would do better if it were on a charger between runs, or as suggested earlier on a "smart charger" or "smart converter" like many of those found in RVs.

Good luck,

Steve

 

I do have the 7 pin plug but I installed it so I know there is no hot wire currently running through it, just lights and brakes. It shouldn't be a problem to get it wired up like you said. Would a deep cycle RV or marine type battery be better suited for the use I have planned? If I predict it will be sitting for an extended period of time I have no problem putting it in the garage on a charger/maintainer.

 

Yes, you do want a deep cycle battery and the key to your success will most likely be how often the battery is used and kept charged while underway in relationship to how deeply discharged it is during use. Things like this are always hit or miss until you get your usage pattern established.

Good luck,

Steve

 

You don't have brakes? In IN they are required, with breakaway. on any trailer >=3000lb gross.

Another option would be to install the battery in your truck as a second battery and run heavy cables with appropriately sized Anderson connectors to the rear of the truck with matching cable/connector to the winch.
For that matter, based on how you describe your usage, you wouldn't even really need a second battery.

 

As long as he has a charged battery on the trailer, he has brakes in the event of a breakaway and his post says he ran the brake lead from the truck, just not the charge lead, if I am understanding his set-up.

Steve

 

You're right, I misread, at least about the brakes. I'm not clear if he has a break-a-way setup. If he does and is running it off the winch battery, or plans to, then my alternative wouldn't support it, only the winch.

 

I have a car battery used to power the break away switch to the brakes, Also used for a winch. If I remember correctly the breakaway instructions said to wire the switch so that with the lights on the auxiliary battery would be charged.

 

Yes, I do have brakes , the trailer weighs 3000lbs empty so I couldn't imagine pulling it around without them. I don't have a break away setup though but will be looking into it as we started carrying them at my work. My truck already has dual batteries and I toyed with the thought of just running cables from the truck battery to the winch but people made it sound like I would need 1" thick cables to handle the amp draw due to the length they would have to be.

As far as driving time, I'm about 15-20 minutes from anywhere so that's a minimum. The battery is only used to winch a vehicle on which takes 2 minutes or less. This last month has been an exception as I had to use the winch to load and unload a vehicle several times on one outing and then another vehicle the following week without charging in between. The battery I have right now is a 1000 amp unit from another F-250.

 

For a rear mounted winch used for self recovery, yeah, you'd want something like 1/0 or 2/0 cable.
For what you're doing you're probably pulling at most 2,000lbs, more likely around 1,000. You'd probably be fine with #1 or even #2 cable.
Knowing which winch you're using and the length the cables would need to be is what's needed to know what size cable is needed.

 

Warn sells a complete 20' quick-connect wiring kit to run front battery to rear bumper using 2-ga cable for those with a rear mounted recovery hitch. Includes relay, switch, and the whole package. Advertises it will handle 2000-6000 pound loads. Gets very good reviews from owners. You may not be running much beyond that depending on the length of the trailer tongue.

Here is a link Warn 32963 Quick Connect Power Cable | eBay

Steve

 

Thanks for the link, in the long run that would be a more efficient way than replacing batteries. I looked it up at work and can actually get the same kit $50 cheaper which is only $30 more than the next battery would cost me. I am running an old school Warn winch, similar to the 8274 but power in/out instead of free spool release. My truck is a long bed super cab, I think 20' might get me to the bumper. I may have to get 2-3' more cable to reach the winch over the trailer tongue. Would this still work ok as long as I have more of the same style/size of cable?