DIY trailer build - battery in trailer or vehicle?

[AviatorJones]

Hey folks,

After attending Expo East last Saturday, my wife is (mostly) on-board with my hair-brained idea of converting our 5x8 utility trailer to an overland/camping trailer.

One question I have for the peanut gallery is around on-board power. We would like to have lights, powered water supply system, and eventually a fridge. My DD and primary tow vehicle is a 2014 Silverado LT Z71, but we also have a 2003 Jeep TJ that we would like to take if we're going on more 'adventurous' trails. With that in mind, what are the pros/cons of having the power source (battery) for the trailer systems stored in the trailer itself vs. the tow vehicle?

Off the top of my head, I would think it would be easier to use the vehicle alternator to keep the battery topped off while driving if the battery is in the tow vehicle, but maybe that's easy to do with the battery in the trailer as well? There is also added cost of having dual-battery setups in both tow vehicles. Also, having the battery self-contained in the trailer means really any vehicle can tow it and use it (assuming the charge capabilities are easy to pass-through from alternator to trailer).

Thoughts from folks who have done this?

Thanks,
CJ

 

[SongDogOverland]

We did the trailer build for our tj, the biggest thing is watch your weight, have trailer brakes if possible. The battery idea is great with solar to keep it charged. Have fun, the sky’s the limit with imagination on these things.

 

[AviatorJones]

We did the trailer build for our tj, the biggest thing is watch your weight, have trailer brakes if possible. The battery idea is great with solar to keep it charged. Have fun, the sky’s the limit with imagination on these things.

What kind of power setup (if any) do you have on your trailer?

I like the brakes idea, too, especially with the TJ - easier to get the cart before the horse with that short wheelbase. Are you doing electric brakes or surge brakes on the tongue?

 

[bgenlvtex]

Sounds like a minimalist build, I would personally treat it as such and use a portable power station.

However if there was to be a dedicated battery specifically for the trailer only, I would want the battery mounted to the trailer.

 

[smritte]

I built my trailer as sort of a minimalist build. Battery up in the front box, tow rig charges it and solar tops it off. The amount of battery you need is based on your power draw and how long your stationary.
Half of my trips im in a diffrent spot each night and the other half I can be base camped for a week, exploring with my vehicle.

Forgot to add. 50qt fridge, lights, roof fan and usb chargers. Trailer box has outlets for inverter and power for my diesel heater.

 

[AviatorJones]

I built my trailer as sort of a minimalist build. Battery up in the front box, tow rig charges it and solar tops it off. The amount of battery you need is based on your power draw and how long your stationary.
Half of my trips im in a diffrent spot each night and the other half I can be base camped for a week, exploring with my vehicle.

Forgot to add. 50qt fridge, lights, roof fan and usb chargers. Trailer box has outlets for inverter and power for my diesel heater.

How are you charging from the vehicle - are you running through a 7-pin connector or are you running a more dedicated line from the alternator to get more juice back there?

 

[smritte]

I run a 4gauge feed to the rear. There's a junction and separate fuse/relay panel. From there I run 8gauge to my 7 pin and 10 gauge into my trailer. This way I have very little voltage loss.

 

[grubworm]

One question I have for the peanut gallery

that's what we're here for!


i did a cargo conversion a couple years ago and i would definitely want the battery in the trailer. because of the high current draw of 12vdc. i think its all around better to have the battery centralized in the trailer and the benefits of that far outweigh the extra weight of a battery. no matter what you have NOW...your power requirement will only go up. im still adding extra USB ports here and there and adding extra lights, or this or that...cant imagine having a battery in the tow vehicle and then having to run every wire back to the trailer.

i'd go with something scalable and go from there. start with a 50ah battery if you are worried about weight and see how it does. if you have to increase ampacity over time, just swap it out with a 100ah. you can use a 7pin connector and there is a pin that will charge the battery while the alternator is going, but i prefer to use solar mounted on top and i carry a battery charger in case i need to charge the battery if it is very overcast and i get access to a 110v outlet.

here is a link for my build i posted on here and i think i have the battery set up described in a little detail. if you have any specific questions, just ask or DM or whatever. be glad to help

Modular cargo conversion

ok...long story made even longer... i owned enclosed trailers when i had my construction company. they are relatively simple and pretty well made and i had one for nearly 20 years and ended up giving it to my neighbor, so their longeviety is pretty good. i also had RVs that were crappy made...

www.overlandbound.com

 

[reaver]

I too run a battery in my trailer. 100Ah lifepo4 along with a 20A dc-dc charger mounted in the tounge box. I also have a 20A solar charger in there, that I plug a 120w panel into when needed.

Vehicle connection is handled by a 3 pin anderson plug that connects to either my truck, or my Xterra. Both run 4ga from the starter battery, through a fuse, to the rear of the vehicle.

Trailer runs a fridge, water pump, and many lights.

 

[Boucher]

So mine has 2 Lithium Batteries and got some SLIM 100 Watt solar panels for the Roof and later I added another panel to the front as I had the space

 

[AviatorJones]

Thanks for all the replies here. Great useful feedback, for sure. Love the drawing of the layout @Boucher !

The more I think about how we will use a trailer (at least initially), we will mostly be doing 1-3 night 'drive to destination --> set up base camp --> roam around in tow vehicle', so there isn't a TON of opportunity for en-route charging other than getting to the destination. I think Phase 1 will be a 100ah battery in the trailer that I charge up at home, cool down the fridge at home on shore power, and then run off battery after that. Phase 2 would be adding basecamp solar capabilities, and then maybe add vehicle charging after that.

I don't know.. That's my idea right now, but it's only 2pm here so it's likely to only change 5-1000 times before I go to bed tonight.

The good thing is that the trailer is nothing more than the start of a drawing right now, so plenty of time to figure this out, but at least I have narrowed it down to having battery power stored in the trailer rather than trying to power everything from a second vehicle battery.

 

[Boucher]

Thanks for all the replies here. Great useful feedback, for sure. Love the drawing of the layout @Boucher !

The more I think about how we will use a trailer (at least initially), we will mostly be doing 1-3 night 'drive to destination --> set up base camp --> roam around in tow vehicle', so there isn't a TON of opportunity for en-route charging other than getting to the destination. I think Phase 1 will be a 100ah battery in the trailer that I charge up at home, cool down the fridge at home on shore power, and then run off battery after that. Phase 2 would be adding basecamp solar capabilities, and then maybe add vehicle charging after that.

I don't know.. That's my idea right now, but it's only 2pm here so it's likely to only change 5-1000 times before I go to bed tonight.

The good thing is that the trailer is nothing more than the start of a drawing right now, so plenty of time to figure this out, but at least I have narrowed it down to having battery power stored in the trailer rather than trying to power everything from a second vehicle battery.

Let me know If you need any help with ideas or how to

 

[TheBison]

I actually have both. My trailer is a small squaredrop trailer and I have a smaller 35 Ah battery with solar etc. in it to run vent fan, lights, charge phones, etc. We don't always take the trailer and my fridge/freezer is in the bed of the truck, so I have a 100 Ah house battery with solar etc. in the truck to run the fridge, have camp lights, etc. We also have a water tank in the bed of the truck so the house battery runs a water pump too.

 

[Sparksalot]

I actually have both. My trailer is a small squaredrop trailer and I have a smaller 35 Ah battery with solar etc. in it to run vent fan, lights, charge phones, etc. We don't always take the trailer and my fridge/freezer is in the bed of the truck, so I have a 100 Ah house battery with solar etc. in the truck to run the fridge, have camp lights, etc. We also have a water tank in the bed of the truck so the house battery runs a water pump too.

My setup is similar with a small trailer battery, and most of the load in my truck.