Rig to Trailer Battery Charging

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Jack Houston

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Hi all,

I'm in the process of building my trailer. I plan on having built in power. I haven't decided if I'm gonna use a dual battery or single battery system. What's the best way to charge the trailer battery system using my truck? Can I just connect it directly to the truck battery? I'd like for it to be as simple as connecting trailer lights to the truck.
 

Boort

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@Jack Houston
I don't see what kind of rig you're running. If you already have a 7-Way Trailer trailer connection on your rig you likely have 30 or 40 Amp charging circuit installed. See this post for more details:
https://www.overlandbound.com/forums/threads/running-power-to-your-truck-bed.15505/#post-228098

On my 4runner and the folks Sequoia the circuit was already there, hooked up, and switched by the ignition. I had to add it to my 97 Tacoma and Dad's Ford Van, Took a weekend using using a kit from E-trailer.com. Yes you CAN take it straight to the battery but I regret doing that on the Tacoma I with I had put in a switch and relay so I could either turn it on from the cab or only when the engine is running. Direct hookup means I need to unplug the trailer if I'm going to be parked for much time or the trailer can drain the Start battery leaving me waiting for a jump start.


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phxdsrtrat

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How new is your rig? This is a really open ended question especially with modern vehicles and their advanced charging systems that drop the voltage when they detect your rig's batter is charged. I've done an enormous amount of research on this topic and spent lots of dollars to make sure my trailer battery gets fully charged while on the road.

-Curtiss
 

Jack Houston

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I probably should have been more detailed. I have a 2003 Ram 1500 with a four way connector. I'm just beginning my build so I can change things pretty easily. I'll look into what both of you have posted.
 

Winterpeg

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How new is your rig? This is a really open ended question especially with modern vehicles and their advanced charging systems that drop the voltage when they detect your rig's batter is charged. I've done an enormous amount of research on this topic and spent lots of dollars to make sure my trailer battery gets fully charged while on the road.

-Curtiss
This helps....
https://www.hkbelect.com/
 
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Boort

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@Jack Houston
I probably should have been more detailed. I have a 2003 Ram 1500 with a four way connector. I'm just beginning my build so I can change things pretty easily. I'll look into what both of you have posted.
Check to see if your 4-pin plugs into a factory wiring harness, rather than the back of the taillights or a T-connector in the taillight circuit. If it uses a factory tow circuit then you may just need one of these:
https://www.etrailer.com/Custom-Fit-Vehicle-Wiring/Dodge/Ram+Pickup/2003/HM42190.html?vehicleid=20031229735
Look under the back end of your pickup for a harness connector like this:

RAMSideHarnessPlug.png

If the 4-way plug uses a t-connector or splices into the taillight circuit, you'll be in a similar situation to me when wiring the 97 Tacoma. This is what I used:
https://www.etrailer.com/Wiring/Curt/C57186.html

Here is the schematic provided with that kit that I used:


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Funmobile

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On mine, I mounted a dual blade gray Anderson plug on my rear bumper and a matching plug on the trailer. Both are mounted to the respective batteries and I run a manual kill / disconnect switch on the trailer. Also on the trailer, I also run a 30w goal zero panel with a charge regulator. The Anderson plugs are extremely durable and easy to use. I will be adding a second to the front bumper. That will provide me with a front / rear option for Anderson / traditional jumper cables.
 

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McGrizzly

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h
Hi all,

I'm in the process of building my trailer. I plan on having built in power. I haven't decided if I'm gonna use a dual battery or single battery system. What's the best way to charge the trailer battery system using my truck? Can I just connect it directly to the truck battery? I'd like for it to be as simple as connecting trailer lights to the truck.
Hows the trailer coming along? I am curious to hear how you are running power.
 

dstock

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I’ve been looking at getting this set up. That way I could use the battery to jump start my car if needed as well as keep it isolated.

https://www.nationalluna.com/product/battery-manager-diy-kit
I would avoid the NL system, they don't like the heat. Many threads on Expedition Portal regarding them failing, including the one I started. You'd be much be off with a Blue Sea 7622 ML-ACR which will do the same thing as the NL.

Sorry, tried to link it on Amazon but it's not working...
 
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