Ram 1500 - 12v power to trailer

[GordonThree]

I've upgraded my tow from a 290 hp station wagon to a 395 hp truck and it's really made a difference pulling my little Sportsman.

One thing the Ram lacks, and it's minor, is the ability to charge the trailer batteries.

My wagon had an after market trailering package installed, and once I upgraded the ground wire in the car side of the 7 way, it provided almost 30 amps to the trailer. 30 amps isn't huge, a drop in the bucket to my 800 AH battery bank, but still better than nothing.

The Ram, a 2013 1500 "Outdoorsman" (factory 7 way setup and factory brake controller), on the other hand provides a measly 10 amps to the trailer. The gas solenoid on my fridge takes 3 amps, the inverter's electronics on standby takes another amp or so, leaving 6 amps to charge the batteries.

The trailer safety lights all work, and shine brightly. The 10 amps is measured across a precision shunt by the battery management controller which is part of my inverter setup.

Have other Ram drivers noticed a low charge current through the factory 7 way on their truck?

Only mention I find of power supply for the trailer battery is fuse F30, 30 amp, named "Trailer Tow Receptacle". The fuse is intact. I next opportunity I have to fiddle, I will pull it and see if BAT+ goes out on the 7 way.

[Perrysburg_Dodg]

frank henn wrote:
If it has a factory tow package pull the top off of the fuse box under the hood and put a fuse in the spot that says trailer this wil enable your truck to charge the battery

X2 My truck would not charge the TT batteries until the RV dealer installed the fuse in the power distribution box under the hood! 😮

After that we NEVER had an issue with dead batteries again.

Don

[john_bet]

PaulJ2 wrote:

john&bet wrote:

PaulJ2 wrote:
I guess I would just look at the size wire that is there now--probably #12,#14. Then just parallel another say #10,12 back to the hitch. Should give you a lot more current and may be enough.

Not a good idea to parallel that small of a wire.

Not a problem. Two #12's gives you a #6 wire. He already said it is protected with a 30 amp fuse. If one wire should break you are back to your 10 amps again.

I stand by what I said. Not sure about vehicles, but not legal in home,commercial,industrial applications.

[PaulJ2]

john&bet wrote:

PaulJ2 wrote:
I guess I would just look at the size wire that is there now--probably #12,#14. Then just parallel another say #10,12 back to the hitch. Should give you a lot more current and may be enough.

Not a good idea to parallel that small of a wire.

Not a problem. Two #12's gives you a #6 wire. He already said it is protected with a 30 amp fuse. If one wire should break you are back to your 10 amps again.

[AlbertaNewbie]

why not save the 100bucks in material and put it towards a solar system. Save up $1000 and put on 250 watt panel with a good Morningstar 45 amp mppt controller and add panels as money allows.

[john_bet]

PaulJ2 wrote:
I guess I would just look at the size wire that is there now--probably #12,#14. Then just parallel another say #10,12 back to the hitch. Should give you a lot more current and may be enough.

Not a good idea to parallel that small of a wire.

[PaulJ2]

I guess I would just look at the size wire that is there now--probably #12,#14. Then just parallel another say #10,12 back to the hitch. Should give you a lot more current and may be enough.

[dodge_guy]

Um......no! You're definitely overthinking this. Just run it as is. I ran from IL to MT for a 2 week trip with my fridge running off a 1200W inverter so i didn't have to worry about the fridge on proane during the trip. Some days were 8-11 hours and the trailer battery never had an issue being charged through the factory truck harness.

[GordonThree]

russgary wrote:
I have a 400 ah agm battery pack, and my TV has a 130a alternator. I ran 4 Ga from the under hood area to the rear bumper and installed Anderson 175a connectors. There is another 4 Ga duplex wire attached to the trailer (recycled jumper cables) on each end is a 100a breaker and under hood is a 120a spat solenoid activated by ignition on. Its not a true battery isolator, but, it is an established method of keeping the starting battery from dying.. I have not installed the shunt and ammeter in this setup yet, so, I cannot quote the actual amps casual observations suggests however the charge is massive.

sounds exactly like what I want to do.

regarding other posts about alternator rpms. the "output" of the alternator depends only a little on rpm, mostly the output is controlled by the engine computer, reading the state of the starting battery. The wiring under the hood provides a low impedance path between the alternator, the computer, and the starting battery. Compared to the high impedance path between whatever 20-30 amp fuse and the trailer BAT+ connector uses (probably very skinny wire.)

The engine computer can only "see" the starting battery, and once it is charged, output of the alternator is reduced to provide only enough power to run the engine and accessories. Upgrading to heavy gauge wire between the alternator and the trailer allows the engine computer to "see" the trailer batteries, and increase alternator output to charge them as well.

[dodge_guy]

Have you checked your power to the trailer at 2000 rpm? that is where the alternator will be putting out on the road. at idle they do not put much out!

[russgary]

spat solenoid=spst. Smartphone keyboard giant thumbs etc.

[russgary]

I have a 400 ah agm battery pack, and my TV has a 130a alternator. I ran 4 Ga from the under hood area to the rear bumper and installed Anderson 175a connectors. There is another 4 Ga duplex wire attached to the trailer (recycled jumper cables) on each end is a 100a breaker and under hood is a 120a spat solenoid activated by ignition on. Its not a true battery isolator, but, it is an established method of keeping the starting battery from dying.. I have not installed the shunt and ammeter in this setup yet, so, I cannot quote the actual amps casual observations suggests however the charge is massive.

[APT]

GordonThree wrote:
I just didn't feel compelled to explain myself to you. Since that has obviously offended you, I will indulge.

You think too much of yourself. No one on the internet offends me. 🙂 Have a great day and good luck with your solution!

[GordonThree]

APT wrote:

GordonThree wrote:

APT wrote:
Why not charge at home before leaving, AC/DC converter you already have? If the batteries are nearly full capacity before you leave, you don't need any "charging" while driving.

This is not relevant to the original topic.

You can ignore my comments, but you are creating a solution to a problem that does not exist IMHO, all the while spending your money to do so. Think outside your box.

I just didn't feel compelled to explain myself to you. Since that has obviously offended you, I will indulge.

Here's a hypothetical for you.

Lets say I take a few weeks off work for a road trip. I leave home, with fully charged batteries. I boondock for a few days at a National forest campground / dispersed campsite. I get bored with that spot, and drive 4-5 hours to another location, not home mind you. When I get to the second location, I would have liked for more than a pittance of energy to be returned to my battery bank. Instead, I get to the second site, and fire up the generator for a few hours.

While driving, my wagon was putting roughly 20 amps per hour of energy back into the bank. My brand new truck does not do this, and I am seeking feedback as to whether this is common, or a problem with my truck. Many folks have answered, and I see it is common, therefore as it is a problem for me (and not necessarily others), I am going to investigate solutions.

[frank_henn]

If it has a factory tow package pull the top off of the fuse box under the hood and put a fuse in the spot that says trailer this wil enable your truck to charge the battery