Travel Trailer Electrical Upgrades

[BuckeyeF350]

Since this really became a thread for the upgrades I made to our travel trailer's electrical system, I figured I'd edit the first post.

Our system includes:

• 1200W rooftop solar
• 200W deployable ground panels
• 400Ah Battle Born lithium batteries
• 3000VA Victron Multiplus-II inverter
• Victron 250|100 SCC
• Victron 100|35 SCC
• Victron Cerbo GX
• Victron GX Touch 70
• Victron Digital Multi Control
• Victron Lynx distributor
• Blue Sea fuses, breakers, bus bars, etc.
• Windy Nation welding cable and terminals
• 12V fans controlled by the Cerbo to ventilate the compartment
• 12V security camera system
• 12V hotspot
• Mopeka LPG sensors integrated with Cerbo

Near-term plans:

• 2x Victron Orion XS DC-DC chargers
• Additional 200W ground panels
• 12V conversion for weBoost
• 12V conversion for Starlink (I'm also considering just installing a dedicated 250VA Victron inverter for this)
• Mopeka sensors for fresh water and holding tanks integrated with Cerbo

Original Post:
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RAPSCALLION Upfitter Trailer Power Harness

I'm exploring using this as something of a switched DC-DC charger for our travel trailer. If I'm understanding things correctly, this should send 25 or 40 amps to the charge wire in the 7 pin depending on which upfitter I wire it to.

From what I can tell of my trailer wiring diagram, power goes from the 7 pin, to a junction box, to a disconnect switch, to the battery. If I were to wire this to an upfitter, what shuts it off once the batteries are fully charged?

I don't rely on my truck to charge the batteries all that often, and would prefer the simplicity and cost of this over a DC-DC charger.

Does this seem workable, or should I just go with a DC-DC charger?

 

[04sshd]

@BMCLIGHTS is a vendor here and Brian is super friendly and can answer any of your questions. I also think today it's still on special for their black friday special. As far as the upfitters, they shut off with the truck ignition or switch off unless you change them to be hot all the time then it would shut off with switch off. It would work like your truck batteries, only charging them when you're driving.

 

[Modman]

If I were to wire this to an upfitter, what shuts it off once the batteries are fully charged?

I think the answer is "nothing". If you are running wire all the way to the upfitter anyway just use that to power a DC-DC charger. A 20A charger plus wiring and disconnects wouldn't be much more than that BMC kit, although it is a nice "plug and play" setup for those that need a bit more power for trailer accessories. Then you will have a controlled system.

 

[Modman]

I think the answer is "nothing". If you are running wire all the way to the upfitter anyway just use that to power a DC-DC charger. A 20A charger plus wiring and disconnects wouldn't be much more than that BMC kit, although it is a nice "plug and play" setup for those that need a bit more power for trailer accessories. Then you will have a controlled system.

Like this one:

https://www.amazon.com/Renogy-Battery-Batteries-Multi-stage-Charging/dp/B07Q5VYPCF/ref=mp_s_a_1_3?adgrpid=127346158208&hvadid=604405543878&hvdev=m&hvlocphy=9016895&hvnetw=g&hvqmt=e&hvrand=4561554923814054680&hvtargid=kwd-456750661678&hydadcr=19224_13432048&keywords=20+amp+dc+to+dc+charger&qid=1701138156&sr=8-3&ufe=app_do%3Aamzn1.fos.304cacc1-b508-45fb-a37f-a2c47c48c32f

Mount it in your TT and run some wire up to the tongue to interface with a feed from an Upfitter on the truck using a 50A Anderson connector or equivalent...

 

[BuckeyeF350]

@BMCLIGHTS is a vendor here and Brian is super friendly and can answer any of your questions. I also think today it's still on special for their black friday special. As far as the upfitters, they shut off with the truck ignition or switch off unless you change them to be hot all the time then it would shut off with switch off. It would work like your truck batteries, only charging them when you're driving.

I asked them and it seems that it would work in theory and would certainly send a current to the battery bank. Just not sure what it would do to my battery bank without it going through the truck's charger or the converter in the trailer.

Thinking about it, I'm wondering what turns off charging from the truck to the 7 pin with the factory wiring.

 

[BuckeyeF350]

I think the answer is "nothing". If you are running wire all the way to the upfitter anyway just use that to power a DC-DC charger. A 20A charger plus wiring and disconnects wouldn't be much more than that BMC kit, although it is a nice "plug and play" setup for those that need a bit more power for trailer accessories. Then you will have a controlled system.

The plug and play of the BMC kit is the most appealing part to me. Seems like it'd be a lot easier to bring it out only when I need it, which isn't all that often.

I suppose I could probably figure out some kind of setup that would be similar, using a DC-DC charger. Maybe add plugs on the truck and trailer, with a cable to connect then when I want to use it.

 

[Modman]

Seems like it'd be a lot easier to bring it out only when I need it, which isn't all that often.

You would have this permanently installed due to the wire routing and connection to the Upfitter, unless I'm not understanding something...

 

[BuckeyeF350]

You would have this permanently installed due to the wire routing and connection to the Upfitter, unless I'm not understanding something...

Most/all of the setups I've seen have a plug somewhere in the bumper and a plug run from the DC-DC charger to the trailer tongue.

I'm not a fan of most of the mounting options I've seen for the Anderson connectors, and I'd have the additional wiring from the trailer when I'm not using it. I like that I could keep the BMC option stored until I need it and it goes away when I don't.

But...maybe I could install a female connector at the truck and another at the trailer, and use a length of cable with two male connectors to achieve the same thing.

 

[Modman]

I like that I could keep the BMC option stored until I need it and it goes away when I don't.

I still don't understand this. What do you mean by "stored"?

I would think the design intent is that you insert their harness at the rear of the bumper, run the feed to the Upfitter pigtail and it stays in perpetuity. When you need extra amperage you flip the switch. When you don't you do nothing.

Most/all of the setups I've seen have a plug somewhere in the bumper and a plug run from the DC-DC charger to the trailer tongue.

Correct, that is what I was suggesting above.

 

[BuckeyeF350]

I still don't understand this. What do you mean by "stored"?

I would think the design intent is that you insert their harness at the rear of the bumper, run the feed to the Upfitter pigtail and it stays in perpetuity. When you need extra amperage you flip the switch. When you don't you do nothing.

It looks like it plugs in line with the existing 7 pin, and then the 10 gauge wire for the upfitter. I could install a quick connect for the upfitter right by the 7 pin (should be an easier install than an Anderson connector) Then, I'm ready to plug and play with this, and no additional trailer wiring and no trying to figure out how to install an Anderson connector.

Correct, that is what I was suggesting above.

The people I've seen do this for a bumper pull have the connector zip tied to the receiver or something. I haven't seen a clean install of an Anderson connector in the bumper. Even then, I'd want to figure something out so the trailer side wiring isn't hanging out when I don't need it.

We're full time nomads and move around a lot. I'm always looking for small efficiencies, and not dealing with a charging cable when I don't need it is my goal. I'd like to be able to leave it in a bin in my truck, and only break it out when we're doing a Harvest Host, Cracker Barrel, etc. where I don't want to or can't use the generator or solar isn't keeping up.

This was our third consecutive stay at a Harvest Host. We ended up using the generator to top off the battery bank, because we had nearly a week of very little sun. We were driving about 6 hours a day, but the charge from the truck was barely enough to maintain the batteries. Most of our stays, we're going from full hook ups to full hook ups. When we head west again, I'd like to do a lot more BLM, Harvest Host, etc.

If this won't work then it won't work, but seemed like an easy option for better charging of our battery banks when we need it. If I go DC-DC charger, I'll probably just do two 30 amp Victrons.

Hopefully that makes more sense and gives some more background of why I'm looking at this as a potential option.

 

[Modman]

It looks like it plugs in line with the existing 7 pin, and then the 10 gauge wire for the upfitter. I could install a quick connect for the upfitter right by the 7 pin

Yep, that makes sense now with the quick connect for the Upfitter!

This is one of the cleanest installs I recall for the Anderson, behind a hinged license plate bracket:

Anderson Plug remote Warn winch and inverter power plug installed

I have a 2020 6.7 Tremor and a Warn 10k lb winch on a tray. I purchased the extended leads from Warn to be able to put the winch on the back as well. I also want to get a 3000-4000 watt inverter to use from the same power when needed. Looking for inverter recommendations as to max size with the...

www.fordtremor.com

 

[BuckeyeF350]

Yep, that makes sense now with the quick connect for the Upfitter!

This is one of the cleanest installs I recall for the Anderson, behind a hinged license plate bracket:

Anderson Plug remote Warn winch and inverter power plug installed

I have a 2020 6.7 Tremor and a Warn 10k lb winch on a tray. I purchased the extended leads from Warn to be able to put the winch on the back as well. I also want to get a 3000-4000 watt inverter to use from the same power when needed. Looking for inverter recommendations as to max size with the...

www.fordtremor.com

That is a clean install!

I don't have the skill to do that, and I don't think law enforcement would be happy with me driving around like that.

It seems like the main problem I'd have using the upfitter and BMC option is that it wouldn't stop charging the battery bank when it's full, and I don't want to damage my batteries. They're Battle Born and have a BMS, but from what I can tell, that doesn't cut the charge.

 

[JTredway]

RAPSCALLION Upfitter Trailer Power Harness

I'm exploring using this as something of a switched DC-DC charger for our travel trailer. If I'm understanding things correctly, this should send 25 or 40 amps to the charge wire in the 7 pin depending on which upfitter I wire it to.

From what I can tell of my trailer wiring diagram, power goes from the 7 pin, to a junction box, to a disconnect switch, to the battery. If I were to wire this to an upfitter, what shuts it off once the batteries are fully charged?

I don't rely on my truck to charge the batteries all that often, and would prefer the simplicity and cost of this over a DC-DC charger.

Does this seem workable, or should I just go with a DC-DC charger?

can this be utilized for the bed 7pin as well? Pardon the ignorance as I want to utilize a Dometic or Truma powered cooler in the bed.

 

[Modman]

can this be utilized for the bed 7pin as well? Pardon the ignorance as I want to utilize a Dometic or Truma powered cooler in the bed.

I don't see why not. This method has been documented and used by others to bypass the OEM power "control" on the 7-pin. It basically just overrides it with an external power feed. The BMC kit provides for a nicely packaged way to achieve this. For $30-40 you can buy the Dometic hardwire kit that will accomplish the same thing, however. Either way you will have to run a wire from the bed up to the battery or Upfitter.

Here is mine:

🛠️ - What did you do to your Tremor today? [2019-2024]

Did you do a write up or make a video as you did the install? I did. We will be posting it soon to FTE as well as here.

www.fordtremor.com

 

[BuckeyeF350]

It seems like the main problem I'd have using the upfitter and BMC option is that it wouldn't stop charging the battery bank when it's full, and I don't want to damage my batteries. They're Battle Born and have a BMS, but from what I can tell, that doesn't cut the charge.

@BMCLIGHTS

Is that correct, that I'd be sending power to the batteries when the upfitter was on and there's no cut off when the batteries are charged?

 

[01tundra]

I would run a dedicated circuit and get the best performance out of your DC-DC charger, instead of depending on undersized wire both in the truck and trailer.

I ran a dedicated 4 AWG circuit to the back of the truck, ending with a 175A Anderson plug. Ran 4 AWG from the trailer tongue to a power post in the trailer near the DC-DC charger, then dropped to 6 AWG to the charger. I have a Victron Orion 12/12-30 charger and have seen as high as 32A output to the batteries.

The Victron has an automatic engine detect feature, so there's no need for switches. Once the batteries reach 100% SOC, the charger automatically switches to float mode, there's no need to manually control it.

 

[BuckeyeF350]

I would run a dedicated circuit and get the best performance out of your DC-DC charger, instead of depending on undersized wire both in the truck and trailer.

I ran a dedicated 4 AWG circuit to the back of the truck, ending with a 175A Anderson plug. Ran 4 AWG from the trailer tongue to a power post in the trailer near the DC-DC charger, then dropped to 6 AWG to the charger. I have a Victron Orion 12/12-30 charger and have seen as high as 32A output to the batteries.

The Victron has an automatic engine detect feature, so there's no need for switches. Once the batteries reach 100% SOC, the charger automatically switches to float mode, there's no need to manually control it.

Yeah, it doesn't look like the BMC option will work how I wanted it to work.

Did you use a bracket for the Anderson connector on the receiver? I like that install.

Also, what do you do with the charge cable if you don't need it? Or do you just always plug it in?

 

[01tundra]

Yeah, it doesn't look like the BMC option will work how I wanted it to work.

Did you use a bracket for the Anderson connector on the receiver? I like that install.

Also, what do you do with the charge cable if you don't need it? Or do you just always plug it in?

Drilled and tapped two small holes in the bottom of the receiver and used an aluminum spacer plate to get the plug where I wanted it. Ran two stainless steel bolts through the two mounting holes on the Anderson plug.

Here's my go-to source for Anderson hardware and tools:

https://powerwerx.com/dc-power-products

Wire:

https://www.amazon.com/gp/product/B01MY9V9M5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Lugs:

https://www.amazon.com/gp/product/B073Y74YR2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

The 12V+ from the truck only powers our TPMS signal booster and rear view camera now.

Here's the power wiring diagram I made for our trailer -

 

[01tundra]

I've seen several cases of people trying to used the factory truck wiring to power their DC chargers and every one of them were not getting near the rated output out of them.

With our previous Victron 12/12-18 I would regularly see 25A to the batteries while in absorption mode. I've seen as high as 32A out of our new 12/12-30.

I'm currently seeing around a 0.6V drop from the truck battery to the DC charger. Not bad for a 25' circuit length on the truck and probably 10' from the tongue to the batteries.

Took me maybe 15 minutes to route the power wire along the passenger side frame rail. The wire is in expandable plastic sheath, then that is in plastic loom, then fully wrapped from one end to the other with cloth loom tape.

This time I picked up the 12V- for the truck at a chassis ground at the back and added a second 4 AWG chassis ground from the battery up front.

 

[BuckeyeF350]

With Victron releasing their new 50A DC-DC charger, I think I'm going that route. I'm also considering going with two of them. We have 400ah of Battle Born batteries, and the '397 amp alternator' option. Anyone see any issues with me installing two of those 50A chargers?