Installing a DC-DC Charger: 50 A

[Tscottok]

Hey MTC,

I'm planning on installing a DC-DC charger in the mav, so I can recharge my trailer battery while driving. There a few questions/satiny checks I'd love some help with, and cheers if others have considering the same thing!

The plan to go with the Victron Orion XS DC-DC charger since it's smaller, doesn't run as hot, and lets you customize a specific per amp battery charge rate (up to 50A). Below is a wiring diagram and a walk-through of the system.

Please let me know if you have any thoughts and/or input on the questions.
Thanks!


Main Questions:
Confirming the output of the "high-output" alternator is 175 amps

This is the one for trucks with 120V outlets in the cab/bed​

I found LX6Z10346E as the right part number, giving a rating from this Ford parts page​

How "bad" would it be to run 50A with the below setup?

Only when rpms stay high so it doesn't overheat (restrict changing at idle: helpful video for charging with alternators)​

It would still be running semi-continuously for up to 4 hours to fully charge my battery​

Please let me know if you have a recommendation for a better amperage to set in the charge controller​

Any preferred spots to run a thin, signal wire from the driver's side dash into the engine bay?

Small ~16 AWG from the on/off button for the relay​

Is it worth it to ground the negative cable between the charge controller and trailer plug? (wiring diagram)

My thought, is that it helps balance any voltage potential between the negatives of the truck chassis and trailer frame. Plus, it couldn't really hurt.​

However, the trailer coupler and truck hitch could already accomplish this already, ignoring whatever interference from the grease...​

What am I missing?

Just looking for a 2nd set of eyes and sanity check before I get started.​

The Details:
Starting at the Truck's battery...

1. 60 A terminal fuse on the battery's positive bus
2. 4 AWG marine grade, tinned copper cable (used everywhere)
3. Sealed, UL Rated 100A continuous duty relay (normally open) mounted near the battery in the engine bay
4. Relay activated via a push button on/off switch in the truck cab. It stays "on," even after pit stops.
   - The truck battery hopefully won't die since the switch will only be powered when the engine is running; via a fuse splitter inside the cab's fuse box
5. Cable goes from the from the relay, under the truck, and to the cubby in the truck bed
6. A Victron Orion XS DC-DC charge controller is mounted in the truck's cubby. They're smaller and run cooler than a 30A system (with a steep cost bump)
7. This is connected to a 120A Anderson plug mounted near the hitch
8. The trailer side of the plug is connected to the battery (positive) and the frame/shunt/battery (negative)

Wiring Diagram:

Thanks for any help!

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[The Real Maverick]

Seems way "overkill" and a spend of money you don't need to spend money on.

Seems INSANE to me.

 

[The Real Maverick]

I forgot to ask are these LiFePo batteries in the trailer?

or What type of batteries in this trailer?

 

[Tscottok]

230 amp LiFePo batteries.

Originally, I bought a 20 A charger that plugs into a standard house 120v plug. I was planning on charging right out of the provided plug in the bed while driving, then direct to the trailer if/when I had a hookups.
20 A at 14.5 V is 290 W, so it should work with the 400W rated maverick plug, right.....

Except, the trucks aren't built for that. The charger powers up, begins to charge, then overloads the mav's system and trips the breaker after ~3 seconds. Even, while driving.
What's nice, the truck's breaker auto-resets after ~25 seconds so you don't have to do manually flip anything. Then process this process repeats.

Next, I downgraded the smaller 10 A charger and it works fine. But the output of that thing is ~7.5 A and it takes FOREVER to charge. We boondock a lot and want a way to charge between locations. Especially in winter, where we run pipe heaters if it drops below 32F. We do have solar, but only ~240W and doesn't keep up if we run the inverter


Which brought me to this project. A DC-DC charger is still the best option for charging from a vehicle. There's no need to go from 12 V to 120 V then back to 12 V to charge a the battery.
Victron has the best tech, and I'm already using them for the solar & shunt. I was going to get there 30 A version (probably better matched), but it runs really hot and is massive (it needs a heatsink).
Plus, it doesn't let you define the charge rate amps like the 50 A model. I'm hoping that'll let me charge my trailer when the truck is idling since I can cap the max amp. It'll let us stay camped out in remote locations or at a festival.

That's what brought me here,
if I'm going with the 50 A model, could the damn thing even handle 50 A? (if wired correctly)
And how can I fully turn off/isolate the system with a push of a button?

 

[Rparry]

Tscottok:

We are trying to do similar things, mine will be in a Hybrid and onboard not on a trailer. I am looking to something similar with the battery either under the seat or in the bed. The DC-DC
charger would be as close to the main battery as possible and charge the battery with the
inverter at the battery.

 

[MinnesotaMatt]

I'm sorry I can't help answer your question but I was considering doing something similar. I was looking at the Bluetti Charge 1. I was planning on setting it up in the bed of the truck and plugging it into a Bluetti AC200L which has a camper plug. I figured we would start by seeing how much use we can get out of the house batteries (2 100 Ah LiFePO4) on the camper and also plugging in the camper to the AC200L (2048 Wh). Bluetti also sells the D40 which will allow you to recharge the house batteries directly.

My thought is if we park our trailer, we can still charge the AC200L while we are out sightseeing for the day.

Answer to the questions you asked above would be of interest to me. Also, I haven't looked at what path I would take running the wire from the car battery to the bed. Any thoughts or links to videos on that wold be interesting to me.

Thanks,

Matt

 

[Rparry]

I used an EcoFlow Delta 3 with their 800 watt alternator charger on my 2025 Hybrid. During my trip from coast to coast and back it worked a charm.

I originally wanted to connect to the under hood battery connections but the cable was a bit short. So I went to the battery.

If you are using high wattage devices like the induction hot plate I would turn the ignition ON and when it needed to charge the truck would cycle the engine on an off.

We might be getting a Teardrop to add to the RTT that I used. I would then run an extension cord to the trailer to run what ever we wanted on the trailer.

This has been a near perfect solution to my power needs while on the road.

BP

 

[Tscottok]

Hey All,

I ended up installing the DC-DC charger in the cubby and, putting a plug/cover near the license plate (pics below). I really liked Victron's 50A charger because it runs a lot cooler than their 30A (more efficient), and the app lets you customize the exact in/out amperage.

I've tested the setup a few times, but only run at ~35 amps while driving and 10-15 while at idle. I'm pretty sure these high-output alternators are rated for 175 A, so I'm hoping this won't overload anything.

I also installed a normally open relay with a switch in the cabin. This is so I can de-energize the entire system downstream of the engine bay, and it auto-shuts off when I turn off the car. The charger is supposed to have engine running detection, but figured this was safer so I don't accidentally drain the battery. Just wired the on switch to the fuse box, and went through the rubber opening in the dash


Installed charger:

Plug on back

Relay (switch is in the cabin)

 

[laneli]

Hey! I'm planning to do the same thing (minus the plug since my leisure battery is in the truckbed). Could you explain/show how you routed the cables from the hood to the cubby and what you grounded to? What length did you end needing (I see you estimated 15ft initially)?
Thank you!

 

[Pstewone]

Hey All,

I ended up installing the DC-DC charger in the cubby and, putting a plug/cover near the license plate (pics below). I really liked Victron's 50A charger because it runs a lot cooler than their 30A (more efficient), and the app lets you customize the exact in/out amperage.

I've tested the setup a few times, but only run at ~35 amps while driving and 10-15 while at idle. I'm pretty sure these high-output alternators are rated for 175 A, so I'm hoping this won't overload anything.

I also installed a normally open relay with a switch in the cabin. This is so I can de-energize the entire system downstream of the engine bay, and it auto-shuts off when I turn off the car. The charger is supposed to have engine running detection, but figured this was safer so I don't accidentally drain the battery. Just wired the on switch to the fuse box, and went through the rubber opening in the dash


Installed charger:

Plug on back

Relay (switch is in the cabin)

Looks good. They the Orion XS run cool compared to the older models. I use the older model. Is that a Schrader valve next the the Orion? Do you have air-bags. If so, how do you like them?

 

[Harnjohn]

I used an EcoFlow Delta 3 with their 800 watt alternator charger on my 2025 Hybrid. During my trip from coast to coast and back it worked a charm.

I originally wanted to connect to the under hood battery connections but the cable was a bit short. So I went to the battery.

If you are using high wattage devices like the induction hot plate I would turn the ignition ON and when it needed to charge the truck would cycle the engine on an off.

We might be getting a Teardrop to add to the RTT that I used. I would then run an extension cord to the trailer to run what ever we wanted on the trailer.

This has been a near perfect solution to my power needs while on the road.

BP

Hello I am thinking about installing same setup on my 2024 Hybrid what you suggest any problem so far... you still use it or stop using it?

 

[Cherokee]

Somebody is gonna set a Mavrick on fire !
Izzat an old school start solenoid I saw ?

 

[Pstewone]

Hello I am thinking about installing same setup on my 2024 Hybrid what you suggest any problem so far... you still use it or stop using it?

I used mine for two camping in the summer of 2025 (total of 10 weeks) with no issue. There is another thread with better information you should look at. My setup components, Victron Orion 18 amp DC-DC charger. 100ah LifePo4 and a compressor frig/cooler wire and fuse etc.

 

[Harnjohn]

Somebody is gonna set a Mavrick on fire !
Izzat an old school start solenoid I saw ?

Thank you for your response.
I am planning to install ecoflow 800 alternator on 2024 hybrid truck directly 12v battery to charge my ecoflow delta 3 max plus. I seen someone already using it picture attached

 

[Rparry]

Hello I am thinking about installing same setup on my 2024 Hybrid what you suggest any problem so far... you still use it or stop using it?

I used it for my cross Canada trip and it worked perfectly. I have not had the Power Station in the truck since I got back but the Charger has remained in the truck with no issues.

I found that I could use the charger while using a high power load such as my inductive hot plate at the same time. The inductive hot plate would take around 1000 watts and the charger would make up 800 watts, so there was very little draw down over breakfast. I would just turn the truck on and it would cycle the engine off and on as the power station required. Worked great. Interestingly plugging the Power Station into 120 volts while using the Hot Plate it overloaded and stopped. I guess the inverter was not large enough to charge at 1500 watts and run the hot plate.

For next years camping season, as this will involve my Grand Kids and their family, I might add an extra battery to the system as they will use more energy than just their Grandpa. My kids are kinda Foodies so will use it more than I did on the trip.

BP

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