Can a trailer be powered through the 7-pin plug on the Mav hybrid?

[chilicharger]

Like the title says, can a travel trailer be powered or the trailer batteries charged through the 7-pin trailer harness hookup? Since the hybrid can start the engine to charge when it detects the truck battery getting low, it makes me think it would be pretty useful when you stop for the night and don't have hookups at an RV park or whatever.

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[scharris99]

Pin 4 is 12 volt power and should be hot while driving. Not sure how long it stays hot when off.

 

[rk06382]

I do not have a travel trailer, but my understanding is you will need a DC2DC charger to raise the 12v from the 7-pin to charge your trailer battery. There is also limit of 20 amps from the 7-pin.

From Forest River forum:
Search results for query: dc to dc 7-pin

Example from Amazon:
Victron Energy Orion-Tr Smart DC to DC Charger (Bluetooth) - 12/12-Volt 18 amp

 

[Maverick123]

I did exactly that, but differently - I used a Noco Genius 10 10a charger plugged into the bed's 120v outlet to power our trailer when its battery started going bad.

"Start" the truck ('Ready' mode), disable the 30 minute timeout through the dashboard control, and it'll charge the trailer battery and power the trailer as long as you don't turn off the ignition. 10 amps isn't much but it was OK in our case to run the fan, lights, water pump, etc

I had to leave a key fob inside the truck and lock the door with the physical key while it 'ran'. The ICE would cycle on and off as needed. Maybe there's a way to do something similar with the flexbed's 12v outlet but I don't have anything wired to that yet

 

[chilicharger]

I did exactly that, but differently - I used a Noco Genius 10 10a charger plugged into the bed's 120v outlet to power our trailer when its battery started going bad.

"Start" the truck ('Ready' mode), disable the 30 minute timeout through the dashboard control, and it'll charge the trailer battery and power the trailer as long as you don't turn off the ignition. 10 amps isn't much but it was OK in our case to run the fan, lights, water pump, etc

I had to leave a key fob inside the truck and lock the door with the physical key while it 'ran'. The ICE would cycle on and off as needed. Maybe there's a way to do something similar with the flexbed's 12v outlet but I don't have anything wired to that yet

Thanks for that feedback! I already have several Noco chargers, so I can do that immediately. Did you track how often the truck would turn on? How long would it stay on the charge the battery?

 

[Maverick123]

Thanks for that feedback! I already have several Noco chargers, so I can do that immediately. Did you track how often the truck would turn on? How long would it stay on the charge the battery?

No I didn't track it, but it didn't start often nor did it run for very long when it did. It's been a while but I'd say maybe a minute or two every 40 minutes? It was definitely 1000% quieter than having a generator blaring. You'd barely notice it.

Oh BTW when I did this I was unhitched and the truck was parked about 20 feet away at an angle. If you do this while hitched, you want to be 100% sure your carbon monoxide detector is functional ... also maybe back it up a bit jackknifed to avoid the exhaust pointing straight at your trailer

 

[Ranko Kohime]

If your trailer is appropriately wired, then the 12 V line from the truck should charge the house batteries in the trailer while driving down the road, however, I think you will find the juice is not worth the squeezing when it comes to running overnight, as it won’t transfer enough power to run an AC or any other heavy power draw.

Additionally, the idle fuel consumption is rather high, at nearly 1.5 gallons per eight hours.

 

[Ranko Kohime]

I had to leave a key fob inside the truck and lock the door with the physical key while it 'ran'.

I think you will find that if you ignore the “no key detected” message, that you can just take the key with you and lock the door as normal with it in ready mode.

 

[Mavster Mechanic]

I do not have a travel trailer, but my understanding is you will need a DC2DC charger to raise the 12v from the 7-pin to charge your trailer battery. There is also limit of 20 amps from the 7-pin.

From Forest River forum:
Search results for query: dc to dc 7-pin

Example from Amazon:
Victron Energy Orion-Tr Smart DC to DC Charger (Bluetooth) - 12/12-Volt 18 amp

Since I added my 7-pin after dealer deliveryI have 30 amps and plenty of volts. (Like 14.7v).

The charge controller is in the RV as standard equipment in most.

Works great. No fancy extra equipment for me to buy.

And yes. You COULD leave the truck to "run" for as long as you have gas.

I have considered this to be my backup system if I run out of trailer juice while off grid. My TT currently has 300 amp hours available. Have yet to use even half of that in a 2 nights 2 days off grid.

 

[Maverick123]

I think you will find that if you ignore the “no key detected” message, that you can just take the key with you and lock the door as normal with it in ready mode.

You're probably right, I'll have to try it sometime. But in this instance I didn't want to disturb the other campers with the double honk

 

[Mavster Mechanic]

No I didn't track it, but it didn't start often nor did it run for very long when it did. It's been a while but I'd say maybe a minute or two every 40 minutes? It was definitely 1000% quieter than having a generator blaring. You'd barely notice it.

Oh BTW when I did this I was unhitched and the truck was parked about 20 feet away at an angle. If you do this while hitched, you want to be 100% sure your carbon monoxide detector is functional ... also maybe back it up a bit jackknifed to avoid the exhaust pointing straight at your trailer

Good general advice about carbon monoxide when using a traditional gas vehicle.

With a hybrid, no worry.
You said it yourself:

2 minutes of engine run followed by 40 minutes of fresh air.

Repeat indefinitely.

 

[rk06382]

Since I added my 7-pin after dealer deliveryI have 30 amps and plenty of volts. (Like 14.7v).

The charge controller is in the RV as standard equipment in most.

Works great. No fancy extra equipment for me to buy.

And yes. You COULD leave the truck to "run" for as long as you have gas.

I have considered this to be my backup system if I run out of trailer juice while off grid. My TT currently has 300 amp hours available. Have yet to use even half of that in a 2 nights 2 days off grid.

I have 600 amp hours with six Battle Born batteries in my Class A FR3 DS28 . How many batteries do you have to get 300 amp hours?

Solar Power & Battle Born batteries

 

[chilicharger]

Since I added my 7-pin after dealer deliveryI have 30 amps and plenty of volts. (Like 14.7v).

The charge controller is in the RV as standard equipment in most.

Works great. No fancy extra equipment for me to buy.

And yes. You COULD leave the truck to "run" for as long as you have gas.

I have considered this to be my backup system if I run out of trailer juice while off grid. My TT currently has 300 amp hours available. Have yet to use even half of that in a 2 nights 2 days off grid.

What all do you run with that 300 amp hours available and not even drain half of it in 2 whole days? I assume ACs are not able to be run off batteries. What kind of trailer do you have? Pics?

 

[Mavster Mechanic]

I have 600 amp hours with six Battle Born batteries in my Class A FR3 DS28 . How many batteries do you have to get 300 amp hours?

Solar Power & Battle Born batteries

Three LiFePo batteries.
Looks like 100 Ah batteries are a common item.

Three were preferable in my case vs. one large. In my battery box I have space for two North & South and one East and West. Also three are easier to lift and place. Like an amazing 17 lbs each I think they are.

 

[Mavster Mechanic]

What all do you run with that 300 amp hours available and not even drain half of it in 2 whole days? I assume ACs are not able to be run off batteries. What kind of trailer do you have? Pics?

Everything but Air Conditioning.

I have also a 3000w inverter.
Could run the Air Conditioning.
For an hour or two!

TV (Intermittent use.)
Microwave (very intermittent use).
Cabin lights.
Electric heat (on mild nights)
Blower for propane heat (on really cold nights)
Water pump.
Water heater (very intermittent use)
Water heater is propane fired but has 12v electronics and 12v electric to start it.
12v Dorm Room size fridge.

Radio / tablet / phone chargers.

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