Pro Power Onboard Generator 7.2K Powering a Trailer While Driving -- IT WORKS!

[Ron in Oregon]

When we wash and winterize our trailer in a week or two I'll take some pictures for you. The shore power inlet is at the rear-quarter on the drivers side. However, I have bypassed the trailer's as-built shore power inlet completely. The AC breaker panel (& DC fuse panel) are underneath the stove/oven midway on the passenger side. From the yellow connector on the trailer tongue (see pictures in my OP) the power cord runs along the frame and up the same hole as the propane line to the stove. All I had to do was gouge out some spray in foam sealer and push the cable up along the propane line, then spray in some new foam crack sealer. I disconnected the as-built shore power line from the AC breaker box and connected my new cable in it's place. If we are at an RV park we now run the power cord from the RV park pedestal to the yellow connector on the tongue of the trailer.

The PPoB will run the AC just fine - it has plenty of juice! However, being our only outing with this new setup was just last week and we are in the Pacific NW there was no need for the AC this time around. As you can see in the last photo in my OP we were feeding the trailer 1300 watts (battery charger & fridge) while running down the road - which still leaves 2300 watts available!

I think I'm going to name the truck PowerBeast! ?

-Eric

Nice job! I would like to do this for our trailer. Reading another owner's project, he put in a 'transfer switch' , providing an automatic switch between the shore power OR Powerboost cable. I would appreciate if you could provide part numbers and sources for your cables and connectors. Thanks!

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[EricR]

OK, per request here is what I did to get the 120V 30A power inside the trailer.

It was easier than I had expected.

 

[EricR]

 

[EricR]

 

[EricR]

 

[EricR]

Nice job! I would like to do this for our trailer. Reading another owner's project, he put in a 'transfer switch' , providing an automatic switch between the shore power OR Powerboost cable. I would appreciate if you could provide part numbers and sources for your cables and connectors. Thanks!

Actually, my early design iterations included a transfer switch - and I even bought (and returned) one. Then the light bulb went on and I realized I was making things harder than necessary. Shore power from a RV park pedestal can simply connect to my new power cord's connector up on the tongue.

Now all 120V power now comes to the trailer from the front, be it PPoB, RV park shore power, or even an extension cord from my house. Our RV's original shore power inlet is (as explained in the pictures) is disconnected from the trailer's AC breaker box and is no longer used.

For that first trip I used the same shore power cable that we have always used. I just connected to the new connector on the tongue instead of original one on the side of the trailer. For next spring I will make a longer shore power cord (say 40 feet) using another of the watertight connectors.

Stay tuned, I'll also post a Bill of Materials.

Hope all this makes sense!

-Eric

 

[UGADawg96]

Really appreciate you posting these. Good quality images and explanations. Makes it easy to follow along and use as a guide.

 

[EricR]

The L14-30P connector that plugs into the PPoB has 4 pins (ground, neutral and 2 hot leads). However if your trailer has 30 Amp service like ours, you would only use 1 of the hot leads of the L14-30P as the power cable has only 3 conductors. In other words, connect the ground wire to the ground lug, neutral wire to neutral lug, and the hot wire to only 1 of the 2 hot lugs. The second hot lug goes unused.

If your trailer has 50 Amp service I believe you would use a 4 conductor wire - however I didn't research 50 Amp so you will need to do so yourself.

 

[EricR]

The attached spreadsheet lists materials and tools I used for this project.

Summary:

$154 - Parts Used​

$128 - Tools Bought (that I didn't already have) + Misc.​

----​

$282 - Total Spend​

Actually I spent a little more than that - the spreadsheet only accounts for the 10/3 SOOW cable actually used (not the entire 50 FT I bought).

-Eric

 

[cghall77]

Did you notice a difference in fuel mileage running your trailer while driving?

I like the idea even if I only have 2kw. I think I would still go with the transfer switch though. A couple weekends back I was 75ft from the pedestal and that was with my power being in the back driver side. If I had to connect to my tongue like yours that would be another 25ft I would have to run. Might as well make use of the wiring that is already there.

It has been very painful to find someone locally just to install 2 outlets and a breaker in our new trailer. Dealerships say they don't do this sort of thing and mobile rv guys say they are too busy to take on the work. Lol. Must be nice. Will probably do all the work myself in the spring.

Nice work.

 

[EricR]

Did you notice a difference in fuel mileage running your trailer while driving?

I like the idea even if I only have 2kw. I think I would still go with the transfer switch though. A couple weekends back I was 75ft from the pedestal and that was with my power being in the back driver side. If I had to connect to my tongue like yours that would be another 25ft I would have to run. Might as well make use of the wiring that is already there.

It has been very painful to find someone locally just to install 2 outlets and a breaker in our new trailer. Dealerships say they don't do this sort of thing and mobile rv guys say they are too busy to take on the work. Lol. Must be nice. Will probably do all the work myself in the spring.

Nice work.

Nice looking rig!

We didn't go out with the new truck until after I upgraded the trailer with lithium batteries and the new 120V run from the trailer. It's a great idea that would be a good MPG data point!

Wow, 75 feet. The shore power cable that came with the trailer is 25 feet, so in your situation we wouldn't have reached the RV park pedestal anyway. Before we go out again next spring I will build a 40 foot extension cord to help cover the additional distance to the tongue.

I really debated with myself about a transfer switch. A significant factor was were to put it. I hoped to put it behind the WFCO power center - but all of the wires, water, and gas lines there meant it wasn't possible. I also considered other places on the trailer for a transfer switch - but didn't see an easy way to do the cable run to those locations.

Then this super cool fact hit me:

No mater where we are or what the situation is - as long as we have gas in the tank - we can simply connect to the truck's PPoB - and have all the power we need!​

​

Soon I'll write up the trailer mods and provide a link. As a bit of a spoiler the trailer now has two 105 AH lithium batteries and a 60A battery charger. Just one hour of charging gives us enough power for 24 hours of 12V operation. If we somehow reach fully discharged (that would be at least 4 days without charging) they can be brought to 90% in less than 4 hours.

Even better, using the PPoB while we are driving means we always arrive at the next campsite with fully charged batteries.

It took a while to sink in. PPoB is brilliant! It erases power as a consideration - you are never without it. Now our focus has switched to fresh water and on the second trip we brought 5 extra 1 gallon water bottles to extend our boondocking duration. With this the grey water becomes our limiting factor.

The 60A charger never draws more than 1100 Watts so PPoB 2K should work just as well (though YMMV running the trailer's A/C).

As someone else on this forum said, you need to change your routine to filling up with gas before you reach your campsite, versus when departing in the morning as most of us typically do.

-Eric

 

[Ron in Oregon]

Nice looking rig!

We didn't go out with the new truck until after I upgraded the trailer with lithium batteries and the new 120V run from the trailer. It's a great idea that would be a good MPG data point!

Wow, 75 feet. The shore power cable that came with the trailer is 25 feet, so in your situation we wouldn't have reached the RV park pedestal anyway. Before we go out again next spring I will build a 40 foot extension cord to help cover the additional distance to the tongue.

I really debated with myself about a transfer switch. A significant factor was were to put it. I hoped to put it behind the WFCO power center - but all of the wires, water, and gas lines there meant it wasn't possible. I also considered other places on the trailer for a transfer switch - but didn't see an easy way to do the cable run to those locations.

Then this super cool fact hit me:

No mater where we are or what the situation is - as long as we have gas in the tank - we can simply connect to the truck's PPoB - and have all the power we need!​

​

Soon I'll write up the trailer mods and provide a link. As a bit of a spoiler the trailer now has two 105 AH lithium batteries and a 60A battery charger. Just one hour of charging gives us enough power for 24 hours of 12V operation. If we somehow reach fully discharged (that would be at least 4 days without charging) they can be brought to 90% in less than 4 hours.

Even better, using the PPoB while we are driving means we always arrive at the next campsite with fully charged batteries.

It took a while to sink in. PPoB is brilliant! It erases power as a consideration - you are never without it. Now our focus has switched to fresh water and on the second trip we brought 5 extra 1 gallon water bottles to extend our boondocking duration. With this the grey water becomes our limiting factor.

The 60A charger never draws more than 1100 Watts so PPoB 2K should work just as well (though YMMV running the trailer's A/C).

As someone else on this forum said, you need to change your routine to filling up with gas before you reach your campsite, versus when departing in the morning as most of us typically do.

-Eric

Thanks for sharing your mods. I assumed that the 'house' (trailer) batteries were charging when the trailer is connected to shore power. Is this not the case? I assumed there was already an inverter in the trailer, 120v to 12v, which recharges the house batteries. Did you add a 60 amp charger to recharge the house batteries faster? Is it on the 120v circuit?
Looking forward to your next write-up.
Thanks!
Ron

 

[EricR]

Seem' Erik's think a like, must be the Viking in us. Anyways, I do the same thing by running the Power cord that my camper came with for our 16 ft 2015 Shasta Airflyte Reissue, except I'm plugged into the main power at side of camper as I'm driving down highway with the heavy cord dangling at the side of camper. I know it sounds crazy. Works pretty good, does not drag on ground and I use those heavy duty twisty ties to attach to the tie down next to the 7.2KW generator plug and wrap around cord so it does not slip. I'm able to mostly keep my rollup bed cover closed as the cord exits the corner of tail gate and bed. Done this twice now on long trips of 2 plus hours to camp site. Keeps the refrigerator cold after giving it an overnight plug into the house the night before leaving on trip. Only thing is make sure you have enough slack so don't pop the connector on camper when making a tight turn to the right in my case since the generator and the camper receptacle are on the driver side of truck.

Erik

Hey Erik,

So you are using PPoB with no rewiring of the trailer - very cool! When you get a chance, a picture of your setup would likely be helpful to others wanting to do similar.

-Eric

 

[EricR]

OK, I have written up the changes I made to the trailer (including Lithium batteries) on diysolarforum.com where I learned much and received excellent feedback and advice!

https://diysolarforum.com/threads/u...o-conversion-–-compact-two-layer-build.32563/

Reply if you have thoughts, questions, or constructive criticism.

-Eric

 

[UGADawg96]

OK, I have written up the changes I made to the trailer (including Lithium batteries) on diysolarforum.com where I learned much and received excellent feedback and advice!

https://diysolarforum.com/threads/unique-travel-trailer-lifepo-conversion-–-compact-two-layer-build.32563/

Reply if you have thoughts, questions, or constructive criticism.

-Eric

Great write up! Thanks for sharing!

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