Generator carrier with bike rack used in 2" Receiver hitch

[montana-todd]

Hi all,
We recently downsized from a Momentum 350G to a Reflection 150. While the layout and overall size of the Reflection 150 Bunk House work better for our family (a 3 and 6 year old) boondocking in National Forest and BLM spots with a shorter length, I find it's been a lot tougher to streamline mechanically without the onboard generator.

I have a Cummins Onan P4500i generator that use to augment our solar and 800 amp hours of batteries. As of now, I keep it in the rear storage bay, then drag it out and hook it up when I need it. I'd love to have it mounted on some sort of tray. Ideally, I'd like the following.

1) The ability to run the generator while moving if it's hot. I.E. start it up and turn on the AC at the last stop before we arrive at our destination.
2) Not have to lug it in and out of the 5th wheel when we reach a site. The proximity to the rear window may cause a CO2 alarm in the generator. However, if it's externally mounted, it's much easier for me to take off the mount and wheel out and perform contortionist heavy lifting behind the bike rack.

Below are some pictures of the rear of my trailer. You can see the vertical bike rack for our e-bikes takes up quite a bit of space. Given the weight of the bike rack and the bikes (nearly 300lbs), I don't want to add a receiver extension with a tray, since this will likely cause failure of the hitch due to exceeding the weight rating of the hitch. I'm trying to work around this issue. I've considered a sliding tray on the side of the 5th wheel on the driver's side near the Nautilus control panel, but that doesn't meet the requirement of running while towing. Any suggestions/implemented solutions would be very helpful!

 

[jkwilson]

Having 300 pounds that far off the back of your trailer probably already greatly exceeds the capacity of the receiver, so I think you can dismiss the idea of using that right off the bat. The moment arm magnifies the force a lot.

 

[Soundsailor]

Agree with [MENTION=10506]jkwilson[/MENTION], you're already at or near the capacity of the rear receiver, no room for more there without beefing things up. We have a smaller generator that rides in the truck bed.

As far as running the AC when hot, with 800 Ah of battery you could run the AC with an inverter. For our system, 1 hour of AC eats up about 125 Ah of battery. You could get a couple of hours in and still have quite a bit of battery capacity left.

 

[montana-todd]

Hi all,
You're correct about using the AC with an Inverter. We have 2 AC units (we installed a small one in the master), and I can run both on Low Auto with our 3000W Go Power inverter. However, I've had a couple of instances where we get into the national forest campground later in the day, after quiet hours. At that point, we're down to about 50% battery due to the ACs running continuously for 2-3 hours. I've found our inverter reaches the low power cutoff point and shuts down while we're asleep.

Ideally, I'd like to be able to run the generator until we get close to our destination, then we'll have all the battery capacity saved for the night, and we'll also have a pre-cooled RV, so we'll use less power to maintain the temperature.

Your "generator in the truck" comment does give me an idea! Has anyone installed a second additional 50 amp plug into the front of their 5th wheel? I'm curious if I could add one, and then simply just leave the generator locked up in the truck bed and run it while we drive.

As an alternative to the generator in the truck, I've considered adding a heavy-duty 4/0 gauge wiring harness to my GMC 3500, and then plugging that into the trailer to use the alternator to feed power in while driving and using the inverter. However, I just don't think I'd generate enough power when compared to running the generator.

 

[Soundsailor]

How about a DC to DC converter? A 40 Amp unit should handle the AC just fine.

 

[uwskier]

If this would work from a clearances perspective, it reduces your concern over excessive leverage on the receiver.

 

[jkwilson]

If this would work from a clearances perspective, it reduces your concern over excessive leverage on the receiver.

View attachment 46452

That will make the problem much worse.

 

[montana-todd]

That's a really good question. I called GM today, and I have a 220 amp alternator in my truck, so I should have plenty of amps to spare.

I've been researching DC to DC converters vs charge controllers. From what I can gather, if I use a DC to DC converter, I'd have to isolate it to only go directly into my inverter.

I've read that DC to DC converters should not be hooked directly to my AGM batteries, because it can damage them after they're 80% charged.

If I go with a charge controller, such as this Victron one, I can still supply power at 40A (which really seems to be 420W sustained /12 v= 35.83 amps in the spec sheet) with the bulk mode, but then slow to absorption and float charging without damaging my batteries.

If I've done my math correctly, my Onan P4500i supplies 30.8 amps continuously at 120V. This means that if I'm getting 35.83 amps at 12v DC out of my truck, I'll actually get more power into my bank than if I were to run the generator in the bed. Not only is DC higher amperage on the surface over AC from the generator, but it also doesn't take into account the loss when converting from AC to DC.

Does this seem correct, or did I calculate something incorrectly?

 

[Soundsailor]

This (https://www.amazon.com/gp/product/B07Q4SVX3M/) is the charger we have, it is compatible with AGM batteries. You would need a connection from your alternator.

 

[Boom 'r Bust]

You can install a 50A ATS (automatic transfer switch) and put a 50A outlet on the front of your rig. Then plug the generator into that.

Turn off your converter circuit breaker when doing this. That and your AC might be too much.

 

[powerscol]

Hi all,
We recently downsized from a Momentum 350G to a Reflection 150. While the layout and overall size of the Reflection 150 Bunk House work better for our family (a 3 and 6 year old) boondocking in National Forest and BLM spots with a shorter length, I find it's been a lot tougher to streamline mechanically without the onboard generator.

I have a Cummins Onan P4500i generator that use to augment our solar and 800 amp hours of batteries. As of now, I keep it in the rear storage bay, then drag it out and hook it up when I need it. I'd love to have it mounted on some sort of tray. Ideally, I'd like the following.

1) The ability to run the generator while moving if it's hot. I.E. start it up and turn on the AC at the last stop before we arrive at our destination.
2) Not have to lug it in and out of the 5th wheel when we reach a site. The proximity to the rear window may cause a CO2 alarm in the generator. However, if it's externally mounted, it's much easier for me to take off the mount and wheel out and perform contortionist heavy lifting behind the bike rack.

Below are some pictures of the rear of my trailer. You can see the vertical bike rack for our e-bikes takes up quite a bit of space. Given the weight of the bike rack and the bikes (nearly 300lbs), I don't want to add a receiver extension with a tray, since this will likely cause failure of the hitch due to exceeding the weight rating of the hitch. I'm trying to work around this issue. I've considered a sliding tray on the side of the 5th wheel on the driver's side near the Nautilus control panel, but that doesn't meet the requirement of running while towing. Any suggestions/implemented solutions would be very helpful!

View attachment 46443
View attachment 46444
View attachment 46442

The Reflection frame is the issue - it is very weak. You will need to get it reinforced at the back to take the weight of what your trying to do. Inquire around at your local welding shops for help on how to reinforce everything. The receiver hitch is only welded to the cross member at one point and that is the weak point. The other weak point is where the receive assembly is bolted to the frame web on both sides - not much strength there. How do I know - I had at least 8 cracks develop in my frame over the suspension points and I am closely watching my rear spare tire carrier, receiver style.

 

[Tom Traveler]

That's a really good question. I called GM today, and I have a 220 amp alternator in my truck, so I should have plenty of amps to spare.

I've been researching DC to DC converters vs charge controllers. From what I can gather, if I use a DC to DC converter, I'd have to isolate it to only go directly into my inverter.

I've read that DC to DC converters should not be hooked directly to my AGM batteries, because it can damage them after they're 80% charged.

If I go with a charge controller, such as this Victron one, I can still supply power at 40A (which really seems to be 420W sustained /12 v= 35.83 amps in the spec sheet) with the bulk mode, but then slow to absorption and float charging without damaging my batteries.

If I've done my math correctly, my Onan P4500i supplies 30.8 amps continuously at 120V. This means that if I'm getting 35.83 amps at 12v DC out of my truck, I'll actually get more power into my bank than if I were to run the generator in the bed. Not only is DC higher amperage on the surface over AC from the generator, but it also doesn't take into account the loss when converting from AC to DC.

Does this seem correct, or did I calculate something incorrectly?

If I’m reading this correctly, you are missing the fact that it’s watts that count, not amps. (Watts = amps x volts). The Onan is giving you 4,500 watts, more than 10 times the power from the Victron. For the typical RV air conditioner you need about 12 amps at 120v, not counting starting current. That is 1,440 watts or more than 3 times what you can get from the Victron. It will help a bit but will not come close to powering an air conditioner.

I like the idea of running the generator in the truck bed if it can be done safely.

 

[montana-todd]

Thanks for the reply [MENTION=44988]Tom Traveler[/MENTION]. That's a very good point on the Wattage. I do like the idea of having the generator in the truck, and then installing the same plug in the front as what's located in the rear of the trailer. I'd then run the line to the same converter as the rear inlet.

However, I'd like to install a breaker between the front 50 amp plug and the converter. This way, if I'm using shore power on the rear of the trailer, I can open the breaker and avoid having a live power in the plug at the front of the 5th wheel. Any ideas on what type of breaker to install?

 

[Tom Traveler]

Thanks for the reply [MENTION=44988]Tom Traveler[/MENTION]. That's a very good point on the Wattage. I do like the idea of having the generator in the truck, and then installing the same plug in the front as what's located in the rear of the trailer. I'd then run the line to the same converter as the rear inlet.

However, I'd like to install a breaker between the front inlet and the converter. This way, if I'm using shore power on the rear of the trailer, I can open the breaker and avoid having a live power in the plug at the front of the 5th wheel. Any ideas on what type of breaker to install?

That is a good catch. The receptacles on the RV will have "live" male prongs when using the other inlet plug. The same will be the case for the rear plug when you plug into the front with your truck bed genny. You could put a small breaker panel, with a 50 amp 2-pole breaker, by the front plug. You would still have a live rear plug when using the front plug, but that rear plug has a cap and you generally wouldn't be messing with it until you set up at a shore power site. Just make sure the generator is disconnected before you plug in shore power. This setup wouldn't comply with code, I don't think, because you wouldn't have a failsafe lockout. A goof up could be fatal.

Another option, the best one from a safety and simplicity standpoint, would be a 50 amp, 2 pole transfer switch. Both the front and rear plugs would feed the transfer switch and the output of the transfer switch would feed the converter. This is actually the common setup for a built-in generator.

They are not that expensive. https://a.co/d/dv7AmGR. This wouldn't cost much more than a breaker panel and might be an easier install. That's they way I would go.

 

[montana-todd]

The automatic transfer switch makes a lot of sense, I like that option. Thanks for this information! Our Momentum 350G had one, though I never had to deal with it. The generator had to run for about 30 seconds before it'd cut over to it for AC input.

Is there any brand that you'd recommend you've found superior to others when dealing with the vibrations of being in a travel trailer?

 

[huntindog]

Having 300 pounds that far off the back of your trailer probably already greatly exceeds the capacity of the receiver, so I think you can dismiss the idea of using that right off the bat. The moment arm magnifies the force a lot.

That much added weight on the rear can lighten the TW causing sway.
Don't ask how I know this.

 

[Tom Traveler]

The automatic transfer switch makes a lot of sense, I like that option. Thanks for this information! Our Momentum 350G had one, though I never had to deal with it. The generator had to run for about 30 seconds before it'd cut over to it for AC input.

Is there any brand that you'd recommend you've found superior to others when dealing with the vibrations of being in a travel trailer?

We have the one in my link and have had no issues. I don't have any experience with any others.

 

[Boom 'r Bust]

The automatic transfer switch makes a lot of sense, I like that option. Thanks for this information! Our Momentum 350G had one, though I never had to deal with it. The generator had to run for about 30 seconds before it'd cut over to it for AC input.

Is there any brand that you'd recommend you've found superior to others when dealing with the vibrations of being in a travel trailer?

I went with the GoPower 50A ATS. It's a little more money but uses a metal case and higher qualty components. Plus it's a very simple install.

 

[jlk111]

Your "generator in the truck" comment does give me an idea! Has anyone installed a second additional 50 amp plug into the front of their 5th wheel? I'm curious if I could add one, and then simply just leave the generator locked up in the truck bed and run it while we drive.

I installed a 30 amp plug in the front of our 2500RL. Ran a 10 gauge wire in conduit (was able to remove a few screws holding the coroplast up at both ends to feed conduit above coroplast) to a mechanical transfer switch mounted next to the electrical panel inside trailer. I can switch from front or rear plug as needed. On our desert lot I leave the generator in the pickup and plug it in when we come back to the trailer for the night. I don't have to worry about the generator disappearing while we are away. I run our Honda eu3000 in the canopy with the door opened up, it really cuts down on the engine noise. When the canopy is not on the truck I have ran the generator while driving and it works really good. Secure the cord really well. You could do the same with a 50 amp setup.

 

[kb0zke]

Remember that a generator needs oxygen to run and produces carbon monoxide in the exhaust. This "breathing" involves far more than meets the eye. After an ice storm took out ALL electricity in the county I bought a generator and built a garage for it (well, garage, shop, and generator area). I had two two-foot-square openings in the generator area, so I thought I had plenty of airflow. Wrong! In 15 minutes the generator was out of oxygen and the generator area of the building was full of exhaust. In order to actually use the generator I had to drag it out onto the deck.

Back when we had that S&B and generator I thought about putting the generator in the truck and powering the a/c that way while driving. We ended up buying a motor home that had a generator designed to power the two air conditioners, so I kind of forgot about that idea until this thread came up.

The other thing to think about is that generators aren't exactly light. Will you have enough rear axle weight capacity to handle another couple hundred pounds in the bed? Yes, you could get a smaller one that will power only one a/c, but then it is easier for someone to take it for a walk.