My Trailer Power System

[01tundra]

Since I've been studying all your posts over the months I figured I'd share what I ended up doing.

This is for a small travel trailer (22') being pulled with our 2017 GMC 2500HD for reference.....so not exactly "Expo", but relative to this forum section and I've paid my dues in expo stuff twice over .

The system consists of:

(2) Battle Born 100ah batteries
Progressive Dynamics PD4655L Wildcat converter
Victron SolarSmart 75/15 MPPT solar controller
Victron Orion-Tr Smart 12/12-18 DC-DC charger
Victron BMV-712
Renogy Eclipse 200W custom solar suitcase (wired in series)
Several Blue Sea breakers & power posts

First off, we're still tent campers at heart so when we're dry camping we typically only use around 10AH per 24 hr period, so we're very light power consumers since we're always outside. My ultimate goal is to be able to leave our Honda EU2200i generator at home. I installed a smaller DC charger because it will only be used for backup when we can't utilize solar. We always leave the house at 100% SOC and I have everything in the trailer switched and wired such that there is no measurable parasitic draw while traveling. If we're moving between spots there will always be a couple hour trip minimum, so the 18A charger should suffice.

The batteries are located inside next to the converter in the back of the trailer, connected with 1/0 positive/negative wires. Since the converter lugs wouldn't accept large wire, I landed the 1/0 on a power post and negative bar and ran parallel 6 AWG into the converter.

Backstory, we originally had two Trojan T-105 6V batteries in series up on the tongue, so the solar controller and DC charger are located in the front storage area. I had originally pulled 1/0 from the 6V batteries all the way back to the factory WFCO converter, so I repurposed the circuit to serve the solar controller and DC charger and went directly to the battery with a 50A breaker (bypassing the master battery isolation switch).

I ran dedicated 4 AWG from one of the truck batteries back to an Anderson 175A power plug mounted on the receiver hitch, using a Blue Sea 50A battery post fuse. On the trailer I ran a second pigtail with Anderson plug to the DC charger, the positive is ran thru a battery disconnect switch for manual control of the DC charger.

My 18A/280W DC charger was putting our 25A/346W so I had to upgrade a few breakers.....that's a good problem. I ran it for 15 minutes initially and the amp draw never dropped, I call Victron and the tech said that they have slightly underrated the output?

 

[dreadlocks]

This setup looks familiar, nice work..

My ultimate goal is to be able to leave our Honda EU2200i generator at home.

Yeah dont count on that, Ive got half as much battery as you and 3x as much solar as you, and still need the generator when the sun's not being cooperative.. Ive gotten it to the point where it gets used extremely little, especially here in Colorado w/over 300 days of sunshine but only really between May-Aug when the sun's high enough in the sky it can penetrate a forest canopy and let me bulk up my bank at higher charge rates than you.. After September the sun stops getting so high in the sky, the days get dramatically shorter with summer solstice in the rear view and winter solstice ahead.. that low sun means your only getting diffuse light if there's any trees nearby, by October you need a few acres of clearing to have any hope of direct sunlight, and then its only for a very short time.

 

[01tundra]

Understood, but what's you're average daily usage?

We can make it 7 days on 70-80Ah comfortably, we've done it several times now. With a 20% reserve we have 160Ah usable.

Our longest trips are 10 days, so assuming we use more than normal, say 15Ah per day, that would be 150Ah. No AC and if we need heat we use a Big Buddy heater a little in the evening and morning.

With our usage I'm not sure we even need solar, but I tend to overbuild everything I touch......

 

[dreadlocks]

My Fridge takes more than that.. 20-30AH a day is my bare minimum depending on temps, when the suns beating down I can up that to 85AH a day comfortably.. If I need fridge and heat its about 50-60AH day.

Ok couple questions then, how the hell is your power needs so low on a camper that big? No Furnace, no fans, lp fridge? and lastly, with such megar power needs, why'd you throw nearly $3k into your electrical system?

 

[01tundra]

Fridge on propane when dry camping (have dual 30 lb tanks on the tongue).

A few LED overhead lights, occasional water pump (have a accumulator tank to reduce cycling), no heat/AC, USB fan, charge phones/tablet a few hours at night.

I have the refrigerator door heater on a switch, can also turn off our ARP Fridge Defend system and internal fans individually, stereo standby is switched. I can switch the trailer to 0 amp draw if I choose to (yes including the LP/CO alarm, which I only turn off during transit).

Because I overbuild everything......which is painfully evident from build threads for my past rigs....and someday we may decide to travel out West and go camping with you . If I had a Prius I'd figure out a way to stuff a shaved 14-bolt w/ ARB under it.

 

[01tundra]

Just because I like being a prick, Lets assume you meant to say ”T-105 6V batteries in series. ”
Anyway, Sounds like at present, decent enough system.
Good to have Ah monitoring. If anything, its interesting data to follow.

You are correct sir, good catch.

 

[Martinjmpr]

Ok couple questions then, how the hell is your power needs so low on a camper that big?

Two words: Absorption Fridge.

Used to be you could buy a portable 3 way fridge that would run on those little 1lb propane cylinders. For whatever reason, they don't seem to be as popular these days as the more common 12v/120v compressor refrigerators.

Maybe because of fire hazards or maybe because people don't like the idea of an appliance running on propane inside the passenger compartment of a vehicle (both of which I think are very valid concerns, BTW.)

Still, I have to say that for us (we camp with a small trailer as well, ours is a 20' R-Pod 179 Hood River Edition) the 3 way fridge is a game changer in terms of having a fridge that is usable off-grid. When people ask "yes but how long can you run a fridge on propane" I laugh and say "we will run out of food to keep cold long before we run out of propane for the fridge."

 

[dreadlocks]

I boondock too much for that, I need something that can operate off level because getting a 20ft trailer level in the back country is easier said than done, I had a camper van with an absorption fridge and the thing faulted out all the time and left my food warm and didnt really get that cold when it was stupid hot inside the van..

He's carrying around ~110lbs of LP tanks and fuel on his tongue to only run his fridge, both his batteries and his solar setup dont come close to that weight.. I can only go about 10 days w/heat off my 30# LP tank.. my fridge can run indefinitely with my LFP power bank and solar..

 

[Martinjmpr]

I boondock too much for that, I need something that can operate off level because getting a 20ft trailer level in the back country is easier said than done, I had a camper van with an absorption fridge and the thing faulted out all the time and left my food warm and didnt really get that cold when it was stupid hot inside the van..

He's carrying around ~110lbs of LP tanks and fuel on his tongue to only run his fridge, both his batteries and his solar setup dont come close to that weight.. I can only go about 10 days w/heat off my 30# LP tank.. my fridge can run indefinitely with my LFP power bank and solar..

I think you would find that the current generation of LP fridges is much less finicky about level than the old ones. We've camped a lot in our Pod and although I strive to get it level, it's not always there. Still, never had an issue with our fridge and it stays icy cold (cold enough that I have to keep the controller on 3 bars out of 5, otherwise our soda and beer freezes solid and explodes in the fridge!)

We are on year 3 with the Pod and (fingers crossed) no major issues so far.

 

[dreadlocks]

yeah I cant say Ive had much experience with any made this century.. the old ones are complete rubbish so they musta came quite a ways if they are now trouble free.

Due to the design they still needa be fairly close to level, if your striving for level thats probably not much of an issue.. I try to level on one axis so nobody rolls outta bed, but the other axis sometimes is waaay off to accomplish this, and we just put our heads upslope.. its pretty frequent we're way outta 3% tolerance level the manual of absorptions call for.. It is pretty sweet his and your electrical needs are so low, I'd be very jealous if he was not carrying around 14 gallons of fuel for refrigeration.. there's always a catch.

Just pulled this outta user manual of a latest model Dometic 3 way off their website:

 

[01tundra]

Water heater is 120VAC/propane as well and furnace is propane, oven/stove is propane.

one tank is dedicated to our discada, since 99% of our cooling occurs outside.

Our Duramax doesn’t seem to worry about the weight of propane, but I did also reduce the tongue weight by 120# by switching to LiFePO4.

The fridge actually cools better on propane. Plus we have an Engel if we really want to get all fancy.

 

[dreadlocks]

Furnace needs electricity too.. and if its a standard Suburban furnace its gonna need a ton of electricity, but it sounds like you dont use that much.. I use mine even here in July because its under 40 degrees at night when your 10kft high.

Stovetops can go years off 60# of LP, especially interior stove tops as they are much less BTU than the outdoor ones that run off 1# bottles.. the oven I dunno, never had one of those fancy things before.. That is a nice thing about a bunch of LP tanks on the front is you never have to worry about being light on the tongue heh.. when I added one to my old cargo trailer it was fantastic, no longer rode like crap completely empty because it always had extra ballast on the front.. if your truck can handle it, nose heavy helps stability thats for sure.

Never got why those LP fridges work so well on gas and so poor on shore or battery power, I'd have to run mine off gas a few days before we went camping just to get it cold enough.. never seemed to get near as cold off shore power, and on battery it wanted to drain it in a few hours so never used that.

 

[01tundra]

Yeah there's now doubt we're heavy on propane, that's just how it came from the factory. I thought about going to two 20# tanks, but we're sitting right around 12-13% tongue weight so we're in a sweet spot now.

We rarely use the furnace all year here, if it's down in the teens we'll set it to 45F or so, but with two adults, a child and three dogs we stay pretty warm. The Buddy heater knocks the edge off pretty good as well. If we were fortunate enough to live in CO I would have to rethink my plan a little.

The heaviest user of propane on our trailer is this by far -

 

[01tundra]

Ours seems to cool down quicker on propane, but does fine on 120VAC as well. On AC in 95F temps it will pull down from ambient to 30F in about four hours if empty.

I've considered throwing the Engel in the truck bed as a back-up / outdoor beverage refrigerator.

 

[Martinjmpr]

Ours cools just fine on either 120vAC or propane. Battery is only used in-transit after the fridge is already cold. A couple of times when we were boondocking I forgot to change the fridge from propane to battery and drove home on propane with no issues. As I said, we have to keep our fridge setting on 3/5 bars or else the food in our main fridge freezes. Food in the freezer compartment is always frozen solid.

Ours is a Dometic 3 way. From what I've seen on the R-Pod Facebook groups, there are people who have issues with the Dometic fridge but we've been fortunate to not have any.

I LOL at the instruction that says "run the fridge on electric if you are over 5500'" We live in CO we are almost never below 7,000' when we camp and we've camped above 10,000' on several occasions with no issues.