Spent $5k and plans have changed, need to pivot and need advice what to do next with RV build.

I’m new to the forum, so I’m posting this here with the newbies… if it’s better suited for the mobile forum, please feel free to move it

So… a few weeks ago we passed through Sulphur Springs, TX on our way to Dallas for the eclipse. I visited Signature Solar and took delivery of 3 LL 48v 100AH batteries, an EG4 3k AIO, a 48v-12v step down transformer and a couple of bus bars. I chose these components mainly because of the limited space we have to work with and the desire to have enough capacity to run an RV air conditioner off-grid for extended periods over a long weekend. Grid charging was deemed sufficient for phase one as we typically spend a few days connected to shore power before venturing off-grid. Our RV is a 28ft travel trailer wired for 50A service from a NEMA 14-50R. I did not think through how to power the camper through the various ‘dog bone’ adapters we employ now and then when a NEMA 14-50R receptacle isn’t available. But that’s only part of the complication…

Since then, my wife and I have decided that we need a larger RV and are in the market for a 5th wheel (and a bigger truck to tow it!)

I’m still sold on installing a 48v DC system, there are just too many advantages not to, especially in a larger rig. I don’t think the EG4-3K is going to work for a larger rig, and with more space to work with I would rather install something that supports split phase AC out. I’m considering the EG4 6000XP, but would appreciate recommendations for alternatives. Roof mounted solar is likely to be a fast follow project since we’ll be heading into southern Utah soon and there will be a lot more sun and fewer 50A electric hookups to charge from.

kobalt60 said:

I would rather install something that supports split phase AC out

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Split phase power is unusual in an RV. There is both phases of the power fed in, but the bus bars for the power are separated so the ganged split phase circuit breakers won’t fit.

Usually it’s 2 x 120 volt ACs. Each AC takes around 1500 watts from the inverter and 1700 watts from the battery.

Your batteries are a decent size, and the AIO you have can power a single unit for hours.

I have a 24 volt system about the same size you mention. I need to fill my roof with panels and put about as many on the ground to run a single AC. Two ACs is not feasible. Also above 85 outside temp, the AC runs nonstop.

To piggy back on @chrisski, since there is no 240v need, you could just purchase another EG4 3000w inverter and wire each one up to half of your power distribution box (breaker panel). This will also allow you to plug into 50a or 30a RV service and it will either allow both or 1 inverter to charge with no hassle.

A 6000XP or similar split phase 48v inverter will not like being fed 120v, so its 50a RV service or nothing.

Thanks @chrisski and @Lt.Dan! it’s been a few weeks and I’ve decided to pivot to a Victron system with 2x Multiplus 48v-70A units.

The more I think about it, and to @Lt.Dan ’s point about the 6000XP, these AIOs are designed for residential systems with fixed utility inputs with parameters that fluctuate within a known band, but are very unlikely to change from 50A split phase 240v one day to 120v 30A or 15A service the next, along with all the crazy voltage fluctuations we see at RV parks in the summer. They also don’t work well with small portable generators and who knows how well they’ll handle the vibrations of travel days.

I think a system with components designed for mobile applications is probably going to be my best bet for reliable, portable power. Sure it’s more expensive, but it’s also amazing what a few weeks in the brutal sun of AZ will do to educate a person. Now to figure out how to mount enough solar panels to my 5th wheel to make two 5kVA units worth the money.

I do want to see pics of the build.

kobalt60 said:

Now to figure out how to mount enough solar panels to my 5th wheel to make two 5kVA units worth the money.

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If you look at my build part 2 in my signature block, I show what I did. Basically, what Will said about filling up the roof and putting just as much on the ground to run a single AC.

I did the build you are talking about … for most of the time they are correct you only need the 3000 watts across both sides of the split phase break, I used the 6000xp and replace all the a/c with split units also … and can run everything off grid with a/c’s 24x7 if Sunny.. 3700watts of solar on roof..

You can see setup below and got picture if you need them and a few items you will need to deal with electrical wise if your still working through it …