Good info that I may refer back to. Just an RV newbie. Had a 2021 Class C and now a 2025 Airstream Classic 30.

The AS seems to be designed for those that spend every night at a full-service campground... Bad on the salesman that told us we could boondock for 3-4 days with the factory 300w Solar and 200Ah LiFEPO4 batteries. Bad on me for not searching that out further. With a 12v compressor only fridge, you are lucky to make it 2 days with nothing but the fridge, unless MAYBE you are in full sun at a low lattitude.

We are sending our AS out to do a raft of upgrades:
Replace 200Ah with 800Ah batteries
Replace 300w solar with 800w
Replace charger/inverter with Victron 3000w Mulitplus
Add transfer switch (the AS does not HAVE a transfer switch. Everything is either 120v or 12v. And the only 120v that will run off the inverter is ONE outlet) so that we can run any 120v off the inverter.
Buncha other stuff that supports the above.

 

Holy cow,,, sounds like a awesome round of upgrades right there, especially for a towable.

I've managed to stay out six days with 400ah of LiFePo4 and 600 watts of solar, but the batteries were at like 12% when I finally left. I had two small propane powered generators with me (never used them, but nice to have them just incase the solar couldn't keep up). But I did have nice weather the whole time which made good use of the solar, pretty sure if it had been cloudy or rained I wouldn't have made it all six days without running a generator.

If you're gonna boondock, solar and LiFePo4 are great, but IMHO, its always nice to have some fossil fuel backup. I keep a couple of these little guys, technically they're dual fuel (gasoline or propane) generators in my camper. I don't carry any gasoline with me (tow vehicle is a diesel), so I made a hose that connects to my outdoor kitchen's propane quick connect and feds the generators off the camper's normal tongue mounted propane tanks. With both generators in parallel I can run both roof AC's (they have soft starts on them) if we're in need of some AC (which when camping in Texas, sometimes you just need some air-conditioning).



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With only Shore Power as a 120vAC source, I would argue that there's no need for a transfer switch at all. I would run the Shore Power directly to the Multiplus and then connect the Multiplus to the trailer's Main Distribution Panel.

Yes, you need to turn on the inverter to have AC power in the trailer. It doesn't pass through AC unless it's on. My inverter stays on all the time, but I use the inverted power to keep the batteries in my ATV charged.

 

I think you must misunderstand - I don't want to rely on shore power!

And, the way the AS is set up from the factory, there is ONLY ONE 120v outlet that works off the inverter. So, we have lights, fridge, water pump, heat. For sure, "livable", but not ideal. No A/C, only the one 12ov outlet (which is in the "media cabinet" above the dinette), no oven/microwave (range TOP is propane). Simply untenable.

 

Yes, I do have a 2kw gas generator that can be used if/when necessary, but I hate the noise - even though it's an inverter model that is "relatively" quiet.

Cool idea. I may go to a dual fuel.

Yes, adding soft starts is also part of the upgrade. We should be able to run one or the other A/Cs off the inverter.

Also adding a 100A DC-DC charging system (dual 50A) so we can ensure a full charge when we arrive at a site, and as a backup if we need to while parked.

 

He didn't misunderstand - you don't need a transfer switch with the Multiplus. You are going to wire the shore power input into the Multiplus. You wire the Multiplus output to where the shore power was connected to the RV. Now, when you turn the Multiplus on, it will pass through shore power - or generator power if you are running on that. If there is no incoming power, the Multiplus will power the entire rig via the batteries. That is exactly how my previous travel trailer was configured. I had way more battery and two Multiplus inverters wired in split phase, with 1,140 watts of solar on the roof. It worked awesome for boondocking. My biggest issue was the dang grey tank was too small (or my wife uses too much water).

 

As is with almost every life scenario, there are few absolutes. In your use case, an ATS may be un-needed. When your batteries run down, your RV shuts down. That works for you, but some of us have dogs that need the A/C to continue to work when we hit the trails, go to town, etc. An ATS allows that to happen without us having to be there.

Like most things man-made, I'm sure there are varying levels of quality available when buying an ATS. A quality ATS, properly wired and configured, will not constantly switch back and forth when "power flickers". Mine is tied into the inverter and doesn't try to switch the generator on until the batteries are becoming too discharged. Like anything, an ATS is man-made, so it certainly can fail. I personally have not experienced that or witnessed it with all of my RV / camping / off-roading friends, but I'm sure it happens. Finally, the ATS on the generator feed on the house has not failed in over ten years of use.

 

You're right - I was misreading the scope of work, probably because the first place* I talked to about this said I needed a transfer switch. Here's what it says:
Ain't gonna touch that one!

*Based on the follow up, or lack thereof, even when pursued by me, I think they were more backyard mechanics rather than real professionals. The only good thing about them is that they were only a 1 hour drive away, as opposed to the place I've selected, which is 10 hours...

 

This is how my camper is set up right now. 30 amp service, wire run through an EMS, and then straight to a single Victron Multiplus. From there it goes to the AC/DC box, which of course controls everything in my camper. So, even if unplugged and just running off of batteries (I only have 315 A of LiFeP04) everything in my camper is powered. I have 600 watts of solar on the roof that do an ok job at keeping the batteries going, of course that depends on situations. I also have a Champion 3400 watt dual fuel generator that I keep with the camper (I actually need to crank it up...), which if I use it, I just plug the cord into it, so no transfer switch needed. I also have an Orion XS installed to help keep my batteries going while traveling. This set up works pretty well for me. Especially in the summer time, I have to be mindful of my power usage, but when not needing the AC all day long, it is a pretty good set up. I would love to have about 600 A of batteries and at least 1000 (prefer 1200) watts of solar... these are things I now realize and keep in mind for our next camper though (assuming there will be a next camper).

Also, I recently installed a Furrion 18k Chill Cube AC unit, and wow, that thing is great! No need for a soft start, and the power usage is way lower than the previous (smaller) 13.5K AC unit I had installed! Getting used to the way these things run was a learning curve, but I eventually pared it with a Cielo thermostat so now I can just set schedules and what not with it. I can even use my Alexa devices to control it, as well as have access to it even when not at home (our camper).

And yes the Victron stuff is amazing. I don't understand a lot of it, but it seems like everything I want to do there is a way for the Victron stuff to do it. We are full time in our camper at a campground with power, however, I like to work my batteries so I have the Multiplus set to Sustain which "prioritizes" my solar over shore. Basically, the Multiplus will allow AC power in to power the AC side, however, the DC side operates from the batteries only. Sustain mode will not use the AC input from shore to replenish the batteries, so the solar is in charge of keeping my batteries topped off. Something else I have done is limit the AC input down to 9 amps, so the shore power isn't always enough to fully power the entire AC side which means the Multiplus will then assist the shore power with the batteries. Especially at night when I have no solar coming in, my batteries SOC will drop as it is being used, then the next day the solar will replenish the batteries. As summer turns to winter, I simply adjust the input limit to make sure the batteries are still being worked, but also not draining the batteries fully.

 

The ATS on my Generac home standby generator did fail on me once, well kinda anyway, with less than five years of very rare use. It switched to generator power like it was suppose to when the power went out , but when line power came back on it wouldn't switch back for some reason. Had to manually turned off the generac, which killed power to the house of course, then it switched back to line power. Only did this once and worked fine for a few years after that until I moved and sold that house. I guess that's probably the least impactful way it could fail, but still a failure (or malfunction at the very least).

Didn't want to spend the money for another standby generator at the new house, so I just run my tractor and use a PTO generator to power the house when needed (living in south Texas the summer heat is no joke, so I wanted a means to run the house AC if power was out or they started doing planned rolling brownouts again). More setup time (not automatic obviously), but WAY cheaper than the Generac setup. If a few years I'll probably move again into a more forever home, when that time comes I'll spend the coin for another Generac.
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Wow, sounds like I have a lot to learn!

 

Speaking of which, I "installed" i.e. put in place, a 20Kw standby at our second home. (Natural) gas was installed at N/C, and I received a quote of $11,500 to hook up the gas and electric (I have the transfer switch). Is that in the realm of reality? I was shocked. It will be a pretty straight-forward install - the only thing is that there is a concrete sidewalk between the generator and the gas main/house/electric panel.

 

If you have ever run a business, you will understand that is a lot of overhead. I can only imagine how much liability insurance is. Medical Insurance for your employees. L&I insurance for the employees, etc. It's not cheap to run a business. What you think might take a few minutes/hours to hook up is not the issue. Someone has to pay to keep the doors open. People seem to forget, all expenses that a business runs into is passed down to the end user.

$11,500 does not seem to be extreme to me, but then I have a small business and understand what it takes to keep the doors open.

Not certain what the rules are, why don't you install the stuff. All it has to do is pass the codes [assuming that there is no requirement that a licensed person has to do the install]. The codes are written.

Maybe that should have been looked at before you put it in place.

 

I think if you take a close look at the quote there is a lot of added work cleaning up all that stuff mounted on the side of your house. This is coming from a retired self employed electrician.

Let's not let this thread get to far off charging lithium batteries.

Denny

 

I have owned the same business for 37 years. I pay over $250k* per year in insurance, $75k in electricity, another $100k in our part of FICA and 401(k) . I understand overhead.

I am comparing what it cost to set up the same generator at our main house. Including gas installation (which was free at this new house, paid at the last one), it was under $5k. Granted, it was 7 years ago, but I wouldn't think things had tripled/quadrupled since then.