Upgrading to lithium/solar on a class c motorhome

[Gondar]

TLDR: looking for a good all in one option for a class c to add 2x400watt panels to the roof. Any newer charger/inverter/solar controller that would allow me to use shore power and the Onan 4000 generator to charge the batteries when needed. Mostly would like to not worry about lights/tv/laptop always an option, and maybe the fridge or AC for short periods if needed? Not sure if the class c f450 alternator is worth connecting too? What size battery? Hoping to not spend more than ~$5000




Been poking around this forum, and some of the popular YouTube channels.

I'm picking up a 30' 2006 Bigfoot 30mhsl next week. I believe it is pretty standard with a 30amp plug, Onan 4000 generator, 12v/propane fridge, 13500 but AC roof unit.

I would like to upgrade it to lithium and solar, so that we could do some boondocking with it, and not rely so much on a gas generator.

The motorhome has a roof rack on the back that could easily fit 2 60"x30" ish panels. Maybe a 3rd, or another 2 towards the front, or portable panels to supplement them down the road. I'd like to get 300-400watt panels for 600-800watts of solar to start.

I have information overload at this point trying to decide between just getting something like the Ecoflow Delta Pro, and plugging in the 30amp shore cable to it, and charging that with a couple solar panels on the roof rack, or changing out the existing components with something like Victron, Renogy, or the Ecoflow power kit. Do I need to go as far as the power kit or a victron multiplus 1 or 2, or some sort of all in one system? Or are there cheaper options for just swapping out the batteries, disconnecting the alternator, and getting the solar setup. Should I definitely replace the inverter in an 06? Seems like the Ecoflow plus would mean a lot of changing plugs around if I needed to charge it from the generator, and it wouldn't charge from the front alternator. Is that really a big deal? Would I get all I need from the solar mostly? It would also mean I'd still have my original batteries, and potentially would need to disconnect or remove them so the Ecoflow wasn't just charging them, and having both sets of batteries for extra weight.

I would love some opinions about my options, and the pros and cons of each.

Ideally, I'd like to run the fridge, lights, laptop, and a tv off of the batteries. I also have 1 slide. In a perfect world, I'd be able to run the AC unit for an hour or two, or I'd be open to replacing the roof ac unit down the road with one of the newer low power or DC options that seem to be popping up, if that would make sense to achieve more ac run time for less money/batteries.

I do have a pull out slide storage compartment by the front, that houses the 2 current batteries. I'd be open to getting new batteries to go there, or finding room inside if it was needed for one of those eg4 setups with the rack battery. It is a 4 seasons fiberglass walls and roof class c.

12v, 48v (with the new AC options?), how many watt inverter? Why do most people seem to talk about 100-200 watt panels, when 300-400 watt ones seem pretty much just as cheap, and much better for the limited motorhome roof space.

So, any opinions on how I should approach this? I'm planning on taking it for a road trip not too long after I pick it up. My brother, and a good friend are both licensed electricians, so I have the help I may need, but neither are familiar with solar setups. I guess really what I'm wondering is what is the best bang for my buck for a class c design, that can be a bit set it and forget it, whether you need to plug into shore power, use the generator, and always be charging with the panels on the roof or alternator. If I can fit 2 residential 400watt panels on the roof, what makes the most sense for an all in one?

Thanks in advance for any help, and sorry about the long rambling post!

 

[sunshine_eggo]

The motorhome has a roof rack on the back that could easily fit 2 40"x20" ish panels. Maybe a 3rd, or another 2 towards the front, or portable panels to supplement them down the road. I'd like to get 300-400watt panels for 600-800watts of solar to start.

4 20"x40" panels is only going to be 400W, so you'll have to supplement with portables.

I have information overload at this point trying to decide between just getting something like the Ecoflow Delta Pro, and plugging in the 30amp shore cable to it, and charging that with a couple solar panels on the roof rack, or changing out the existing components with something like Victron, Renogy, or the Ecoflow power kit. Do I need to go as far as the power kit or a victron multiplus 1 or 2? Or are there cheaper options for just swapping out the batteries, disconnecting the alternator, and getting the solar setup. Should I definitely replace the inverter in an 06? Seems like the Ecoflow plus would mean a lot of changing plugs around if I needed to charge it from the generator, and it wouldn't charge from the front alternator. Is that really a big deal? Would I get all I need from the solar mostly? It would also mean I'd still have my original batteries, and potentially would need to disconnect or remove them so the Ecoflow wasn't just charging them, and having both sets of batteries for extra weight.

I can't comment on the use of "solar generator." I detest them.

Ideally, I'd like to run the fridge

Absolutely not. Keep this on propane. A typical 7.6cuft unit can easily burn 4-5kWh/day - that's over 400Ah of 12V capacity. I had a 10cuft unit that burned over 9kWh.

lights, laptop, and a tv off of the batteries. I also have 1 slide. In a perfect world,

Easy.

I'd be able to run the AC unit for an hour or two, or I'd be open to replacing the roof ac unit down the road with one of the newer low power or DC options that seem to be popping up, if that would make sense to achieve more ac run time for less money/batteries.

1-2 hours is pretty much a non-starter unless you're willing to really invest. IMHO, 1-2 hours of A/C use never happens. It's like getting a taste of something delicious and then realizing the bowl is empty. Better to not even run it at all rather than try to limit it to 1-2 hours.

While the higher efficiency units will help, it's still a tall order. A $1500 server rack battery can only run them for about 3 hours... assuming you don't need anything else running. 400W of PV would probably give you another hour, but after that, you're empty until sunrise the following day.

12v, 48v (with the new AC options?), how many watt inverter? Why do most people seem to talk about 100-200 watt panels, when 300-400 watt ones seem pretty much just as cheap, and much better for the limited motorhome roof space.

Beware - 20x40" panels are NEVER 300-400W. Easy to find thousands of fake claims on ebay, alibaba, etc., where they are claiming double actual or more. To sanity check a panel's rating, calculate it's area in square meters and multiply it by 200W.

20x40" panels are about 0.5 sq meters. That's a 100W panel.

So, any opinions on how I should approach this? I'm planning on taking it for a road trip not too long after I pick it up. My brother, and a good friend are both licensed electricians, so I have the help I may need, but neither are familiar with solar setups.

Start with link #1 in my signature. Find what solar is available at your location with PVWatts and complete the energy audit with your expected loads. With those two completed, the system basically designs itself. Once you have the big picture of what you need for your desired use. Then it's a matter of picking the equipment or drastically change your expectations.

 

[Gondar]

Thanks for the reply. I don't see a signature/link in your signature or in your profile.

I might have the size of the panels off. I have the space for larger ones. Just thought the qcell ones were close to that size, slightly under 400watts

 

[sunshine_eggo]

Turn your phone sideways and/or change your preferences:



A single 400W panel is going to be about 40" by 80" or 1m x 2m

 

[Gondar]

Turn your phone sideways and/or change your preferences:

View attachment 167598

A single 400W panel is going to be about 40" by 80" or 1m x 2m

Ah, I see now. I'll check it out.

I believe I have the room for that size x2 still on the rack, it's 8' wide

 

[Factsmanmp]

I have a 2005 30 ft class C too. I understand how overwhelming all this is. Btw, “sunshine_eggo” is a great source of knowledge.
I had a lot of the same questions as you listed. I’ve been researching, planning, saving and thinking about this project for almost a year. I’ve taken a few steps and I’m feeling pretty good about where I am and what is next. While our RV’s are very similar, there are so many options and “analysis paralysis” is to be expected. Like so many other projects, cost is usually an issue.
There are certain things that you shouldn’t skimp on…. Safety and expand ability. Wire size is one of those things. Components range in price so you have to research those. I’ve opted for middle of the price range with manufacturers that are proven and have a good track record. I too questioned an all in one system and thought I would go that direction but because of my situation decided on individual products. If you are interested in my project, let me know and I can share my steps towards installing the solar system in my RV.

 

[justinm001]

Start looking into a Victron inverter first and build out with their components to see what fits your need best then you can look for cheaper alternatives or features you don't NEED.

Going with a Victron MP you'd be able to wire it up so all power in flows through it which means you'd be able to take your 30a shore and it'll power assist the inverter so you have 50a instead of just 30... meaning you don't need to turn off the AC when using the microwave. then it'll recharge the batteries. This is well worth the couple hundred bucks more than other inverters.

load as much solar as you can. Panels are cheap and you only have so much room, you can't have too much. If cost is a concern then have more panels than you have charge controllers as you'd get more power and can also upgrade later.

go to currentconnected.com and price out everything you think you need. They're a great company, with great prices and only sell good equipment. Start there then you can work your way down the list.

skip the alternator for now as its only power sometimes. Its nice to add a DC to DC charger and get power while driving but not needed and a rabbit hole you can wait. Get the good system up first then work to improve it.

 

[RvNaut]

Thanks in advance for any help, and sorry about the long rambling post!

I converted my Class A to a lithium system... there is a fair amount to it, and you should dig into the systems in your coach. You can leave everything in the coach running as it is... IOW, the coach will not know anything is different, but there is "a lot to it", especially if you are not well versed in working with electricity. Understanding how it all happens now is critical, and then you can look at where and how to insert the new system an remove only that of the old that is obsolete.