Maximizing Solar and Inverter Setup for High-Power RV Needs

[FiveOclcok]

Just picked up a 2026 grad design Imagine 2920. It came with a 200 watt solar panel on the roof and inverter ready. So I started looking at pannels and have no clue how I am going to this. It seems like I can only get maybe 10 - 200 watt panels up there. Attached is a layout of the top of the RV. I looked into higher wattage panels, but I dont see how I can fit a single one on the roof. So the question is will 2000 watts be enough? We have 2 100 AH lithium Batteries on one bank and a 280 AH lithium battery on the other bank. I was thinking of maybe running the 2- 100AH just for the house battery and leave the orginal solar alone. then start from scratch with the left over 9 panels, then install a 3000 converter. I am just trying to find a way to get more than 3000 watts to the breaker pannel. On our last winnebago we had a regency 3000 and it would not even run the microwave for 3 seconds. But that one was not setup correctly, it did not have inverter prep. I litery just thew it in a cabinet and removed the onboard converter and ran wires to the pannel. The inverter was at least 20 feet from the batteries using orginal wires. So I dont know if that was the reason or just a cheap inverter. MY main point is how do I get the most wattage for space I have?

 

[Gary RV_Wizard]

So the question is will 2000 watts be enough?

The question is "Enough...for what?" The very first thing you must do is figure out how many watt-hours you will consume on an average day. That's the amount you need to replenish (put back into the batteries) on an average sunny day.
Your existing 200W panel is "enough" if you aren't using much power, but even 2000W isn't enough if you are trying to run an a/c off the batteries.

Forget about that previous rig. I don't know what a "Regency 3000" is, but something about it was clearly very wrong if the microwave couldn't run. It's no longer relevant, so forget it.

 

[FiveOclcok]

According to the website I just went to I put in the TV running 24 hours, 2 hours of coffee-making, 2 hours of microwaving, 24 hours of Wi-Fi routers and cell phone charging, so I know that all seems high but the number was amazingly low? According to the website I only need about 1300 amp hour per day.( see attached picture). But also because of the sun only being up 6 hours a day it says I'm in the negative. I also this assumes I am running 12 volt solar panels, I was going to run 24V, because I've heard they were so much better.
I think I understand what all this means, but what I still don't understand is how to fix it, if in fact I am in the negative.

 

[Gary RV_Wizard]

I don't consider 1300 amp-hours per day to be "low" at all. That's 15,600 watt-hours! And you didn't even include lighting or other appliances.

Two hours of actual microwave runtime is huge. That's like baking two big casseroles or pot roasts every day! And you can turn off the tv when you go to bed, right?

 

[IBTripping]

If it was me, I'd get a bigger battery bank than the 200 ah you have now. You could consider replacing your current batteries with a single 600 ah system. If a large 600 ah battery won't fit, you could replace your two 100 ah batteries with two 314 ah mini batteries. I'd also carry a small (2,500 watt) generator for when the sun doesn't shine. Just my opinion, but I'm doing similar with my rig. Good luck and safe travels.

 

[John From Detroit]

One comment on what IBT said
Batteries not AH but WH = LB By that I mean a 200 ah 6 volt battery weights about 1/2 what a 200 AH 12 volt battery weighs

So 200 ah of battery (a pair of GC-2s?) is 1/3 the weight of 600 Ah of the same type of battery.


NOTE: Flooded wet, Sealed (maintenance free) or AGM makes a little difference. but only a little.

Switching to a totally different chemistry Like LiFePO4 can make a difference

600 AH at 12 volt... Fork lift suggested for install

600 ah of LiFePo4 by multiple batteries in parallel. Well That you can do

I've got 3 100's behind me here (LiFePO4) for back up power
(More scattered about the apartment in EPS and UPS boxes.

I

 

[Primerump]

Just picked up a 2026 grad design Imagine 2920. It came with a 200 watt solar panel on the roof and inverter ready. So I started looking at pannels and have no clue how I am going to this. It seems like I can only get maybe 10 - 200 watt panels up there. Attached is a layout of the top of the RV. I looked into higher wattage panels, but I dont see how I can fit a single one on the roof. So the question is will 2000 watts be enough? We have 2 100 AH lithium Batteries on one bank and a 280 AH lithium battery on the other bank. I was thinking of maybe running the 2- 100AH just for the house battery and leave the orginal solar alone. then start from scratch with the left over 9 panels, then install a 3000 converter. I am just trying to find a way to get more than 3000 watts to the breaker pannel. On our last winnebago we had a regency 3000 and it would not even run the microwave for 3 seconds. But that one was not setup correctly, it did not have inverter prep. I litery just thew it in a cabinet and removed the onboard converter and ran wires to the pannel. The inverter was at least 20 feet from the batteries using orginal wires. So I dont know if that was the reason or just a cheap inverter. MY main point is how do I get the most wattage for space I have?

wowa.. tap the brakes there guy.. don't be in a hurry to put "xx" amount of panels anywere until you have a better idea of what you are trying to achieve.

just FYI, i'm a retired professional and have many years experience with solar. My suggestions will be a little different to what you may have seen on diy forums, however the net result should be more in line with your requirements. also, you are going to get sticker shock for some items, especially batteries.

First things first.. what are you trying to achieve ? is this a boondocking rig, a fulltime home or just a weekend warrior setup ?

secondly and the most important is the daily wattage use. In order to achieve something that will meet your expectations, you have to know how much power you expect to use in a day and for how many days before you go dark..
let's take a look at your initial use, which BTW is excessive, in my opinion.
you state
1) TV running 24 hours,
2) 2 hours of coffee-making
3) 2 hours of microwaving
4) 24 hours of Wi-Fi routers and cell phone charging

that's a lot of energy dude..

Here is a rough estimate of your energy requirements.
TV typically 50W, Coffeee machine 900W, Microwave 1300W, Wifi and Phone 5W and 18W
just estimates, but will get you in the ballpark..

Total: 50*24 + 2*900 + 2*1300 + 5*24 + 18*4 = 5792 w/hr not including lights and any other loads.
so 5792 Watt hours approx. equates to 500Ah @ 12V or 250Ah@24V as an absolute minimum capacity, with lithium you would need 600Ahr realistically to supply that load.

Just a ballpark figure.. to recharge that bank in one day assuming full sun, you might need in excess of 1500 Watts of PV to break even, IF you have 6hrs of good sun. In practice, you will most likely need > 2500W of PV to achive that goal. Now, that's only for one day.. what if the sun doesn't shine for 3 days ?
then you will need 3*500Ah = 1500Ah to maintain that usage.. do you see an issue here ?
I hope you have a generator..

From a practical standpoint, I would suggest reveiwing your usage and perhaps cook with propane, watch less TV and consume less power, your solar requirements will drop dramatically if you do..

please feel free to ask questions..

 

[Gary RV_Wizard]

Batteries not AH but WH = LB By that I mean a 200 ah 6 volt battery weights about 1/2 what a 200 AH 12 volt battery weighs

Not relevant, John. The chemistry of a lead acid battery requires a certain amount of lead for a given amount of 12v amp-hours (watt-hours). Since you need 2x as many 6v batteries to get the required voltage, the weight per watt hour works out to be identical.

 

[John From Detroit]

Not relevant, John. The chemistry of a lead acid battery requires a certain amount of lead for a given amount of 12v amp-hours (watt-hours). Since you need 2x as many 6v batteries to get the required voltage, the weight per watt hour works out to be identical.

That is exactly what I said.. Watt Hours = Pounds

So if you get a single whole lot of watt hours battery (And yes I've done that for a special event, not RV related) you need a fork lift to "install" it (Which is exactly how they "installed" it on the trailer it stayed on during use).

Oh the same battery (well a twin) powered the fork lift.

 

[Mark_K5LXP]

I am just trying to find a way to get more than 3000 watts to the breaker pannel.

You want more power from solar/batteries than I draw in my class A connected to shore power with A/C running. No question it's possible, but expect the system to be large, and expensive. When you apply real world device draw and duty cycles to your system I think you'll find the implrmentation will be more manageable and affordable.

Mark B.
Albuquerque, NM

 

[John From Detroit]

I am just trying to find a way to get more than 3000 watts to the breaker pannel.

Watts to the panel is determined by the inverter or inverters (Some inverters you can pair two 120 inverters to get 120/240 volts, but you need to know how to use those. (You don't need that in an RV anyway)

Watts times hours you need bigger batteries. or more batteries in parallel.

A single pair of GC 2 (220 amp hours total about 50 usable for a truly big inverter under heavy load) you can get 3500 watts if you want. but only for... Well less time than I spent typing this.

 

[Primerump]

"I am just trying to find a way to get more than 3000 watts to the breaker pannel"

that's the easy part, just size the inverter and battery bank accordingly.

"On our last winnebago we had a regency 3000 and it would not even run the microwave for 3 seconds. But that one was not setup correctly"

clearly, I run my a/c overnight on a 3000VA inverter without issue.

"MY main point is how do I get the most wattage for space I have?"

as you have discovered, RV's are not PV friendly, too many roof "obstacles". one solution is
to populate the roof with many smaller panels, others have larger panels on a raised frame.
My own solution is to use stacked panels on sliders much like a draw that extends out. there are many ways to achive your goal, the correct thing to do however is to re-evaluate your usage patterns, minimise power consumption by changing habits slightly to conserve energy. cook with propane not electricity, you state "TV on for 24hours".. what kind of camping are you doing ?

 

[John From Detroit]

I would love to see Solar Awnings. Basically, it's flexible panel strips (strips like venetian blinds) on top of the canvas of the awning and some special stuff so that they work well. That's a lot of solar "Real estate". I do know it can be done, using thousands of cells, but I'm not sure how practical it would be at this time.

 

[Primerump]

I would love to see Solar Awnings. Basically, it's flexible panel strips (strips like venetian blinds) on top of the canvas of the awning and some special stuff so that they work well. That's a lot of solar "Real estate". I do know it can be done, using thousands of cells, but I'm not sure how practical it would be at this time.

a good idea and use of available space, however, current technologies are too ridgid and suffer from breakage. also they are much less efficient and have a much shorter lifespan.
oh yeh, they are also much more expensive per Watt.. so wait another 10 years or so and it might happen.

 

[FiveOclcok]

WOW thanks for all the info. I have made a few adjustments, well just one! I am moving to one 48V 100AH LiFePo4 and I have room for one more if needed. I also have the 50 amp ATS on the way as well. I am looking at the victron 48V 5000 240V MultiPlus-II. This is a 50-amp RV with inverter prep, but the inverter prep wiring is only 10-gauge. I have one inverter-prep breaker on each leg of the main breaker panel.
My understanding is that the Victron 240-volt, 5kW MultiPlus-II provides split-phase output to the panel, feeding each leg of the breaker panel. I also assume the total output is 5kW, split between the two legs rather than 5kW per leg.

Is this split-phase output the primary difference between the 240-volt and 120-volt MultiPlus-II models?

Since I do not currently have any 240-volt loads in the RV, I am trying to understand whether there is a real advantage to using the 240-volt unit versus the 120-volt version. Are there any additional benefits or drawbacks I should consider when choosing between the two?

I also have some confusion regarding the transfer switch, since my generator is only 120 volts.

On the generator side of the automatic transfer switch, do I bond L1 and L2 together, since the generator only provides a single hot conductor, neutral, and ground? In contrast, the shore power feed has two hot conductors, a neutral, and a ground, and the wiring going from the transfer switch to the inverter and main breaker panel is also two hots, a neutral, and a ground.

. . and yes I am working on solar pannels on a slide, so I can slide out over the bump outs, and I did find 450 watt pannels so that should help.

Thank you for your guidance—I appreciate any clarification you can provide.

 

[Primerump]

WOW thanks for all the info. I have made a few adjustments, well just one! I am moving to one 48V 100AH LiFePo4 and I have room for one more if needed. I also have the 50 amp ATS on the way as well. I am looking at the victron 48V 5000 240V MultiPlus-II. This is a 50-amp RV with inverter prep, but the inverter prep wiring is only 10-gauge. I have one inverter-prep breaker on each leg of the main breaker panel.
My understanding is that the Victron 240-volt, 5kW MultiPlus-II provides split-phase output to the panel, feeding each leg of the breaker panel. I also assume the total output is 5kW, split between the two legs rather than 5kW per leg.

victron units only provide single phase. either 120V or 240V for ROW. ( rest of world )
therefore L-N and Ground

Is this split-phase output the primary difference between the 240-volt and 120-volt MultiPlus-II models?

they are 120V or 240V single phase.

split phase is the US embarrasment sadly. ROW typically uses 230/240 single phase, it's much easier to provide power as the current is halved vs 120V.

Since I do not currently have any 240-volt loads in the RV, I am trying to understand whether there is a real advantage to using the 240-volt unit versus the 120-volt version. Are there any additional benefits or drawbacks I should consider when choosing between the two?

very few RV's have 240V appliances, those that do are most likely high end units of $1M and up.
what you really have to decide is will you ever install a 240V appliance ?
there are several solutions i'll get to.

I'm short on time right now, I'll post something extra tomorrow..

 

[Primerump]

Considering the fact that you don't actually need true 240 split phase, my suggestion for you is to use
one or two multiplus 2x120 units ( two in parallel if you need the extra wattage )

My reasoning is:

1. The multiplus 2x120 units have in built transfer switches and will accept 120 or 240 from
either L1-N-L2 or L1+L2-N from a 30a source.
you get the best of both worlds, both 240 and 120 are routed correctly. for the 240 supply, the victron switches the inputs to the outputs 1 to 1 and you get full pedestal power available. for the 30A single phase via a 30 to 50 plug adapter, you get 120 on each phase ( in phase, not 180 apart ) and the full output of the inverter(s) on both phases.
2. as the inverters are 120V capable, you can run a generator direct in on the 30 to 50A combiner plug as well.

 

[FiveOclcok]

The problem is they dont make a 48volt MP 2 x120

 

[Primerump]

The problem is they dont make a 48volt MP 2 x120

it's not really a problem, it's about wattage.

3000VA is is just fine for a 30A RV and is comfortably met with 24V
there is no real reason to use 48V.
wiring for 3000VA at 24V is quite manageble, 2AWG would suffice.

for 50A just use two units in parallel and know that you have a backup if one unit should fail.

if you have already purchased a 48V battery then return it. sorry if you put the cart before the horse.. it's called research and design. know what you need before you spend.

 

[FiveOclcok]

I’ve considered redundancy, but isn’t that essentially the only real advantage?

Correct me if I’m wrong, but with two 48-volt batteries I would have approximately 9,600 watt-hours while only adding about 150 pounds and taking up very little space. To achieve the same watt-hours at 24 volts, everything would effectively double—size, weight, and battery count—unless I were to spend significantly more on a couple of 230 Ah batteries.