24v and 48v RV Solar Systems Pros Cons Tips and Tricks

Thinking about 24 or 48v solar systems? We can help.
sotasolar.com

[@SuperSushidog]

When you're dealing with a big system, high voltage makes sense to me. I just finished a 48v system on my MH. It uses 8, 550 watt solar panels on the roof, wired in series, delivering 336 vmp (399 voc) to my 500v rated, 5,000w all-in-one inverter/charger/charge controller to charge a 16s 320ah (16.38kwh) prismatic cell battery. One BMS keeps them all in sync too. I have a 560ah 12v battery, to take care of my 12v needs and power a small 1000w inverter. It is charged by a 620w liftable array on the side of my coach (since my big array covers the entire roof.) Sure. there are challenges associated with using higher voltages, but their advantages, like smaller wiring, increased efficiency and simplicity more than offset their detractions on a larger system.

[@junkerzn7312]

Wow, you did a wonderful job on the commentary!. And it is refreshing to see someone talking about higher-voltage systems because too many channels push 12V gear well beyond the sizes where people should be going to 24V or 48V. I think mostly because a lot of channels get free 12V gear from vendors. One additional recommendation I would make is not only should the native batteries be at the system voltage, but there should always be at least two in parallel for redundancy and robustness. So 2 x 48V batteries in parallel, for example, for a 48V system. I am really happy with my 48V system. 24V wasn't enough once I started pushing 2000W worth of panels, but at 48V it is just crazy how cool everything runs and how small all the gear is. I am at the point now where I go straight to 48V even when I'm doing a small amount of solar. -- Victron is definitely behind the times on 48V gear. They have a 48V Multiplus II but it doesn't have split-phase output. And they don't have a 12V-to-48V DC-to-DC (they have all the other combos, though). There are plenty of other vendors that do 48V split-phase. The really popular one right now is the EG4 6000XP. Finally, an observation on inverter size. One disadvantage of big inverters is their idle power draw / overhead power draw. It can be 30-60W. But there is a solution! Hang a smaller inverter off the battery system that is always left on and use that inverter to run the fridge and all the low-power stuff (which is almost everything, to be honest). Then use the high-power inverter ONLY for the kitchen area, with a remote switch situated in the kitchen itself so it can be left turned off most of the time. The A/C system is debatable. Native DC mini-splits are pretty awesome once you've decided on 48V, but are an expensive upgrade if you wound up getting a 12V or 24V unit. So sometimes AC mini-splits or A/C units are a decent choice despite the lower efficiency. -Matt

[@sotasolar]

Thank for the great comment! Victron does seem to have more efficient inverters. They also have a mode where they will run as modified sinew I’ve or even search mode until a load is detected. It would accomplish that kitchen scenario without a switch at all. Great ideas all around, thanks for sharing!

[@SuperSushidog]

I like the way you think. One of the reasons I went with a 48v Sungold Power 5,000w all-in-one is it only draws 20-25w at idle in power saver mode. I also have a 12v 1,000w inverter wired separately I use when less power is needed (like for TV and computer use) using a smaller, 560ah 12v bank. It's good to have redundancy when living off-grid in our motorhome like we do. I was going to go with the hotspot 48v DC mini-split but chose the new EG-4 28.5 SEER2 plug-n-play mini instead.

[@ethanclement9647]

Thanks for reviewing pros and cons of 12, 24, 48 volt systems. Talking about having to balance individual 12 volt batteries is good to hear as it's not overly well documented elsewhere. Like you say, if you have a 24 or 48 volt system, you would ideally have matching battery voltages controlled by the built in BMS per battery. Some batteries do have a data bus that you connect between individual series connected batteries, but mostly that is not the case unfortunately.

[@OmahaWayne]

FANTASTIC Video with the exact question I was looking for an answer to. My 5th wheel already came with a 12 volt 2k inverter that hasthe built in transfer switch so I think I will stay with 12 volt until I get to the point of wanting to run an AC then switch over to 24 volt. Really happy with my 640 watts of panels and 50 amp victron hooked to my 280 AH diy battery. Thank you explaining in a way that makes sense to me.

[@ablejohnson]

This Sota makes since

[@dan32one44]

If you pushing less than 1500 watts 12 systems are fine more than that 24 volt .. my 12 volt has me running my heat in winter… it might not be for you and how deep your packets Good 👍 stuff

[@matthewknight5641]

I use two 2/0 hot wires and two 2/0 ground wires on my 4000 watt split phase low frequency sungold. Its considered to be way over kill but to minimize voltage sag during high amp draws its what i use for my 24 volt system. To make components last its what it takes. Sure it will run on less wire but its cheaper and safer just to double up the wire. Also use fus3s that are just under the rated wire amp max that way its safe but doesn't create a pinch point in the flow of power. I run a minisplit for heat and cooling and built my own 30 kw lifepo4 battery and have a backup leaf battery thats around 14 kw and use it with a victron DC to DC charger to connect the two batteries. I have 3200 watts of solar and three victron charge controllers. I love the victron gear but the inverter stuff they sell is super expensive and way to much involved with firmware updates and trying to get it set up. The sungold low frequency is way more power and has been super dependable. After loosing everything in the fridge 3 times because of the victron inverter i went a different direction lol. Anyways great video

[@andand4964]

Massive thank you ***** very informative, especially when comes to BMS controlled batteries connected in series. Top man !

[@lebraun12345]

Great video! I intend do install a 48v system in our horse trailer as the main use will be for extending an air conditioner. For the 12v system, I plan on keeping the old 12v system in place and just putting one of the 48/12 dc to dc chargers in. I’ve heard of keeping a battery in for those heave 12v loads like jacks, slide outs, etc.

[@sotasolar]

Yup, great way to go.

[@darrylm3627]

😄👍Good To Know, Great Tips

[@Sylvan_dB]

I prefer to start with limiting amps to a reasonable limit. Then figure how many watts are needed, and choose a system voltage to work with those constraints. I usually choose a design preference of 150 to 200 amps. At 12v that means a normal max of 1500 watts or an overall maximum of 2000 watts. Double that for 24v. Double again for 48v. The only problem comes in with larger systems (20kw to 100kw range) which is pushing the limits of 48v systems.

[@leelopreste8852]

Why can you charge your system through your battery's if the usage is less then the charge? Why all the smoke cover?

[@1GREATDANE]

Recommended Battery Balancer for 12 Volt Lithium Iron Phosphate Batteries in 24 Volt Packs ? CHINS 280AH with Low Temp

[@Mikesroadtrip-ec5kp]

I have a truck camper. Right now I have a 12v system. I want to change over to 48v system. But I want to change my A/C to a 12volt A/C. How could I run a 12volt A/C on 48v system? Or do you have a different idea?

[@sotasolar]

I think you’re looking for trouble and adding too much complexity . You’ll never get enough solar to realize the savings and efficiency of 48v . Stick with 12 in your case. The big efficiency gains for 48v is solar and inverter, you’ll use less of both with your setup. Biggest solar controller you might use is a 150/70

[@lee8652]

The problem I have with my 48v system (actually 63v) is there's no good way to charge the house bank with the alternators.

[@sotasolar]

It’s definitely a challenge. If you really need extra power there are 48v alternators. Another clever way is to use the alternator you have and a cheaper inverter and run a 120 vac 48v dc charger from that. JD’s bus runs a 48v system and he has so much solar they don’t even bother with alternator charging.

[@bscottyoung]

My installer suggested that going to 24 volts would require two 12 volt batteries in parallel as opposed to maxing out a 24 volt battery. Does anyone have an opinion about this?

[@sotasolar]

Yeah I do. I’m usually “many ways to accomplish the same goal” but on this I have strong opinions. If you stack 2x 12v 100a batteries with 100a BMS for 24v you don’t have a 200a BMS, you still have a 100a BMS essentially. It’s no different than a single 24v battery with a 100a BMS. The only difference is you have to now balance the two 12v batteries using an external balancer. I do agree you should not max out any BMS or battery. Run 2-3 batteries if you intend to max out an inverter. Just my $.02.

[@spitfire155k2]

Question, if you step up to a 24V or 48V system & alternator, how does that power the rest of the vehicles 12Vequipment? Really leaning in to a 24V or 48V system as the efficiencies are too good to overlook.

[@sotasolar]

Usually the higher voltage alternator is a secondary, or you use a high quality step down converter if just house loads. If engine start is still 12v, you need two alternators without some crazy tomfoolery.

[@spitfire155k2]

@@sotasolar great info thanks for the reply I appreciate it and love the content! Planning on full timing in a super C here in the next year and want to be able to boondock as much as possible.

[@sotasolar]

@spitfire155k2 if you’re thinking about Victron equipment 24 V is probably the right way to go when you’re ready to purchase I’d love to help you out

[@spitfire155k2]

@@sotasolar Fantastic! Will definitely stay tuned to your channel and give you a holler when I’m ready for some assistance! Thanks again and awesome content!

[@roybertalotto6355]

who makes 48v AC units?

[@NoelBarlau]

We're talking DC voltages here, just to be clear, (I know there are two conventions for AC - Alternating Current and Air Conditioning) but RecPro has some 48vdc air conditioning offerings, and others are going to be hitting the market in short order. The manufacturers know the benefits of 48vdc, and they're beginning to transition to it in the same way that 800v architecture is displacing 400v in EVs. It's a 48vdc future in RV land, and we're just seeing the beginnings of that transition today.

[@adamsisernik4556]

We have a mini solar system with a Basen Green 11,7kW 48V 230ah battery, which is charged via a Victron 150/35 by four Bluesun 480W panels on the south balcony fence with a total power of 1920W, which on a sunny April day charges this 12kW battery to 100%. With this system, we charge a 3.6kW Ecoflow Delta Pro battery - an inverter from which we use electricity for washing machines, drying, cooking, charging batteries, etc. We would like to upgrade the system with a three-phase inverter, which would supply electricity to the house on all three phases, namely in such a way that the first source would use energy from the panels, then from the battery and finally from the electrical network. Please, if you can advise us on a suitable inverter in the direction of establishing an optimal system.

[@sotasolar]

With 3 Victron inverters you can create 3 phase. Might be worth looking into .

[@adamsisernik4556]

@@sotasolar So I can start with one phase first to detect, how system works.... :) so which Victron to buy for one fase?

[@sotasolar]

Depends on your loads for sizing. At least the 3000va, possibly the 5000. Then it also depends on on your power standard. Are you US 120v or EU 230v ?

[@adamsisernik4556]

@@sotasolar EU 230V ... can you send me link to the 3000va or 5000va Victron, thanx

[@sotasolar]

@adamsisernik4556 www.victronenergy.com/inverters-chargers/multiplus-ii

[@superblondeDotOrg]

That beetle walking across the table though. Bug Power.

[@brianrhodebeck6465]

My 24 V. global aims inverter six thousand running 4 years Running a 2800 square foot home with no hiccup. I am happy Knock on wood.😅

[@sotasolar]

Great to hear!

[@jab376]

Thats good to hear. But doesn't that boil down to loads you put on your system after all these years?