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

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

[junkerzn]

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

[michelmoss]

1590W Solar through 500V dual pole cutoff switch into Victron 150/60 charge controller Quattro 24/5000 with 2 24V 200 WH batteries servicing a complete RV rewire after gutting, new framing, subfloors, insulation, walls ceilings, macerator toilet, 36x6 foot walk-in shower and entertainment center. All for less than half the cost of a small piece of showroom junk from the dealership

[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.

[ethanclement]

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.

[matthewknight]

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

[Customers_support]

This is awesome. I was thinking of a 12v set up but size, weight bang for the buck a 24v sounds better.

[bgzwlz]

Honestly, a lot of this went over my head, however I think that based on what you said, anyone wanting to run an AC for more that 30-60 minutes should consider stepping up to a 48V system. Wouldn’t this be anyone who would possibly want to explore the SW in their van during most of the year? I understand that the biggest impediment to going with a 48V system would be inability to charge with a factory installed alternator, but the alternator could be replaced or a secondary alternator could be installed? Do you have a video describing the details for this? Finally, I think that the other big problem is running most of the electrical devices that aren’t compatible with 48V so you can buy some Orion device that solves that problem? Also, for some reason which I don’t understand if you have 400ah of batteries with a 12V system you only need 1/4 or 100ah with a 48V system? Now I plan to watch your other videos to help figure all this stuff out.

[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.

[andand]

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

[danone]

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

[lebraun]

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.

[BrianSmith-ynzg]

I think 52v is the next step and it might be coming sooner than some think. A lot of E-bikes are 52v already so it is coming. Yes I know E-bikes are a totally different thing but hey it all starts someplace.

[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.

[leelopreste]

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

[GREATDANE]

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

[lee]

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

[andand]

Thinking to step up from 24v to 48v, installation have two of Victron 12v to 24v dc to dc chargers. What do you think about connecting them in series to end up with 48v of charging voltage ?

[spitfirek]

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.

[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?

[brianrhodebeck]

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.😅