12V vs 24V vs 48V (For Camper Electrical Systems)

This video will quickly explain the pros/cons of 12V, 24V, and 48V electrical systems for campers and give you some considerations on which to choose.

Here are some additional resources that you may find helpful with planning and installing your DIY Camper:

[mattmcfadden]

I swear every time I have a question I google it and one of your videos is there to answer it. I just want to say I appreciate your videos.

[junkerzn]

I don't usually comment on 1yr old videos but I'd like to say I think you did a pretty good job here, and the video has aged quite well. I'll throw in a few remarks on 48V.

One thing you didn't mention is that lowly Victron 100|20 charge controller can do 12, 24, or 48V. And at 48V and 20A that cheap itsy bitsy little charge controller can take 960W of solar all by itself. Just remembering that the minimum operating voltage from the solar panels has to be BAT+5V higher (so around 65V minimum which is typically 2 or 3 panels in series, depending on the panels). Throwing a few of those together ganged to the same battery bank is easy and gives you a bit of redundancy on the DC side pretty much for free.

DC miniature circuit breakers (DIN rail mount) are pretty cheap these days. I would say that when it comes to DC miniature breakers, consider "B" type instead of "C" type. Most will be "C" type which are great when there is a lot of inrush current, but the "B" types have tighter specs and are typically higher quality to boot. So if inrush current isn't an issue, the "B" types are the ones to go with.

For example, The Chtaixi DC miniature circuit breakers have worked well for me. Type "B", 125A at up to 110V for around $20. Of course, many amperages are available.

On DC to DC converters. The cheap no-name brands on Amazon actually do work pretty well and have basic short circuit protection, but should definitely still have a breaker or a fuse on them because they do not have over-current protection (even when they say they do, they actually don't). Beyond that, though, there isn't a whole lot that can go wrong below 10A so for running low-power stuff they're great. I have no qualms using them below 10A on the output.

More than 10A, though, is another story when it comes to DC-to-DC converters. Go with a well known brand above 10A.

For charging 48V from an alternator, consider using a "boost" style solar charge controller. Not the Victron's.. .the Victron's are all "buck" style (output voltage must be lower than the input voltage). So if you have a 12V alternator, go with a charge controller that can boost the voltage into the 48V range. That way you get a proper battery charging profile for free AND you have complete control over the charge current. i.e. get a charge controller where the maximum charge current can be set.

The great thing about this is that you have full control over the charge rate via the current setting on the charge controller, so it can be programmed to guarantee basically zero stress on the alternator even if it is charging for hours. Keeping in mind that the amperage on the 12V side will be 4x the amperage on the 48V side, of course.

Finally batteries. LiFePO4 is expensive but its freaking awesome. But I advise AGAINST putting lithium based batteries in series because even when they say they can do it, having BMS's that don't talk to each other can cause serious issues when charging if one battery decides to disconnect charging before the other battery is able to finish. Things can go out of balance pretty badly.

So lithium based batteries should universally be wired in parallel. My only other comment here is to always have at least two batteries in parallel for generous amperage margins and robustness against problems and BMS disconnects. At whatever the voltage one choses to go with.

For inverters... consider that multiple smaller inverters are an option (separate outputs, obviously not paralleled since most inverters can't do that). Inverters with lower wattage outputs also tend to have lower vampire current draw and this way heavy loads can have their own appropriately-sized breakres and won't interfere with nominal light loads.

[WillProwse]

Awesome video 😁👍🏻 the no name 48>12 buck converters are very reliable and actually have safety ratings. Designed for automotive use, they work well. Very efficient as well. To run 12V jacks, I would use a buck converter with an output voltage that was the float voltage of an AGM, then run the jack off the 12V AGM. Did this for a year and it worked great.

I did blow a buck converter to pieces when I was using it as a solar charge controller 😂 had a morning voltage spike and a capacitor blew. It was potted so it exploded to a million pieces haha

[evil]

Great vid Nate, this is a good explanation of differences between system voltages. You have a very clear & concise method of teaching. Andy’s Off Grid Garage Australia channel has a lot of info on 48v systems. I am currently playing with a 24v system in a bus, & a 48v system at home. In Australia we use 240vac of course. I watched ur whole 24v build, it was very clean and nice. Cheers

[dondartt]

Perfect explanation, right to the point. We’re using 12v with 3000 watts of inverter. This is the max according to your guidelines.

[JamesGoodin-USMC-]

Very nice explanation of 12v to 24v. Someday I plan on living out of a RV and your videos are giving me the ammo I need when the time comes to pull the trigger on my plans. Thanks for your helpful videos. They are very well laid out and that little blooper you left in was fun.

[VerissimusAurelius]

Rarely have I seen a complicated system explained so eloquently👀👍Thank you!

[HeidiandFranny]

Thank you for explaning this and your video summarizing at the end is perfect. Hopefully, you have 100 percent engagement through to the end!

[hermangareis]

Great video Nate!! You just confirmed that I made the right decision to go with 24v. My decision was based on the AC unit and fridge as well as other components that were all 24v. For the small stuff in the RV such as lights I just use a Victron step down converter to 12v. My battery bank is a 24v 15.6KwH unit and 3000 watts of solar.

[Amidez]

Absolotely perfect video that I can recommend to anyone going to build your own FVE.
Lenght, used terms and explanation at highest level considering it is made for beginners.

It helped me finaly decide.

Thank you.

[mubaraksadik]

Watching from Nigeria really appreciate your efforts, thanks man

[michaelbacks]

Nate, outstanding video, long time subscriber. I built a 24V system using a 3000W AIMS and 1030W on the roof of a 5th Wheel back in 2016 for many of the same reasons you mentioned, and I used two different 'no name' 24VDC/12VDC converters because I ended up burning the 60W version out powering the Hydraulic slide motor and had to get a 80W version. But the small one worked ok for the rest of the 12V equipment. Real world results.

When I 'upgraded' to a newer 5th Wheel in 2018 and went with a 12V all Victron setup with lithium batteries, I have noticed a significant decrease in available power, I maintained 4/0 wire between the batteries and inverter within 2 feet of each other to minimize resistance. But I can not run the AC for as long as I used to on the 24V system and the batteries were four 115A of AGM in 24V (2s2p) upgraded to four 100A of Lithium in 4p. My biggest concern is my Victron settings, I don't think the solar is prioritized as I am not using ESS or any agents. Are you no longer doing consulting?

[AndrewJohnson]

Thank you for this entire series. I've used your videos and @WillProwse videos and information to build my off-grid cabin system. It came out really well, if I do say so myself. I am now going to tackle our new motorhome conversion. A Tiffin Allegro Bus 45 OPP, which is all electric, 50 amp, with a 10k Onan generator on-board. Hoping to go 48v, as I did with the cabin, but using mostly Victron components, but also considering all-in-one systems like EG4. I used MPP LV6548 at the cabin, which has worked great. Only in the planning and spitballing stages currently, but look forward to a finished product that will be used for fulltiming when I retire next year. Thanks again for all of the great content!!

[joaobanza]

Great, great, great, great, great, great, AND CLEAR, video!
10 out of 10!

[rhiantaylor]

Worth stressing that for relay or switch contacts, the DC rated current will be significantly lower than the AC rating (for the same contacts). This is because AC current drops to zero 120 times a second which helps quench any arc formed but with DC current it just keeps flowing so you need some other way to make sure you do not wear out contacts from arcing.

[robbehr]

Good video! I'm currently running 12-VDC solar, but I'm upgrading to a split system: 1) 12-VCD for all of the things designed for 12 volts; and 2) A 48-VDC system for my ductless mini-split and everything else using 120-VAC.

[rockeyoliver]

Loved this video.
Myself, I’m going 24V / single 6000w dual split inverter (power to be used 110/12/24/48/240) Aims or Sun Gold Power Inverter.

My Cinderella Electric Toilet I’m going to use in my build needs 240v to operate.

So I’m going to use compact marine (Mastervolt 24V) batteries for 840 A/hr storage capacity.

So being a subscriber & learning from your channel along with other DIY has been a huge asset to me.

Looking forward to seeing your next video.

Keep up the great work!

Blessings to y’all.

[jensschroder]

For a remote garden shed, used on weekends in the summer, a 24V system can be a cost-effective solution.
There are also 24V accessories and lighting. It may then have to be a 12V DC lighting system.

[RollinHomies]

Thanks for the video! Hopefully no one tried to hold you accountable for their lack of research.😬
I installed a 24v battery system in our bus and still used 4/0 wire from main busbar to the inverter(s). Really, the money saved for thinner wire (in a 1000amp system) isn’t worth the possible bottlenecks that could happen. 🤘🏼

[goanddo]

Thank you Nate! I've been waiting for this video specifically. Extremely helpful