Bought a van! Now what? 12 or 48 volt?

[Ariel188]

Hey, just so you understand, 48v system doesn't give you ANY more power than a 12v system! The only difference, and alllll the stuff we talked about, is it changes the wiring size, that is IT. 48v lets you run smaller wires, which makes it easier to do a 3000w inverter. But you can do it with 12v. But BOTH USE THE SAME TOTAL POWER!
Your system power limit comes from the 800w solar on roof limit. Or your 2nd alternator. And then how much batteries you have to store that for later use. Panels and batteries define your system power. If you thought you'd have more power from 48v, that is 100% false, same power as 12v. Just some easier engineering is all.

I think I may be liking your 24 v idea?? I can get the cruise n comfort in24 v as well as the cruise isotherm fridge is 12 or 24 in same unit. Is 24v still worth needing to get the step down convertors? Thank you Dave!

 

[k490]

She listed her desired usage, it is a LOT OF watts of power. And a good bit of ac power. Air-conditioning, washer, cooking devic

800 watts of roof space this won't be a big solar system just have to run those big appliances on a generator, or grid power. Running a generator for a few hours isn't really a big deal. I have seen people use the largest HF inverter generators in the desert through the summer run them 24/7 get the extra warranty replace them 3-4 times a summer. I don't know why they stay in AZ in the summer I would be heading north. Likely they can't afford RV parks up north. Could run one of those small suitcase Honda 1800-watt generators or a small Onan have it mounted in the van start up with a button push. Run your blender, or whatever on it short time.

 

[Dave in AZ]

I think I may be liking your 24 v idea?? I can get the cruise n comfort in24 v as well as the cruise isotherm fridge is 12 or 24 in same unit. Is 24v still worth needing to get the step down convertors? Thank you Dave!

24v gives same amount of power as the 12v and 48v system, same amount of electricity stored in your batteries. But yes, it does cut the amps current flow in jalf, letting you use smaller wires and also easily supply that inverter without any issues.

I THINK you're asking if you would still need to get a step down converter to go from 24v to 12v, to supply some things. Only thing on your list was the rixan diesel heater uses 12v. Maybe a fan if you have one of those maxxair or fantastic fans in ceiling, the standard good ones. LED lights and personal fans all come in 12v AND 24v, on same device, for cheap. USB ports for laptops etc can be run off 24v, just buy the right ones. So... yeah, you probably do need a small step down converter. You probably don't need much 12v, 30A converter would do as your diesel would use 12A max at startup. Not expensive, $30 to $150 and an easy part to add, in fact you can just add the converter and also a $30 BlueSea dc fuseblock and just hook all your 12v stuff to there.

You could go Cheap and get a $30 one, or the Victron top of line for like $150. I like the victron as you can tweak output power to 12.8 or 13v, which ensures smooth diesel heater operation with no power issues folks get on cheaper power stations.

So yeah, 24v system gives you 12v also with 2 inexpensive small boxes, less than $200 total and you get best of all worlds.

 

[Pierre]

I think I may be liking your 24 v idea?? I can get the cruise n comfort in24 v as well as the cruise isotherm fridge is 12 or 24 in same unit. Is 24v still worth needing to get the step down convertors? Thank you Dave!

Lots of good advice on this post. I would suggest starting with as much solar pv as possible. Ever considered a double stack pv array where the bottom section slides out when stationery ? You can use rigid panels for the top tier and flexo panels for the bottom tier. This will make the slide portion lighter , less space required and easier to manage. My motto is that you can never have enough pv. I assume that your setup will allow for 2way ( pv & alternator ) charging when on the move.

 

[Dave in AZ]

Lots of good advice on this post. I would suggest starting with as much solar pv as possible. Ever considered a double stack pv array where the bottom section slides out when stationery ? You can use rigid panels for the top tier and flexo panels for the bottom tier. This will make the slide portion lighter , less space required and easier to manage. My motto is that you can never have enough pv. I assume that your setup will allow for 2way ( pv & alternator ) charging when on the move.

She is getting a 2nd alternator and has solar. But hey, tell me about this double stack solar, is this just something you made up in your head or can you post a link to a viable product? She stated a few times her van is being built by someone, she isn't gonna weld something up here...
I'm interested to see a link to double stack rack for my own use also, lookimg forward to it, thanks!

 

[Pierre]

She is getting a 2nd alternator and has solar. But hey, tell me about this double stack solar, is this just something you made up in your head or can you post a link to a viable product? She stated a few times her van is being built by someone, she isn't gonna weld something up here...
I'm interested to see a link to double stack rack for my own use also, lookimg forward to it, thanks!

Lots of rv builds on the internet using this idea. She has to have a frame made to accommodate the panels so why not just add a slide-out panel at the bottom.

 

[Ariel188]

24v gives same amount of power as the 12v and 48v system, same amount of electricity stored in your batteries. But yes, it does cut the amps current flow in jalf, letting you use smaller wires and also easily supply that inverter without any issues.

I THINK you're asking if you would still need to get a step down converter to go from 24v to 12v, to supply some things. Only thing on your list was the rixan diesel heater uses 12v. Maybe a fan if you have one of those maxxair or fantastic fans in ceiling, the standard good ones. LED lights and personal fans all come in 12v AND 24v, on same device, for cheap. USB ports for laptops etc can be run off 24v, just buy the right ones. So... yeah, you probably do need a small step down converter. You probably don't need much 12v, 30A converter would do as your diesel would use 12A max at startup. Not expensive, $30 to $150 and an easy part to add, in fact you can just add the converter and also a $30 BlueSea dc fuseblock and just hook all your 12v stuff to there.

You could go Cheap and get a $30 one, or the Victron top of line for like $150. I like the victron as you can tweak output power to 12.8 or 13v, which ensures smooth diesel heater operation with no power issues folks get on cheaper power stations.

So yeah, 24v system gives you 12v also with 2 inexpensive small boxes, less than $200 total and you get best of all worlds.

Thank you so much for this dave. I'm going to research it more. As well as the ricks and heater I'm hoping they might come in something other than 12v. I don't skimp on anything I will buy the best so I plan to probably have all victron. And I'm still undecided on the batteries it seems like will thinks that battleborns are really overpriced for the stats. They have those game changer ones I was thinking about getting three of them but I really don't think I want to spend $7,500 on three batteries unless they really are the best and don't drain fast and fill up quicker or are somehow more special than other batteries of the same amperage...... I was told the rack batteries aren't very good I was originally looking at those...any suggestions? Thank you very much!

 

[Dave in AZ]

@Ariel188 the batteries are all the same pretty much as to how fast they fill up, and exactly the same as to how much power they hold, that is whatever the label says. So, if you were to go with a 24v system, I would probably get 2 batteries each 24v, and run them in parallel. That gives better battery health, balance, and a nice backup--if one battery dies, the other still works and so does the system. I can't recall how much battery you planned.

In any case, what you get with a more expensive battery is:
-- better build quality, better quality Battery Mgt System BMS, better fault protections, maybe Low Temp Protection so they dont charge below freezing, and maybe self heating to avoid that.
-- A U.S. distributor you can actually call when issues, instead of a Chinese phone number.
-- buuuttt... you can get good build quality cheap batteries watching Wills teardown and test videos, the BMS are most all good now, the Victron or other chargers all have low temp protection built in, and you can keep van warm or heating pad. And never buy cheap batteries direct, only via Amazon so you can return them.

Battleborn not worth it IMO anymore, with Lithium Iron Phosphate (LiFePO4) prices so low... you can get a new one for $400 or something in a day or so. With a parallel battery system, it still works, swap out the battery. But I defer to van builders here, I have no experience with different hi cost batteries. But I know I can get 4x as much battery power from LiTime as from battle borne for same price.

Here, you may like this neat calculator to help you estimate power use. It autofills in what this vanlife guy uses, it works, just putz around scrolling down until you find the buttons. Also click on some of his articles up top, on menu, he has ones for all your van build.

Van Electrical Calculator - FarOutRide

Find your power usage, automagically size your components (battery bank, solar, etc.), retrieve your customized items list and wiring diagram. Easy!

faroutride.com

 

[Isaac-1]

Lots of rv builds on the internet using this idea. She has to have a frame made to accommodate the panels so why not just add a slide-out panel at the bottom.

Weight considerations are an important factor in any such van build

 

[RV8R]

Hello everyone!

So I plan to have a large build in my Sprinter 170 ext dually.

I an planning on this build (done by my van builder who has only done 12 volt small systems....)
On roof 700-800 watts of walkable solar panels. https://www.custommarineproducts.com/semi-rigid-walk-on-marine-solar-panels.html
and 800-1200 amp batteries (dont know which one yet.)

I wanted to do 48 volt but everyone is saying I should do 12.....I am confused I need more opinions please.

I will have rixan diesel heater, cruise N comfort AC at 12 or 48 volt, induction stove, breville oven, washer, use a vitamix blender daily, instapot, food processor, gaming computer, I plan to buy a SECOND alternator (280 nations) so I need a system that will charge as fast as possible with the second alternator. I will also have shore power connection, and even EV charger port. I will be hiring a builder to build my van and do the solar. He has never done a 48 volt thou. I have allocated 20K for my solar system (but would love to NOT spend that much, to have an amazing system that is limit less) so I never have to struggle again with power like I do now in my 42 ft RV with 48 volt put in by someone with no experience........ Thank you for the thoughts, advice, and opinions to help a girl out! ;-)

Hi @Ariel188

DIY Van Building has become a weird hobby / obsession for me. I have designed & built out two Promaster vans for ourselves since 2018. I am a retired Building Science Technologist from a 4 decade career.

If this is Your 1st Rodeo building out a van, I understand why you are seeking opinions. The best decisions are made from a good knowledge base. Acquiring the knowledge from the internet if you do not have a Building Science background is extremely difficult. Why ?‍, because a person in that position can not separate FACT from BS.

I have not read thru this entire thread, but my suggestion is you slow down & acquire some knowledge / facts & complete or complete as far as you can your design before buying anything or starting the build.

I am going to start my 2 cents here for you with this “incase you don’t know”. I coined a phrase for van design; “All Things Heat ( & Air Conditioning )” They take a lot of Energy.

Next; 1 - 20lb Propane Tank ( Standard BBQ Tank ) holds as much Energy as 116 100Ahr 12vdc LFP Batteries ? To put these “Energy Storage Tanks” into perspective. 1 Tank holds the same as 116 Tanks ( 1 vs 116 ).

All of these RV Electrical Systems will come down to “The Big Question” & that is “How Are You Going to Charge Your Batteries”.

Lastly; Electrically Speaking ,,, Sprinter, Transit, Promaster, Etc it is all the same with the exception of “The Alternator Charging”. That is vehicle specific.


Diesel You Say ? There is the Dual Wallas;

XC DUO – Wallas

 

[Billy D.]

I read post #26 carefully. I've lived in a van and an RV. If you are having trouble understanding and maintaining your existing system, then go for a small, dead-reliable 12V system with the best components and the best workmanship possible. Then get the best operational understanding you can for your specific setup.

48V saves on wire, adds some efficiency, and the batteries are better. All of that sounds appealing but it's not for everyone.

Try to bring your numbers down to 2000W (the highest draw from all the gizmos that you expect to run simultaneously), and run 12V. Learn to live with it. You'll be glad for it. It's safer to work with, and there's greater availability of components.

When money is available, we want creature comforts. It's easy to dream big. Too big. It introduces more problems. The simpler and smaller your system is, the easier it'll be for you to understand and maintain. Small and working is better than big and broken. A Camry on the road is more useful than a Bentley in the shop.

Figure out your absolute bare essentials, and be really honest with yourself. RV living is about being practical and realistic, not luxurious.

I've seen some (certainly not all) van outfitters go way beyond the limits of practicality because they have an enthusiastic customer with ample cash. The builder wants to play with new toys so he can put it in his résumé. "The new hotness" is not a reason to do something, especially in a mobile application. You want the opposite; tried and true. If you live in it, and you aren't making a ytube about it, then stick with simple design and learn to enjoy the reduced complication.

-Devil's Advocate

 

[RV8R]

Hello, wow thank you so much for your very detailed explanation I really appreciate it even though it's over my head and I still really don't understand a lot of it. I am actually in the USA in California I'm just a dumb girl with electrical and I have no idea what the abbreviations mean. I'm more of an aesthetic person with design but not the background of what's behind the Walls LOL

Once I get my Internet working again I will watch all the links thank you so much I'm sure I'm going to have a million more questions. I really just love to have somebody design me a system that would work for me.
I'm actually in a 42 ft RV right now and it's been a living nightmare for the last 15 months. It's all victron and a 48 volt system but it's for chin batteries 300 watts each and they are tied in series to make a 48 volt but I found out later it needed battery balancers that were never put in so I had somebody come do that but I did not help

I'm off grid here and the Onan generator is constantly breaking I have a guess that the inverter settings talking to the generators not correct and I only have a Mac laptop and you need a regular PC to hook into the victron inverters.

So alas I am struggling with the power and constantly turning off on me and the generator shutting down with code 15 and code 36 all the time I've had so many people out here and no one can seem to figure out any of this. It's very distressing I sit in the dark and cold a lot this is what I want to avoid a million percent in my van and I will spend whatever I need to so that I can make sure I will have plenty of power and no more BS like this. This rig is too big to move, and I'm in a rural area with not much help for people to fix things. Big reason why I'm getting the van so I can drive around myself and get help if I need or what not.

So that's why I'm desperate to have a really good design system that will not fail me and shut off and break and I don't know how to do any of this or fix any of it so I'll spend what I need to to get it done right and I don't want to make bad choices on what parts to get because I don't know what the heck I'm doing......

Hi @Ariel188

Your Statement;

I really just love to have somebody design me a system that would work for me.

Well, I am not sure where you are located ,,, But Your Avatar looks like “The Golden Gate Bridge” to this Canadian ?‍.


If so You have a Gem of a Guy who could design ( & Build ) Your system ( Near San Francisco ). He is @HarryN

Look @ Post #25 just above your post #26 ?

 

[RV8R]

I read post #26 carefully. I've lived in a van and an RV. If you are having trouble understanding and maintaining your existing system, then I suggest setting up a small, dead-reliable 12V system with the best components and the best workmanship possible. Then get the best operational understanding you can for your specific setup.

48V saves on wire, adds some efficiency, and the batteries are better. All of that sounds appealing but it's not for everyone.

Try to bring your numbers down to 2000W (all gizmos that you'll actually run simultaneously), and run 12V. Learn to live with it. You'll be glad for it. It's safer to work with, and there's greater availability of components.

When money is available, we want creature comforts. It's easy to dream big. Too big. It introduces more problems. The simpler and smaller your system is, the easier it will be to understand and maintain by you. Small and working is better than big and broken. A Camry on the road is more useful than a Bentley in the shop.

Figure out your absolute bare essentials, and be really honest with yourself. RV living is about being practical and realistic, not luxurious.

I've seen some (certainly not all) van outfitters go way beyond the limits of practicality because they have a customer with cash. The builder wants to play with new toys so he can put it on his resume. "The new hotness" is not a reason to do something, ever, especially in a mobile application. You want the opposite; tried and true. If you live in it, and you aren't showing off on ytube, then stick with simple design and learn to enjoy the reduced hassle of needless complication.

-Devil's Advocate

Hi @Billy D.

There is a Ton of Wisdom in Your Post ??

This is a gem;

Small and working is better than big and broken. A Camry on the road is more useful than a Bentley in the shop.

Your Words resonate with me as Someone who; has been there, done that, & afterwards considered things ( mulled it over ).

I also am a believer in “Simpler is Better”. I hope others read your post & understand what a gem it is !!