WT Hell is 48 volts all about

[bagmaker]

Dont reckon I would bother with 12v on a clean build, keep the std DC electrics separate for the rig, 48v lithium/panels driving a decent inverter only. 240v everything else like a house. LEDs are cheap with plentiful designs, all the appliances are standard etc. I cannot think of much that actually needs to be 12v (or 24v) for a motorhome fitout.

1- diesel heater (probably run it off the standard bus electrics with a decent 240v internal charger topping off the batts)
2- ?
3- ?

[Vik351]

Hi bagmaker, my son prints em for ya... works for Rodney...!!!

Blimey, so thats another track to think about, from scratch, but mines an existing 12 volt humpy and 12 volt stuff

Sounds like the new trend though, for those in the know that is...

vik...

[jon_d]

I'd do 24 Volt house.

Most of the led stuff and electronics you can get is 12/24. I really haven't seen any 48V stuff. The only thing that would use it (48) is the inverter and at 24 volts,

2.4 kwatts is only 100 amps @ 24Volts and 50amps@48Volts. (Is it worth the level of difficulty sourcing all the other parts??)

[Mrcoolabah1au]

🌪🌪🌪

[Vik351]

I'd do 24 Volt house.

Most of the led stuff and electronics you can get is 12/24. I really haven't seen any 48V stuff. The only thing that would use it (48) is the inverter and at 24 volts,

2.4 kwatts is only 100 amps @ 24Volts and 50amps@48Volts. (Is it worth the level of difficulty sourcing all the other parts??)

OK, if I went that track all my stuff is 12 volt, SO would that mean (novice remember) all the solar stuff at 24 volts and the battery's, so I get killer solar and storage then reduce the juice to the house to 12 volts...???

Or does each item need a reducer(must be a proper name ???) to 12 volts

Loving all this,thanks all, stuff I never even knew of to even think about...

Gunna be a long chat with Terry soon...!!!

vik...

[Vik351]

🌪🌪🌪

Your post vanished...???

vik...

[bagmaker]

If all your stuff is 12v then stick to 12v.
I have issues with all three, 12, 24 and 240 volts.
In your case I would be inclined to ditch the crank battery and run the starter/bus system on a house lithium 12v.
Then run a larger, quality inverter at 240 for all your house needs.

Just my 2c, based mainly on high usage appliances being better nowadays on 240 compared to 12.
The lighting, pumping, fanning, etc -all could be done easily with 240v.
The A/C, fridge, freezer, water heating, TV, etc should all be 240. So instead of running heavy 12v copper everywhere, run a suburban house system.

The 48v thing is tapering towards suburban style panels and inverters. I would go that way with a 24v based bus, negating 12v. But in your case Vic, since you are 12v anyway, prolly best to stick to 12v and tap it for running the bus as well.

Of course this is all pie in the sky, most of us get a horror mismatch of 5, 12, 24 and 240v. Thats what you try to avoid if lucky to start from scratch

[Busman]

Or do what we did, after destroying a few DC to DC step down convertors, we simply added a 12 v lithium bank as well, at 200 Ah.
Then of course we had problems charging that, so after destroying quite a few elcheapo chargers spent the bucks for a Projecta and haven't looked back.

[jon_d]

Vik

If you already have the appliances, stick with 12 volts.

I originally started the fit out planning on 12volts but switched to 24.

The batteries and solar is set up for 24.

heater, lights, inverter and most other things are 24.

The water pump and gas cook top and gas water heater electrics is 12. (using a lillte converter for both) They are 12 becuase I had collected them before deciding to change to 24.

[native pepper]

Vick, there are a couple of ways you can go, depending on the type of solar controller you get. If you go with a PWM controller, you will be stuck with using panels and equipment of that voltage. If you go with a MPPT controller, you can have 24-48v panels on a 12v system.

The reasons for going 24v and higher in RV's using lifepo4 seems to date back to the use of lead acid batteries and their low usable voltages, so you need higher system voltages to compensate for loses when moving power around.

With lifepo4, all your real usable voltage is between 13v-14v and the majority is between 13.4 and 13v, so you have less voltage loss over a distance. Today, 24v solar panels which are mostly used on off grid homes, are cheap and can be run through a 12v MPPT controller, so you lose nothing from the panels to the controller and if you wanted to you could put your panels in series and put higher voltages through mppt. A Pwm controller requires set voltage panels to match the controller voltage

The availability and cost of 12v is dramatically lower than higher dc voltage appliances. When you add 12v psw (pure sine wave) inverters are readily available anywhere and cheap, compared to higher voltage inverters. So whatever voltage you use, 12V or 24v, as has been suggested, you can go fully 240v, but would need a qualified electrician do the installation.

With lower than 50v dc, there are no qualifications needed and you can do it yourself including repairs if you wanted to. The only thing you won't save on is wiring, as they need to be adequate for all sections of the system, the bigger diameter the wiring, the less loss of energy.

Except for 12v lights, radio's, pumps, and phone etc charging, everything we use is 240v through an inverter. Because 12v equipment is so cheap and reliable, you can carry spares of everything and pick up things just about any where round Aus. We carry at east 2 extras of everything, but have yet to need them and have 3 spare inverters in the bus and a couple of controllers. I've seen 12v inverters and small controllers for sale in some of the smallest and remote places, but rarely higher voltages and available range of appliances is important.

Going over 24v in an RV, is overkill today, whereas a decade ago it would probably be worth it for efficiency and reliability. I've been off grid since 1976, been using lifepo4 for over 10 years and my 700ah lifepo4 house system will be 10 years old next month. I have 24v panels and 12v inverters, with never a problem and it is all 240v.

When you get to talk to Terry, you will probably understand much better which way to go, the only thing we differ on, is control systems. I had dedicated lifepo4 solar controllers built and use just those and an active cell equaliser on my packs, which work excellently. Terry has his own system, which have yet to see.

From my experience over the last 10 years with lifepo4, they are wonderful and so far there has been no lose that I can detect in their capacity, but they never go over 14v when charging and never below 13v, even though they are set to go down to 12v before being disconnected. This all revolves around charging techniques and voltages, which is something you should learn about and expect Terry will guide you on the right track there.

Do your due diligence with the economics, availability and reliability of all voltage systems, before you make a decision. It can seem complicated and confusing at first, but when you go further down the lifpeo4 track, it will become much clearer and make your life on the road so much better when you finally sit back and enjoy the ride.