Confused..aH at 12v or 24v?????

[Rbertalotto]

I currently have two 100 aH 12v batteries in parallel running a 1000w Xantrax 12v inverter in my travel trailer. So my system now is 200aH. Im looking at “ All In One” 3000w, charger / converter and a server rack mount battery system for my next camper. Choices are 12v, 24v, and 48v….I understand the wirecsize issue and savings as I move up in voltage. But the battery and AI1 will be 12” from each other.
What the advantages of higher voltage in this situation?
Thanks

 

[BobH]

One overlooked area, depending on the brand of equipment and the specs on the solar panels, is that higher voltage systems use smaller and less expensive solar charge controllers. I went with 24v Victron system in my RV and that saved several hundred dollars in the SCC price. Even after having to add a 70A 24v- 12v converter to supply my 12V equipment.

 

[JJJJ]

If your lighting and appliances are 12v then the advantages for 12v and 24v are less pronounced. If you will be going with 120v then 48v seems to be the current sweet spot. Smaller wires and a growing list of products which support it

With higher volt systems it is still possible to step down with a dc to dc conversation.

 

[justinm001]

48v SOK batteries with a Victron inverter. With 48v there's a much wider range of acceptable voltages and everything just works so much better because there's virtually no losses.

There's not a ton of 48v stuff but it's growing and there's some 48 to 12v converters. This does offset your wire savings a bit.

4/0 wire is rated for 230a (260a at 90c) so it can't really handle your inverter. It's so much thicker and harder to deal with and adds heat.

 

[JJJJ]

4/0 wire is rated for 230a (260a at 90c) so it can't really handle your inverter. It's so much thicker and harder to deal with and adds heat

Having worked with 2/0 wire I can only guess how much fun it is. Especially in tight spaces.

 

[GXMnow]

What is the normal running power going to be? My quick rule of thumb is to keep the normal running current under 100 amps. If your system will normally be under 1,000 watts with occasional peaks to 2,000 watts, then a 12 volt system is going to work just fine. If your normal running power is up to 2,000 watts and peaks to 4,000 watts, then I would say 24 volts is your minimum recommended system. And if you will be running 4,000 watts often, and peaking high, then 48 volts is really the only choice.

After you figure in losses and inverter efficiency 100 amps at 12 volts will provide you with a solid 1,000 watts, 2,000 watts at 24 volts, and 4,000 watts at 48 volts. And similar numbers also work going the other way from the charge controller(s).

 

[Rbertalotto]

Thank You…. But Im considering an All In One s unit that has Solar CC, inverter and battery charger. The only heavy wires will be between the battery and the All In One….from there it will be 120v wiring and a converter from “X” volts (24v?) to 12v for 12v devices in the trailer. Solar panels wiring will need to be designed for available roof space and final voltage….Am I missing anything here?

 

[Aussieguy]

if your all in one is designed for 24v or 48v
you have to have a battery bank that is 24v or 48v

if you want to run the 12v appliances in the RV you have to get a 12v step down.
the new step down has be powerful enough to run some of the heavy stuff like slides..
OR you can also still have a separate 12v battery ............ as well as the 24v or 48v

lot of work for little gain
the trailer/RV is already wired for 12v ...
just keep the distance between inverter and battery as short as possible

unless you got a real big RV you won't be carrying enough panels to make the extra work worthwhile
if you do have a lot of panels simply adding one or more solar controllers to harvest more watts would be better alternative.