TurnThePage wrote:
I'm very near to picking up a new travel trailer that I intend to pack with solar and LiFePO4 batteries. It's a 30A 120VAC RV. I understand the electrical wiring advantages of the higher DC voltage configuration, but what does everybody do with their 12v appliances?
I'm hoping for around 1500 watts of solar and no less than 1000Ah of 12v batteries. Is there a good reason not to stick to a 12v configuration?
you have to keep the 12V apliances but use a step down converter to run them like some one mentioned already.
my question is what do you think your going to gain by running a 48V storage setup over 12V setup? you said your not worried about inefficiencys but is the very slight increase in efficiency you gain with the lower amprage levels nd higher voltage levels between your battery and the stepdown converter worth it? on the AC side its the same thing but you can offset that by proper sized wires between your batteries and inverter.
with the money you save not buying a 48v to 12V inverter converter you could buy a 270ah battle born battery.
if I was going to do your system I would get four of the 270AH dragonfly/battle born batteries which ever you can get cheeper (who am I kidding if it was me I would just build my own but thats not the pourpose of this post) then I would get a good inverter to meet the needs of what you need to run and mount it right beside the batteries. for solar panels that is where I step the voltage up and run 24V panels in series as thats the longest wires in the setups.
in a home solar storage off grid set up I can see spending the money on a 48v set up as you are running a lot higher of an inverter output and the wires from the battery bank to the inverter would just be stupid, but 9 time out of 10 your never going to need larger than a 3000watt inverter in a rv using 2/0 cable you can handle 300amps at a distance of 10 feet, so there is some safety built into that as you should cut the distance down in half and a 3000watt inverter will draw about 250amps when running full out (plus a little for inefficiency.) on the other side a home system may be running dual 5000 watt inverters (or more) to provide 220V power and run the whole home so on that scale and size the cost difference in wire and the amount of amps involved makes it benificial.
I just don't see it in a rv set up, but thats my thought, if you have a different path of reasoning I would love to hear it as maybe I am missing somthing.