Hi, I have been researching on how to set up my RV (as it needs new batteries) I will be installing LifPo batteries so the first question I asked myself was do I keep it 12V or go 24V? I would like to go 24 as it is much more efficient and one is as good as two 12’s. So the next issue is I will need a step down converter to run the RV’s 12V lights, jacks, fridge, awning and other stuff. So which one? How big? I have picked the V E Orion IP20 24/12-Volt 25 amp, not knowing if that is enough. So is it as simple as connecting the RV to the output side and the battery to the input side? I am thinking I will have to replace the charger or charger/converter to charge the batteries, or maybe all I need is a charger? My converter charger is simply a Progressive Dynamics deck style (55 amp). Eventually I want to add a large inverter so that is why I am thinking 24V as it will be more efficient, that will of course have a charger built in, my RV is split phase 50 Amp so another level of complexity gets added. Anyone ever done this? have a diagram? suggestions?
We do it daily in the shop. Any RV or mobile system with an inverter 3kVA and larger goes 24V to keep the wire sizes down. Our typical DC-DC converter is the Orion-Tr 24/12-70. It’s inexpensive and provides up to 70A for 12V loads.
To replace your converter you could use an IP43 24/25 smart charger. But, as you said, for not much more money you could eliminate the need for a converter and install a MultiPlus-II 24/3000 2x-120V instead.
Why don’t you directly go to 48v for the storage batteries?
In larger systems we do. Until recently, however, Victron didn’t offer much in the way of DC-DC chargers from 48 to 12 or 12 to 48. But, the biggest reason is the voltage required to charge 48V batteries on small RV’s (caravans) that can’t fit enough solar panels of suitable size to reach about 62VOC. 24V is a sweet spot for smaller vehicles or motorhomes. Now that Victron offers some DC-DC chargers for 48V, though, this is less of an issue.
Yes I understand, I was thinking the 70amp step down after I posted based on the fact the current ch/con is 55amp. But, all that said, I cant do it all at once so I realize I may have to duplicate a purchase when it comes to charger but I can use it as a back up or for something else. What do you think of this? Buy a 12v house battery and keep that all as is and when I decide to install the inverter have that 24v as a separate system? Or would that be too complicated again? I appreciate your help.
$$ mostly, and if solar is in the future it’s tough to get that much solar on an RV to charge them.
Per Wh 48v is cheapest, I’ve got 800Wp on my tiny 36’, making room for 140w more…
It’s about upfront $$ not per watt, then the chargers, inverters and everything else is more and not readily available where I am.