48V is a common system voltage in a variety of commercial and industrial power applications. It's right at the threshold you have to accommodate any shock hazard, so wiring and connections are not as tightly spec'd. There is a ton of 48V bus compatible equipment out there, so there's some economy of size and scale already in place. For a given power, the current is lower than 12V so wiring and control devices are smaller and ostensibly less expensive. Since inverter/converter efficiencies at any voltage conversion are typically pretty good, then generally you want as high of a source voltage as you can get to minimize resistive losses. For something like an off-grid 120VAC home this bank voltage is a slam dunk and you will find lots of 48V solar/storage solutions for this. The fly in the ointment for RV's is that many things natively run on 12V and it's usually more efficient to run them directly off of a battery than through a converter. If one was super motivated you could replace all 12V equipment with 48V and enjoy a slight boost in efficiency but it would be a pretty specific application to make that degree of refit practical. 42V SLI batteries have been proposed in the auto industry for years, but even at that scale it's been tough to overcome the inertia of systems that are developed and proven. Even in an EV with a high voltage traction pack and any operating voltage you could want through conversion, you still find a 12V chassis battery and accessories. But if you have a chance to start with a blank slate with a power storage or distribution system, using 48V is what you want over 12V.
Mark B.
Albuquerque, NM