48 volt system in a motor home

[FJG]

I have a 2015 Newmar 43ft motor home, I would like to install a 48volt system. I am concerned about the 12volt needed for running the hydraulic leveling system and 12volt electric slide out motors. I know that 48 to 12 volt power supply could be used, but the power draw is large.
I could install multiple to get the amperage but if they would fail, we would definitely be stuck. Any advice would be appreciated.

 

[hwy17]

Dual systems, 12v for the existing 12v systems and 48v for AC power inverting. And then the appropriate systems to cross charge between them.

 

[Vigo]

I think the best thing to do is keep a 12v battery for the brief periods of large draw (such as using the jacks or slideouts) and then have that charged by a more reasonably sized charge source, either a 48v>13.8v step down converter, or an AC battery charger running off the 48v inverter.

The 12v battery will also still be charged by the tow vehicle through the 7 pin trailer connector.

I think all the trouble comes from trying to not have a 12v battery and power those items directly from a step down converter or 12v power supply. In my opinion it's very much a good idea to keep an actual 12v battery in the system.

 

[OffGridInTheCity]

I did a 7 x 14 cargo trailer -> camper build-out on a 48v system (using MPP Solar 3048 LV). So I have a 120vac 'base system' and get 12vdc from it.

Here's a 50a example - https://www.amazon.com/EAGWELL-12V-Power-Supply-Transformer/dp/B09NVX48NT/ref=sr_1_2 - and they offer 30a to 82a. Not pushing this brand, just showing an example - there are many options.

I have an 80a for the main 12vdc sub-system and a 2nd 30a out in the front cargo box for the 12vdc powered tongue jack (because I had easy120v access out there rather than 12v). Both are in their 4th year of camping and no issues of heat of damage due to road vibrations or temp extremes.

As far as I can tell, these units are *very efficient* and don't have large idle power draw so you don't loose much by doing 120vac -> 12vdc. A secondary thing I like is that everything goes thru the 120v system, so I only need to monitor power use on the 1 system - e.g. don't have separate 120vac and 12vdc systems.

 

[yabert]

Many 48-12V DC-DC https://daygreen.com/en-en/collections/36v-48v-to-12v
I never use those, so I don't know quality, but they are affordable at least.