I built a DIY LiFePO4 270ah battery in a box. It’s worked great over the last year or so. A little more involved than a deep cycle in a case but it was not hard with all the information available online.
The only direct connection is the diesel heater so if needed I can just bring the battery and heater without the truck. The main power connects to the camper with an Anderson Connector.
See this post for more specifics Show me your solar set up - #43 by Chuck.D
You can see the battery in this pic. It’s mounted below the panel. Everything is sealed up and can be quickly removed without tools.
