Not much to show - lots of nitty gritty detail work, wiring the electro cabinet and using the bad weather to do some soldering on the battery management system and programming. The necessary balancing for the LiFeYPo4 cells and the protection against under voltage is all controlled by an Arduino Nano board and shown on display with the voltage of all 4 single cells, the total voltage, the actual balancing voltage (as I use different charging sources the software detects the source and goes for the right balancing threshold). To protect against under voltage the software checks each cell for the lowest voltage, i programmed two levels - at 2.9V the fridge is cut off and the rest (lights, USB outlets etc.) follows under 2.6V.
due to much overtime @job not much done on the camper - finished the software for the Arduino, soldered the circuit boards and tested the setup, balancing works very well. To be flexible regarding the balancing voltage I added a variable resistor and modified the software so I can now easy adjust the balancing voltage between 3-4 Volt with a screwdriver.
today we got the camper out of the garage and put it with the help of my neighbor and his tractor onto the Ranger to bring it up into the barn for further build. I had to free the garage before first snow for our daily drivers.