Long time since I posted but I have a power wall set up. I used commercial lfp ul listed battery’s and a Schnider xw inverter (built like a tank
). I looked into the diy option and if you can put the battery’s outside in a dog house that’s insulated, cooled and heated it’s ok but I would not put a diy battery in or near a structure. A nice battery shed could work but I rather keep my home insurance
ul and electrical inspected and your good to go.