Build a small powerwall

Hi there, I like to experiment with a small powerwall system. On that I can connect to a generator (for example a revolt generator) that is connected to a small Solar panel. I have a holiday house and I want to generate power to the generator and powerwall when I am away. That way I can use the power I made easily the one or two days I am usely there. At home i also have a 17x350wh Solar panels and like to build a powerwall there also eventually, but for now I like to experiment a bit. Did see a lot of manuals and video's, but before I am doing a lot of studies to onderstand what to do I like to have something of a 0.25-0.5kw system to experiment with. Can somebody build a small system for me? I know the prices of used lithium batteries and checked soms building sets at vruzend and stuff. Let me know!