I did some study on the Alpicool C20 and it seems to implement at most 72Ah @ 12V for each 24h, that's 864 watt-hrs. I’d anticipate it to work with a bit less than that as it won’t be functioning the compressor https://kaleodel751309.blog-ezine.com/30635566/a-simple-key-for-best-portable-power-station-unveiled