Just as a note pressure cookers like the Instapot are rated at 1000wh but they don't use that all the time IIRC — only initially when building the pressure. In simple terms it's like using 1kw for 10 - 15 mins and not an hour. So on average very efficient.

Has someone measured the time for max usage and average usage? Could be a good alternative with a 1kwh lfp battery with a lot of juice left over after pressure cooking(no pun intended)

Rated at 1000 watt hours?

I used my Instapot ONE time as a hotpot thing, keeping a broth hot, almost cooking, for 2 hours with no lid. It died that day (thermistor).