EZVIZ PS600 Power Station, Up To 600w AC Output, £0.23 / Wh 2 Years Warranty – Sold by Direct Smart Home UK

Three illumination options Nine ports across five port types
Cheapest power station per Wh price, big enough to survive all day in camping or blackout, light enough to move in backpack.
Seller is official EZVIZ seller, this mean 2 years warranty.
Yes, older type of cells, but still about 1000 cycles to 80% drop, so as long you not use full capacity daily it will be for years.