EcoFlow built this device to past for a longer period. it's got an LFP(LiFePO4) battery chemistry using a portable power station and 6500+ cycle life.
Be aware that I've paired the Yeti with 400W of photo voltaic https://kathrynphsm256222.thenerdsblog.com/35122267/a-simple-key-for-best-portable-power-station-unveiled