We started to get some random errors with our Eufy 11s which typically indicates the battery may be going.
Took a chance and ordered this replacement to address... And it did. Installation relatively easy... Turn off, remove couple screws, unplug old, plug in new, put screws back, turn on. Has been charging and working flawless since. Longevity ... Time will tell but normal life span of even OEM battery seems to be 1-1.5yr.