eufy robo vac 11 dead, not working, red light with 4 beeps while charging, unexpectedly stopping fix

eufy robo vac any model having below issues can be fixed by method showing on video/bypassing battery circuit/jumpering battery circuit,
4 beeps and red flashing light-not working
4 beeps and red stable light - while charging - in between charging - device works
no beeps no errors works as normal- soon battery low indication appears
no beeps no errors works normal but stop suddenly nowhere or while applying load - no power no led no beeps - to work again switch should be off and on again or keep in charging base manually.

for above mentioned all problems the culprit is battery pack, some times battery itself or battery charge controlling circuit, so first check the battery even if u full charged battery and still showing any of errors above then bypass battery charge control/protection circuit inside battery pack , but do that only by your own risk, that circuit there is for a reason for your and device safety.