Goods Scene Troubleshooting
iRobot Charging Error 121 – Robot docks but cannot maintain charging
Charging Error 121 means the robot docked but was unable to charge or was losing charge while docked.
Issue meaning
What this issue means
Charging Error 121 means the robot docked but was unable to charge or was losing charge while docked.
Start here
First checks
Clean the charging contacts on both the robot and dock, reseat the robot on the dock and retry.
Inspection
Area to inspect
Robot and dock charging contacts, seating and charging stability.
Goods Scene guidance
What to do next
Intermittent charging while docked often points to contact quality or alignment. Confirm those before diagnosing the battery or charging board.
Practical guidance is kept separate from manufacturer wording.