Goods Scene Troubleshooting
iRobot Charging Error 21 – Robot docks but loses charge
Charging Error 21 indicates that the robot is docked but is losing charge instead of remaining charged. Charging-contact maintenance is a common cause.
Issue meaning
What this issue means
Charging Error 21 indicates that the robot is docked but is losing charge instead of remaining charged. Charging-contact maintenance is a common cause.
Start here
First checks
Unplug the base briefly, then clean the metal charging contacts on both the robot and dock. Confirm the base power connections. If the error remains, remove and reinstall the battery securely.
Inspection
Area to inspect
Robot and dock charging contacts, base power and battery seating.
Goods Scene guidance
What to do next
Rule out dirty or damaged contacts and a loose battery connection before diagnosing the battery or charging hardware.
Practical guidance is kept separate from manufacturer wording.