Check the record: The Roomba reports Charging Error 8
Confirm that the app or voice message actually says Charging Error 8 and note the Roomba series/model before changing the battery.
Take the next step: The Roomba reports Charging Error 8
Open iRobot’s charging-error guidance for that model. Reseat only user-removable battery components if the official instructions for the model say to do so, and inspect for obvious battery or contact damage.
Confirm the resolution: The Roomba reports Charging Error 8
The robot recognizes the charger and completes charging without returning the same error.
Escalate with evidence: The Roomba reports Charging Error 8
If Error 8 returns after the documented contact/reseat checks, stop repeating resets and contact iRobot with the model, serial number and exact error. Do not open or rebuild a lithium battery pack.