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Roomba Charging Error 8: battery communication fault
Charging Error 8 means the robot cannot communicate reliably with the battery.
Start here
Charging Error 8 means the robot cannot communicate reliably with the battery. Reseat the battery, verify it is authentic/compatible, then clean the charging contacts.
Check these first
- Reseat the battery.
- Confirm battery compatibility/authenticity.
- Clean robot and dock charging contacts and check for damage.
Fix it in this order
- Remove and reinstall the battery.
- Retry with the correct genuine battery if an aftermarket pack is installed.
- Clean the external contacts and dock again.
- If Error 8 persists, service the robot/battery communication path rather than replacing more random accessories.
Evidence to keep
- Battery brand/part
- Cross-test result if available
- Contact photos
- Error recurrence timing
Do not make it harder
- Assuming any same-voltage battery is compatible
- Opening the battery pack
- Replacing the base before testing the battery/robot relationship
How you know it is fixed
- Battery is detected and charging proceeds without Error 8.
If the obvious fix does not work
- If a genuine known-good battery works, replace the bad/incompatible pack.
- If two known-good batteries fail in the same robot, the robot-side connection is the stronger suspect.
- If the same battery charges in another compatible robot, record that result for service.
If this still isn't resolved
- iRobot support with cross-test results
Sources for this path
Use these references to confirm provider-, model-, policy-, or jurisdiction-specific details before an irreversible step.
Need the complete context?
This page solves one branch. The parent guide covers the full decision, edge cases, alternatives, and related checks.