← Full guide: Roomba Charging Error (Check the Code Before a Battery Swap)
Roomba Charging Error 4 or 5: no or low charging current
Charging Errors 4 and 5 point to too little electrical current reaching the robot. The quickest split is dock power → contact condition → battery reseat.
Start here
Charging Errors 4 and 5 point to too little electrical current reaching the robot. The quickest split is dock power → contact condition → battery reseat.
Check these first
- Confirm the outlet and dock power cord are firmly connected.
- Clean robot and dock charging contacts.
- Inspect contacts for discoloration, damage, or a contact that does not move as designed.
Fix it in this order
- Reconnect the dock at both ends and verify the outlet with another device.
- Clean the contacts with lightly dampened melamine foam or cloth as iRobot directs.
- Reseat the battery.
- If a contact is damaged/green/copper-colored/stuck, replace/service the damaged robot or base rather than polishing indefinitely.
Evidence to keep
- Dock power result
- Photos of contacts
- Whether dock acknowledges placement
- Charge percentage before/after
Do not make it harder
- Abrasive sanding of contacts
- Assuming dock LED equals healthy charging current
- Forcing stuck contacts
How you know it is fixed
- The robot docks and charge percentage rises normally without Error 4/5.
If the obvious fix does not work
- If the dock acknowledges the robot but charge percentage never rises, continue with battery/robot diagnosis.
- If the dock does not acknowledge the robot at all after alignment and cleaning, the base or contact hardware is the stronger suspect.
If this still isn't resolved
- iRobot support if clean, undamaged contacts still produce low-current errors
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.