Robot vacuum displays E12 and may say 'Low battery, cannot start' even after charging.

Safety first: Remove the robot from the dock and turn it OFF before inspecting the battery area.

• Verify full charge: Place the robot on the dock and ensure the charging indicator is on. Allow it to charge uninterrupted for at least 4 hours.
• Check for heat: After charging, feel the underside near the battery compartment. It should be warm at most, not hot. Excessive heat suggests a battery or charging fault.
• Inspect battery contacts: If accessible, open the battery compartment and ensure the battery pack is firmly connected. Clean any visible corrosion on contacts with a dry cloth.
• Run a short test: Start a cleaning cycle and observe how long the robot runs before E12 appears. If it stops within a few minutes, the battery is likely worn out.
• Replace battery: Install a new, original Philips-compatible lithium-ion battery pack. Follow the user manual for correct installation and disposal of the old pack.
• Persistent E12 after new battery: If the error remains, the charging circuit or battery sensing circuit on the main PCB may be defective and requires professional repair.