Robot vacuum reports E8 and returns to the dock or shuts down.

Safety first: Turn OFF the robot before handling the battery.

• Charge fully: Place the robot on the charging dock and ensure the charging indicator lights. Allow at least 4–6 hours of uninterrupted charging.
• Check dock contacts: Clean the charging contacts on both the robot and dock with a dry cloth. Ensure the dock is on a hard, flat surface and the power adapter is firmly plugged in.
• Inspect battery connection: If comfortable, remove the battery cover (usually on the underside) and verify the battery connector is fully seated in the robot's battery socket.
• Test runtime: After full charge, start a cleaning cycle. If the robot quickly shows E8 again, the battery is likely worn out.
• Replace battery: Install a compatible Ultenic lithium-ion battery pack following the user manual. Dispose of the old battery according to local regulations.