Robot vacuum says “Charging Error 3” and will not charge or holds almost no charge.

Safety first: Do not attempt to open the battery pack. Dispose of damaged batteries according to local regulations.

Steps to resolve:

• Inspect battery: Remove the battery and check for swelling, leaks, or damage. Do not reuse a damaged battery.
• Install a known-good battery: Replace with a genuine iRobot-compatible battery pack.
• Fully charge: Place the robot on the Home Base and allow it to charge uninterrupted for at least 3 hours.

When to replace parts: If a new, correct battery still triggers Charging Error 3, the robot’s charging circuitry or main board is likely faulty and needs professional service.