Vacuum shows “Err 15”; LED battery icon may flash abnormally and the unit refuses to charge.

Safety first: If the battery feels very hot, do not touch it with bare hands; allow it to cool naturally away from flammable materials.

• Allow cooling or warming: If the vacuum was used heavily, let it sit powered OFF at room temperature for at least 30–60 minutes before charging. If stored in a cold garage, bring it indoors for several hours.
• Check ventilation: Ensure the charging dock is in a well‑ventilated area, not inside a cabinet or under blankets.
• Inspect battery: Remove the battery and check for swelling or deformation. Do not reuse a damaged pack.
• Retry charging: Reinstall the battery and place the vacuum on the charger. If Err 15 clears after temperature normalizes, continue normal use.
• Replace battery: If Err 15 appears even at normal room temperature, the internal temperature sensor in the battery pack may be faulty; replace the battery with a genuine iRobot pack.