Cordless SEBO vacuum battery will not charge; charger light stays off or blinks rapidly and vacuum never gains runtime.

Safety first: Unplug the charger before cleaning contacts. Do not use metal tools on live contacts.

• Inspect charger: Check the charger brick and cable for cuts, kinks, or burn marks. If the indicator light never turns on, replace the charger.
• Clean contacts: Wipe the battery and charger contacts with a dry cloth. For stubborn oxidation, gently rub with a clean pencil eraser and wipe away debris.
• Try another outlet: Plug the charger into a different wall socket, avoiding power strips or extension cords.
• Test another battery/charger: If available, test your battery on another SEBO charger, or test another battery on your charger to isolate the faulty component.
• Replace faulty part: If the charger is confirmed good but the battery will not accept charge, replace the battery pack.