Cordless vacuum powers on but shuts off within a few seconds, battery LEDs flash briefly

Safety first: Use only the original Medion charger. Do not attempt to open the battery pack; Li-Ion cells can be hazardous.

• Fully recharge: Remove the battery and place it on the charger or dock. Allow a full charge cycle (typically 3–5 hours). Confirm that the charge indicator on the charger and/or battery shows full charge before testing again.
• Clean contacts: Inspect the metal contacts on both the battery and the vacuum handle. Clean with a dry cloth. If there is light oxidation, gently rub with a pencil eraser and wipe clean.
• Test runtime: After full charge, run the vacuum on low power. If it still shuts off within seconds or a minute, the battery cells may be worn out.
• Try another battery (if available): If you have a second Medion battery of the same series, test with it. If the second battery works normally, replace the original battery pack.
• Persistent issue with multiple batteries: If several batteries show the same symptom, the main control PCB may be misreading voltage and should be inspected or replaced by a technician.