Battery will not charge, charger LED flashes red or E5 appears on vacuum display when docked

Safety first: Disconnect the charger from the wall outlet before inspecting the charger or battery contacts. Do not attempt to open the battery pack or charger.

• Step 1 – Check ambient temperature: Ensure charging is done at room temperature (about 10–30°C). If the battery is hot from recent use, let it cool for at least 30–60 minutes before charging.
• Step 2 – Inspect charger and dock: Look for visible damage, cracks, or burn marks on the charger plug, cable, and docking station. If damaged, stop using it immediately.
• Step 3 – Clean contacts: Wipe the metal contacts on the battery and charger/dock with a dry cloth. Make sure there is no dust, grease, or corrosion.
• Step 4 – Try a different outlet: Plug the charger into another wall socket without an extension cord or power strip to rule out supply issues.
• Step 5 – Observe charger LED behavior: Insert the battery into the charger and note the LED pattern. Compare it with the LED chart in your Bomann manual. If the LED continues to flash an error pattern, the battery’s internal temperature sensor or BMS may be faulty.
• Step 6 – Test with another battery or charger (if available): If you have access to another compatible Bomann battery or charger, cross-test to identify whether the fault lies in the battery or charger.

Replace the defective component with a genuine Bomann battery pack or charger. If E5 persists with new parts, have the vacuum’s charging circuitry inspected by a technician.