Vacuum does not start and shows E4 or a red battery LED blinking in a specific pattern after a drop or impact.

Safety first: If the vacuum was dropped and the housing is cracked or the battery is swollen, do not attempt to charge it. Move it to a non‑flammable surface and contact a professional.

• Step 1 – Visual inspection: Check the housing around the battery compartment for cracks or deformation. If the pack is removable, take it out and inspect for swelling or leakage. Do not puncture or crush the pack.
• Step 2 – Reseat battery: If the pack is removable, reinstall it firmly to ensure good contact. Sometimes a shock can loosen the connector.
• Step 3 – Attempt controlled charge: Connect the charger and observe. If the charger LED blinks error or the vacuum immediately shows E4, disconnect.
• Step 4 – Internal check (advanced): If you are experienced and the pack is not swollen, open the housing and inspect the battery harness and BMS board for broken solder joints or loose connectors. Repairing the BMS is specialist work; usually the entire pack is replaced.
• Step 5 – Replace pack: Persistent E4 after impact almost always indicates internal cell or BMS damage. Replace the complete Clatronic battery pack assembly.