Cordless vacuum shows E8 or a continuous red light; the unit will not start, and the battery will not charge fully.

Safety first: Remove the battery from the vacuum and keep it away from flammable materials. Do not attempt to open the battery pack.

Steps:

• Attempt a normal charge: Place the battery on the original Hoover charger and leave it for the full recommended time. Observe the charger LED for any error indications (rapid flashing, no light).
• Check for physical damage: Inspect the battery casing for cracks, swelling, or leakage. If any are present, do not use the battery; dispose of it at a proper battery recycling facility.
• Try a different outlet and charger (if available): Rule out a faulty charger or mains supply.

If E8 persists: The internal cells or BMS are defective. The pack is unsafe or unusable and must be replaced with a genuine Hoover battery pack. Do not attempt DIY cell replacement.