All LEDs on the battery flash together when placed on the charger; vacuum will not run.

Safety first: Immediately unplug the charger from the mains. Do not continue charging a battery that shows a fault pattern. Do not puncture or open the pack.

Steps to try:

• Allow to cool: If the battery is warm, let it cool at room temperature for at least 1 hour, away from flammable materials.
• Re‑test once: After cooling, reconnect the charger and observe. If all LEDs flash again, disconnect immediately.
• Inspect for damage: Check the battery casing for cracks, swelling, or signs of impact. Do not use a damaged pack.
• Dispose and replace: Arrange safe recycling of the faulty battery according to local regulations and purchase a genuine Gtech replacement. Do not attempt repair.