Cordless Shark vacuum will not power on; battery icon flashes once then unit shuts off

Safety first: Turn the power switch OFF and remove the battery pack from the vacuum before inspecting. Do not attempt to open the battery pack case.

• 1. Verify correct battery and seating: Confirm you are using a genuine Shark battery compatible with your model (e.g., IZ, IF, IX series). Slide the battery fully into the handle or base until it clicks. If it feels loose or does not latch, remove and reinsert several times.
• 2. Clean battery contacts: Inspect the metal contacts on both the battery and the vacuum handle/base. If you see dust or light corrosion, gently wipe with a dry microfiber cloth. For stubborn oxidation, lightly rub with a pencil eraser, then wipe clean. Do not use liquids.
• 3. Fully charge the battery: Place the battery on the Shark charger or dock. Ensure the charger LED comes on. Allow it to charge for at least 3–4 hours until the indicator shows full. If the charger LED flashes an error or never shows charging, the battery or charger may be faulty.
• 4. Test with and without accessories: Install the battery and try powering the vacuum with no floor nozzle or tools attached. If it powers on without load but shuts off when the floor head is attached, the battery may be weak or the motorized floor nozzle may be overloading it.
• 5. Try a known‑good battery if available: If you have a second Shark battery, test it. If the vacuum works normally with another battery, the original battery pack is likely defective and should be replaced.
• 6. Replace battery if protection persists: If E1 continues after full charging and contact cleaning, the internal battery management circuit may be tripping. Replace the battery pack with a genuine Shark replacement. If a new battery does not resolve the issue, the vacuum main control board may be faulty and professional service is recommended.