Cordless vacuum shows E8 and will not start or stops immediately, often after storage in a cold or hot area

Safety first: Remove the battery from the vacuum and keep it away from heat sources or open flames.

• Normalize temperature: If the vacuum or battery was in a very cold garage or hot car, bring it indoors and let it sit at room temperature (20–25°C / 68–77°F) for at least 2 hours.
• Check for swelling or damage: Inspect the battery for bulging, cracks, or leaks. If any are present, do not use the battery. Dispose of it according to local e-waste regulations and replace it.
• Try charging at room temperature: Once the battery is at room temperature, connect it to the charger. If E8 clears and charging proceeds normally, the issue was likely temperature-related.
• If E8 appears even at room temperature: The internal temperature sensor or BMS board in the battery is likely faulty. Replace the battery pack with an original Proscenic unit.