1. Fully charge the device before first time use because battery maybe run out after long time keeping.
2. There is overheating protection system installed on the device, it will heat for around 1 to 2 minutes and when the tempature is too hot, it will turn off automatically. Under this circumstances, you need to wait until it cools down and then restart it by hand.
Caution: The device will turn off automatically after around 1 minute for safe, please turn on again by hand.