HONGYU&reg; GT08 Bluetooth Smart Watch with Camera SIM Card Slot and Smart Health Watch Camera for Android Samsung HTC and IOS Apple iphone Smartphone Bracelet Smartwatch-(Red) na na na na To avoid any charging problem, first remove the battery of the watch, and then reinstalle it back, take 5V500-1000 mA charger to charge the watch 2-3 hours, and then try to boot the watch. For more reasons likely to lead to not charge . Also, Please read the instructions manual carefully; *Replace the USB cable and then try to charge the machine; 2. a long time transport, leading to the first charge cannot boot , the customer first time can use the smart phone charger to charge the watch for a long time.