Without charging, it can be used normally. Click.... in the upper right corner of the APP Xiaomi Sports Click on my device to check the power level, and generally charge it at 15%.
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2. A function to detect heart rate during aerobic exercise, maintaining a good heart rate can better reduce fat and improve cardiorespiratory capacity. In the photoelectric heart rate sensor light version bracelet, it can detect and prompt the heart rate during exercise in real time, so that you can scientifically adjust the exercise state and continuously and efficiently consume fat. With the running function of Xiaomi Sports app, monitor your movement track, pace, heart rate, and manage the exercise state of every moment.