Mi band 2 brightness fix - Mi Band 2 - Xiaomi MIUI Official ForumA1 answer: if you didn't recharge Ur band for a while means this problem will occur . I also faced this issue. I didn't use my mi band 2 for 6months I didn't put charge as well. due that whole battery drained . Due to that battery health may effected due band under sleep mode after reaching cut of voltage . after charging your band RTC, Bluetooth and sensor will take more power that time battery can't provide that much power due to…