Hi JERIN M JACOB, 1 battery drain: Is the battery drain problem appearing in use or sleep mode? To monitor the battery usage, please go to Settings>>Battery>>More>>Battery usage, and stop or reinstall the high battery usage apps. These are our suggestions to improve the battery drain problem: https://www.asus.com/IN/support/FAQ/1041741 These are our tips to maintain a healthy battery using habit: https://www.asus.com/in/support/FAQ/1009546 If your phone is over one year of use, you may go to service center to check the battery health (life cycle remain), and check if replacing a new battery is needed. 2 cannot use low brightness in night Could you describe in more details? 3 in google photo cannot use to view in mx player. its is slow. so times it hang Do you mean photos taken on this phone cannot be viewed in MX player? Please try reinstalling this app. If it still appears, please tell us the app version. Does this appear to every photo? 4 google file manager is slow to move data Please try clearing cache & data of this app. If the problem still appears, please tell us the app version and show us a short video. 5 ringing volume ,message tune ,alarm have decreasr the sound Do you mean the volume has become lower? Or do you mean sound quality? What's your volume level? Is it lower compared to Android Pie or which version?