The battery operation time depends on conditions such as: (a) Total mAh inside the Battery for Excellent Backup for Mobile Phone during heavy usage. (b) Completely tested before dispatching. (c) It is a replacement battery with complete mAh. We ask you to use an original company charger to charge your mobile and our battery. Any other charger can affect your battery and mobile drastically. Check if there is any dust in the connector or if any pin is broken or not. Also check for any corrosion in contact and plug. Clean the plug before installing it. Make sure you use ESA safe ----- only check the interface connector to see if there is any dust or not. If there is any dust then clean or replace the interface connector as required. Please drain all the power of the battery for the first 5 times before charging, and then take a full charge. Thus the battery can be reached the optimum effect of using. Please note that its full effect and longevity is only achieved after 3 to 5 complete charge and discharge circles because Li-on battery become stable after few uses.