You do not need a special back cover to use this battery This package is specifically designed for the cellphones we list here, if your cellphone is not in the list , then it's not for you.====================================================================== 1)4000mAh Excellent Replacement Li_ion Battery: * Brand: Unbranded/Generic .* High quality Li-Ion battery.* Battery Type: Lithium Ion.* Battery Capacity: 4000mAh . * Voltage: 3.88V. * This battery is internal battery with pipe line,it has an integrated microchip that prevents overcharging and lengthens battery life.* Best Replacement for the original battery with comparable standby and talk time .* Our battery is sent out with little or no power, so please charge it for about 6 - 12 hours before using. * Each battery comes with a special chip to protect your smart phone from over-heating, short-circuit, over charging or over discharging.* Integrated microchip prevents overcharging and lengthens battery life.* When using the battery, please notice that use up all the power of battery for the first three times before charging, and then take a full charge, thus the battery can be reached the optimum effect of using.Please remember that its full performance and longevity is only achieved after 3 to 5 complete charge and discharge cycles.* Replace your existing smart phone battery with a stronger.(The battery operation time depends on conditions .such as: Transmitting power level, Signal (distance between the phone and the base station),Network parameters defined by the operator.)