A typical cellphone battery has 2800mAh capacity. It is an obvious processing design that allow cellphone to operate in various power conservative modes. Typically, in idle mode it consume lowest power, in receiving mode little higher, while during a call it consume maximum amount of power ignoring fact of much power consumption of current generation multimedia browsing. Consider above cellphone use 1mA in idle mode, 6mA in wakeup receive mode, and during an active call, it consumes 100mA. During a typical day, it remain 20 Hrs in idle mode, 3.5 Hrs in wake-up receiving mode, and half an hours in active call per day. Calculate battery consumption in each mode and collective battery life