How to calculate the operation time of one battery?

  When you are buying laptops or digital cameras, its original statement, the battery would normally be used for reference, this is how to calculated? With machine power consumption (power consumption) and the battery capacity is related very much. To maintain a notebook computer/camera operations, many parts needed to complete the drive, such as: CPU computing, the hard drive motor rotation read data access, display the current situation…. etc. These have to rely on battery power supply to operate, and these component is the source of power, the overall increase in the total power consumption, which is the laptop's power consumption, the unit: Wh (kilowatt-hours), on behalf of the number of watts per hour consumption. "watts (W) "Power unit, the product of voltage and current (W = V * I), the voltage to maintain the operation of laptop basic working voltage, current operation depends on the situation, and there are different power consumption, such as open DVD and speakers high power consumption, low-standby power consumption, so the whole, the consumption machine is not fixed, but a low power consumption of high status.

  To imagine a battery is a kettle which is filled with the Water, its capacity is 5000 mAh, If the machinery of electricity consumption is 1000mAh/Per hour, the discharge rate will be released, about five hours on battery power End was released, the machine is 1000 mA power consumption, so when you laptop power consumption is 30 Wh, and your battery specification are 14.4 V, 3600mAh, your battery about Operation time is: 14.4 V * 3.6Ah / 30Wh = 1.728 hours. Therefore, when you buy one battery, that theSpecification are the 14.4 V, 4000mAh, the Operation time is about 1.92 hours