Battery capacity prediction device

The utility model provides a battery capacity prediction device comprising a battery, a voltage line, a current line, an electronic load, a current sensor, a first filtering unit, a first amplifying unit, a second filtering unit, a second amplifying unit, a synchronous analog-to-digital converter, and a control and signal processing unit. The battery includes an electromotive force E, an ohmic resistor R1, a polarization resistor R2 and a polarization capacitor C2, wherein the polarization resistor R2 and the polarization capacitor C2 are respectively connected in series with the ohmic resistor R1 and the electromotive force E after being connected in parallel. The battery is connected with the electronic load and discharges electricity to the electronic load under the control of the control and signal processing unit. The control and signal processing unit is connected with the electronic load, samples a discharge current signal of the electronic load and calculates the values of the ohmic resistor R1, the polarization resistor R2 and the polarization capacitor C2 of the battery. Parameters representing the battery can be measured, and then the capacity of the battery is analyzed and predicted. The method is more accurate than a method in which the capacity of a battery is predicated by the use of battery voltage V and impedance Z.