Patent ID: 7714531
Filing Date: 2010-05-11
Classification: H01M,H02J,Y02E

Abstract:
1. A power system comprising: an electrochemical device; a load device; a power generator; and a charge/discharge controller of said electrochemical device, said electrochemical device comprising a positive electrode, a negative electrode, and a liquid electrolyte or a solid electrolyte, said electrochemical device having a charge/discharge curve that has at least one step, a given step of said at least one step having an inflection point, a voltage corresponding to the inflection point or a point adjacent to the inflection point being set as a threshold value, the inflection point existing greater than 0% and less than 100% of a remaining capacity, said charge/discharge controller being configured to control charge/discharge of said electrochemical device, and said power system further comprises a comparator that compares the voltage of said electrochemical device with said threshold value, wherein based on an output of said comparator, said charge/discharge controller causes said electrochemical device to be charged whenever the voltage is lower than said threshold value and causes said electrochemical device to be discharged whenever the voltage is higher than said threshold value so that the voltage of said electrochemical device approaches said threshold value; wherein, when the voltage equals to the threshold value, said charge/discharge controller selects charging if the electrochemical device is being charged upon the output of the comparison result, and select discharging if the electrochemical device is being discharged upon the output of the comparison result.