Patent ID: 8116997

Claim:
A battery-capacity supervisory control device for supervising a connection between a battery and a load through a power inverter, comprising: a detecting loop which is arranged for electrically connecting between said battery and a power inverter for detecting output current and voltage of said battery; a microprocessor which is electrically connected with said detecting loop for obtaining a first voltage value before said battery electrically discharges, and a second voltage value as well as an output current value of said battery after electrically discharging for a predetermined time unit of said battery, in order to calculate available capacity of said battery, and to calculate available time of said battery under loading according to said available capacity of said battery; and a display unit which is operatively connected with said microprocessor in order to display said available capacity of said battery and said available time of said battery under loading; wherein said microprocessor not only determines an amount of electricity consumed in a unit time by said battery in responsive to said first and second voltage values and said output current value of said battery, but also calculates to obtain accumulated loss of power of said load in a unit time in responsive to said accumulated loss of power of said load in a unit time and efficiency of converting, wherein said available capacity of said battery is taken to be divided by said accumulated loss of power of said load in a unit time to obtain available time of said battery under loading.