Method and apparatus for measuring remaining coulomb of electrical energy storage device

An electronic device comprising:

• a rechargeable electrical energy storage device;
• a measuring apparatus for measuring a remaining coulomb of the rechargeable electrical energy storage device, the measuring apparatus comprising:
• a storing module for storing data on relations between voltage and charge of the rechargeable electrical energy storage device;
• a measuring module for measuring an initial charged coulomb of the rechargeable electrical energy storage device based on the data;
• and
• a processing module for calculating a charged coulomb and a discharged coulomb, calculating the remaining coulomb based on the charged coulomb or the discharged coulomb and the initial charged coulomb, and updating the data with the remaining coulomb.

A measuring method for measuring remaining coulomb of a rechargeable electrical energy storage device, the method comprising steps of:

• measuring a first voltage;
• compensating the first voltage with a first voltage compensation;
• identifying the initial charged coulomb according to the first voltage;
• taking the integral of a current to calculate a value;
• determining that the electrical energy storage device is in the charging state or the discharging state;
• and
• calculating the remaining coulomb by subtracting the value from the initial charged coulomb of the electrical energy storage device before discharging.