Battery pack and method for controlling discharge of secondary cell

A battery pack that supplies power to an electronic device, the electronic device improving instantaneously a processing speed with peak discharge power higher than power in a usual state, the battery pack comprising:

• a battery group in which a plurality of secondary batteries are connected in series;
• a detector that detects a charging and discharging current value flowing in the battery group and a voltage value of the battery group in a time-division manner by switching between the current value and the voltage value using an electronic circuit;
• and
• a controller/operator that performs operation and control using the current value and the voltage value detected by the detector,
• wherein the detector detects current values before and after the voltage value of the battery group is detected, and the controller/operator determines that the voltage value of the battery group is influenced by the peak discharge power when at least one of the current values exceeds a predetermined threshold and the voltage value of the battery group is less than or equal to a predetermined voltage value.