A basic unit of lithium-ion battery, including: at least two series-connected lithium-ion cells; at least one lithium-ion cell for balance; controllable switches with the same number as the lithium-ion cells; a drive module for the controllable switches; a voltage detection module for detecting a voltage at two ends of the lithium-ion cells; and a controller. The lithium-ion cell for balance is connected in parallel to the lithium-ion cells. The controllable switches control the turn on/off of the connection in parallel between the lithium-ion cell for balance and each of the lithium-ion cells independently. The drive module for the controllable switches and the voltage detection module are connected to the controller. A battery pack including the basic unit of lithium-ion battery and a method for real-time charge/discharge equalizing of the basic unit of lithium-ion battery are also provided.