Terminals, terminal systems, charging/discharging methods for the terminals, charging/discharging methods for the terminal systems, and discharging methods are disclosed. The terminal is coupled to a second terminal including a second switching unit, a second charging unit and a second battery unit. The second charging unit is coupled to the second battery unit. The terminal includes a first switching unit and a first battery unit. The first switching unit is coupled to each of the second switching unit and the first battery unit. The first switching unit is configured to receive a control instruction or a control signal, and to switch to the second switching unit based on the control instruction or the control signal so as to supply power to the second terminal with the first battery unit, or switch to the second charging unit based on the control instruction or the control signal so as to charge the second battery unit with the first battery unit. Thus, the battery of the terminal can be used to charge the battery of the second terminal or used directly as a second battery for supplying power to the second terminal. This improves user convenience and usability of the terminals.