Power module and power supply method thereof

A power supply method, adapted to a power module, wherein the power module comprises at least three batteries, a first voltage output terminal, a second voltage output terminal, a third voltage output terminal and a charging/discharging control unit, and supplies power to a computer system, comprising:

• receiving a load signal of the computer system;
• and
• determining a quantity of serially connected batteries based on the load signal, to supply a first voltage, a second voltage, or a third voltage to the computer system, wherein
• the first voltage, the second voltage, and the third voltage correspond to different quantities of batteries,
• the first voltage output terminal, the second voltage output terminal, and the third voltage output terminal correspond to different voltage levels,
• when the charging/discharging control unit is used for charging the batteries, the first output voltage terminal is used as a first voltage input terminal, the second output voltage terminal is used as a second voltage input terminal, the third output voltage termina is used as a third voltage input terminal, and the charging/discharging control unit determines a quantity of serially connected batteries to be charged based on power of the batteries to instruct a charging unit to output a first charging voltage to the first voltage input terminal, a second charging voltage to the second voltage input terminal, or a third charging voltage to the third voltage input terminal, and
• the first charging voltage, the second charging voltage, and the third charging voltage correspond to different quantities of batteries to be charged.