Management device and power supply system

A management device comprising:

• a plurality of power source circuits connected respectively to a plurality of series cell groups each including a plurality of cells connected in series, the plurality of power source circuits each being configured to be able to selectively charge any one of the plurality of cells included in each of the plurality of series cell groups by using a voltage across each of the plurality of series cell groups;
• a plurality of discharge circuits connected respectively to the plurality of series cell groups, the plurality of discharge circuits each being configured to be able to discharge a capacity stored in each of the plurality of series cell groups;
• a voltage detection circuit that detects each of voltages of the plurality of cells included in each of the plurality of series cell groups;
• and
• a controlling circuit that acquires a voltage value of each of the plurality of cells from the voltage detection circuit and controls the plurality of power source circuits and the plurality of discharge circuits,
• wherein the controlling circuit equalizes states of the plurality of cells included in each of the plurality of series cell groups by using the plurality of power source circuits, and equalizes states of the plurality of series cell groups by using the plurality of discharge circuits.