Secondary battery charging and discharging device, power storage system employing secondary battery, secondary battery charging and discharging method, and non-transitory computer-readable medium on which secondary battery charging and discharging program is stored

Provided are a secondary battery charging and discharging device, a power storage system employing a secondary battery, a secondary battery charging and discharging method, and a secondary battery charging and discharging program which minimize reductions in electric power efficiency arising from switching losses resulting from pulse charging and discharging, and with which capacity is maximized. The secondary battery charging and discharging device according to the present invention performs pulsed charging, in which charging and pauses in charging are repeated alternately, or pulsed discharging in which discharging and pauses in discharging are repeated alternately, and is provided with: a switch means for performing pulsed charging or pulsed discharging while turning on and off with a prescribed pulse frequency; and a control means for controlling the turning on and off of the switch means; and which performs pulsed charging or pulsed discharging with a pulse frequency corresponding to the number of charging and discharging cycles of the secondary battery.