POWER SUPPLY APPARATUS AND ELECTRICITY STORAGE DEVICE

A power supply apparatus includes a latch type first relay inserted between a system power supply and a load, where the latch type first relay includes a switch, a tripping coil configured to open the switch, and a closing coil configured to close the switch, an electricity storage system including a charging and discharging unit inserted between a secondary battery and the load, a non-latch type second relay including a contact and an operating coil configured to open and close the contact, where the operating coil is connected between the electricity storage system and the load, and a control circuit connected to the first relay via the contact of the second relay.