Provided inside a trolley are: a battery 1； a switchgear 2 arranged in a main path connecting a load 100 to the battery 1； a control circuit 7 controlling the load 100 and connected, parallel to the load 100, to the main path for which connection to the battery 1 is switched by the switchgear 2； a startup switch 4 opened and closed by operation of a key 29 by an operator； and a startup circuit 5 that is connected to the battery 1 and activates the switchgear 2 when the startup switch 4 is in the closing state. Electric power supplied from the battery 1 to the startup circuit 5 is converted by a startup DC-DC converter 3 to a voltage that activates the startup circuit 5. Besides, electric power supplied from the battery 1 to the control circuit 7 is converted by a control DC-DC converter 6 to a voltage that activates the control circuit 7. When the device is in a sleep mode, electric power supply is received from the startup DC-DC converter 3 and a startup circuit connection relay 55 detects input from an operation switch 30 and operates.
