A power-supplying device includes a terminal, a rechargeable battery, a first shutdown circuit, and a second shutdown circuit. The terminal is configured to be connected to a power tool. The rechargeable battery is configured to output electrical power to the power tool via the terminal. The first shutdown circuit is positioned at a plus side of the rechargeable battery, the first shutdown circuit being configured to shutdown output of the rechargeable battery. The second shutdown circuit is positioned at a minus side of the rechargeable battery. The second shutdown circuit is configured to shutdown output of the rechargeable battery.