A battery pack includes a pack body that includes a battery cell and that has an external shape substantially symmetric with respect to the horizontal and vertical axes, viewed from a front face on which terminals are arranged, and a terminal unit on the front face. The terminal unit includes a positive terminal, a negative terminal, a control terminal, and a temperature detection terminal for outputting temperature data. The positive terminal and the negative terminal are arranged on one side with respect to a center line in the width direction of the pack body. The control terminal is arranged symmetrically to the temperature detection terminal with respect to the center line in the width direction of the pack body.