A motor device includes an electric motor operated when supplied with power from a rechargeable battery, a voltage detection unit that detects voltage of the rechargeable battery, a determination unit that performs an abnormality determination based on a comparison of the voltage of the rechargeable battery, which is detected by the voltage detection unit, and a determination value, a control unit that controls the operation of the electric motor in accordance with the determination result of the determination unit, and a temperature detection unit that detects the usage environment temperature. The determination unit changes the determination value in accordance with the temperature detected by the temperature detection unit and performs the abnormality determination based on the changed determination value.