Battery Monitoring Device, Battery Monitoring Method, Battery Pack and Electric Vehicle

A battery monitoring apparatus for a battery assembly having a housing and a plurality of battery cells which is received in the housing is provided herein. The battery monitoring apparatus includes a first sensor to detect an internal temperature of the housing; a second sensor to detect an internal pressure of the housing; a third sensor to detect an internal gas of the housing; a power circuit to generate an operating voltage using a direct current power of the battery assembly; and a controller to change the first sensor, the second sensor and the third sensor from an idle state to a wake-up state using the operating voltage. The controller monitors an internal abnormality of the battery assembly based on a detection value collected from each sensor in the wake-up state.