The present invention discloses a battery pack which can be used for an electric vehicle, an Uninterrupted Power Supply (UPS), and a power supply for a smart grid and which can be easily manufactured and repaired and which is capable of improving productivity, the span of life, and performance, and a battery management system including the battery pack.The battery pack of the present invention comprises a casing in which a reception space is provided and battery modules coupled to the casing at regular intervals by fastening members so that the battery modules can be easily dismantled from the casing. Each of the battery modules includes a tray, a battery cell provided in the tray, a cell charger provided in the tray and configured to charge the battery cell, a cell controller provided in the tray and configured to control the cell charger, a heating mat coupled to the battery cell, and a temperature sensor provided in the tray and configured to sense a temperature of the battery cell.