MODULAR BATTERY SYSTEMS AND BATTERY MODULES THEREOF

A modular battery system and a battery module thereof are provided. The battery module comprises a peripheral sidewall, at least one battery cell and a connector structure. The peripheral sidewall defines a tubular space. The at least one battery cell is disposed in the tubular space. The connector structure is disposed on km edge of the peripheral sidewall and configured to fasten an external module including an open entrance to an external space. The edge defines an opening of the tubular space. When the connector structure fastens the external module, a fluid channel is formed by joining the opening defined by the edge and the open entrance of the external module, and a shape of the fluid channel is defined by the tubular space, a shape of each of the at least one battery cell and the external space.