The present disclosure provides a flow battery module for improving energy efficiency of flow battery during dynamic load conditions. The flow battery module comprises a plurality of stacks connected in any or a combination of parallel and series. One or more pumps are configured to circulate electrolyte to the stack where ion exchange between the electrolyte occurs and a current is generated. A series of switches are configured between the flow battery and an external load or source. Based on the load or charging power stacks can be electrically and fluidically isolated thereby decreasing parasitic power consumption and self-discharge current, and as a result improving energy efficiency.