Abstract Recognizing the importance of the cost to the wider adoption of redox flow batteries, it is critical to achieve the higher utilization of electrolytes and thus reduce the required electrolyte volume. Although the effects of the applied current on the battery performance were extensively explored in previous studies, few of them investigated how to dynamically optimize the applied current with varying state-of-charge conditions during the (dis-)charging process. A variable current strategy is proposed in the present study to dynamically vary the applied current density according to the real-time state-of-charge conditions in a vanadium redox flow battery system. Both simulations and experiments are conducted to confirm the feasibility and practicality of the proposed strategy. The results show that the concentration overpotentials and ohmic losses can be reduced at relatively large or low state-of-charge conditions under the proposed strategy, leading to a more than 10% increment in the effective energy capacity at the required power density, compared to the constant current strategy. In addition, the strategy is further improved by incorporating the variable flowrate, which is shown to further enhance the performance of the battery system.