<p>Moving from fossil fuel power generation to renewable energy generation brings a number of challenges that must be addressed. Generating energy intermittently is one of the main problems of renewable energy sources, requiring energy storage systems to be able to respond to demand when energy is not being generated. There are many types of energy storage systems. Among them, one of the most interesting in the last decades has been vanadium redox flow batteries (VRFBs) because of their long lifetime and scalability. The performance of VRFBs is affected by many different parameters, including the electrolyte flow rate. This paper presents a performance study of a VRFB battery operating with different charge and discharge currents and different electrolyte flow rates. The experiments were carried out using numerical models that model the mass transfer dynamics, the hydraulic system to calculate pressure losses and the shunt currents of a VRFB.</p>