Vanadium flow cell

A flow cell system that utilizes a vanadium chemistry is provided. The flow cell system includes a stack, electrolyte heat exchangers, and a controller executing a state machine. A stack for a flow cell system having an end plate structure comprises a conducting plate and a gasket frame including fluid manifolds. An electrolyte heat exchanger including flow field media; and heat transfer sheets separating the flow field media, and wherein electrolyte and a heat exchange fluid can be flowed through the electrolyte heat exchanger. A controller according to the present invention can include an initialization state; a charge state; a discharge state; a float state; a hibernate state; and a shutdown state.