The Alaska Center for Energy and Power (ACEP) seeks to address issues related to operation of wind-diesel hybrid systems in remote Alaska communities, and showcase technologies that have potential for reducing fossil fuel consumption and energy costs. One storage solution is the integration of a battery system. Currently, lead acid batteries have insufficient lifetimes to justify their use in such an integrated system. An alternative technology is the flow battery energy storage system (FBESS), which consists of a battery stack with flowing fluids. These batteries have the advantage of allowing additional capacity simply by adding larger storage tanks and additional fluids. ACEP's battery performance testing involves characterization in relation to manufacturer specifications. Since many of these products are either in the development phase or new to the market, the aim is to verify performance and assess suitability for operation amid the challenges unique to Alaska, notably extreme temperatures and isolated wind-diesel hybrid power systems.