Joint Center for Energy Storage Research (JCESR) 1 article published in JoVE Chemistry A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery Wentao Duan*1,2, Rama S. Vemuri*1,3, Dehong Hu3, Zheng Yang1,4, Xiaoliang Wei1,2 1Joint Center for Energy Storage Research (JCESR), 2Energy & Environment Directorate, Pacific Northwest National Laboratory, 3Earth & Biological Systems Directorate, Pacific Northwest National Laboratory, 4Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory We present the protocols for electrochemically evaluating a symmetric non-aqueous organic redox flow battery and for diagnosing its state of charge using FTIR.