IEEE 1679.3-2025

This document provides guidance for an objective evaluation of flow batteries by a potential user for any stationary application. This document is to be used in conjunction with IEEE Std 1679™-2020. In a flow battery, the electrolyte is stored in one or two tanks and pumps are utilized to deliver the electrolyte through the cells in order to recharge or discharge the battery. (When two electrolytes are used, they are often referred to as negolyte and posolyte). The outline of IEEE Std 1679-2020 is followed in this document, with tutorial information specific to flow batteries provided as appropriate. Examples of tutorial information include technology descriptions, operating parameters, failure modes, safety information, battery architecture, and qualification and application considerations. This document does not cover batteries that do not employ flowing electrolyte systems. Sizing, installation, maintenance, and testing techniques are beyond the scope of this document except insofar as they may influence the evaluation of a flow battery for its intended application.