IEC 62932-2-1:2020 specifies methods of test and requirements for the flow battery system (FBS) and the flow battery energy system (FBES) for the verification of their performances. This document is applicable to FBES or FBS which are designed and used for service in stationary locations (i.e. not generally to be moved from place to place). This document does not cover testing of the system for electromagnetic compatibility (EMC).