This document specifies the general requirements, evaluation indicators and calculation methods, test requirements and methods, Reliability judgment, evaluation results, etc. for the Reliability evaluation of all-vanadium flow battery systems. The scope of application includes the evaluation of all types of all-vanadium flow battery systems for indoor or outdoor use. The document cites a series of normative documents, including counting sampling inspection procedures, all-vanadium flow battery terminology, general technical conditions, system testing methods, and safety requirements. The terms and definitions section defines concepts such as Reliability and Failure. The general requirements include Reliability evaluation indicators and methods. The evaluation methods use sampling tests to conduct corresponding tests and calculate the obtained indicators.