Better Energy Storage Technology Act or the BEST Act This bill addresses grid-scale energy storage systems. Specifically, the bill requires the Department of Energy (DOE) to establish a research and development program for energy storage systems, components, and materials across multiple program offices of DOE, including analyzing the need for various types of energy storage to improve electric grid resilience and reliability; develop a five-year strategic plan that identifies research, development, demonstration, and commercial application goals for the program; support the standardized testing and validation of energy storage systems under the program through collaboration with one or more National Laboratories; provide technical assistance for commercial application of energy storage technologies to eligible entities; create a competitive grant program for the demonstration of energy storage systems that use either a single system or aggregations of multiple systems; and establish a research, development, and demonstration program of recycling of energy storage systems containing critical minerals.