The objective of this recommended practice (RP) is to describe test methods and recommended types of tests to use in evaluating battery degradation. Laboratory-based degradation testing is an effective and independent way to compare the degradation profiles of battery cells across different chemistries and testing variables, such as charging rates and temperatures. Using standardized processes, testing can be performed at any laboratory (within or outside DNV’s own laboratories) and the test results will be compatible across these laboratories so that more conclusive findings can be obtained from the resulting data.
EV designers and potential investors in BESS projects will better understand the need for these types of tests, what the test results indicate about cell life performance, the risks associated with certain battery types, and how to mitigate these risks. Test method standardization and transparency will foster better understanding and dialogue amongst various stakeholders.
This recommended practice focuses on battery cell lifetime performance, and more specifically on how charging, discharging, the environment, and calendar time affect battery state of health (SOH). Additional factors important to battery lifetime performance – but not addressed in this recommended practice – include efficiency, maximum capacity, maximum current, energy density, safety, and many others. Furthermore, batteries are one of many ways to store energy; a separate recommended practice, DNV-RP-0043 covers a broad range of energy storage technologies, not only batteries.