Battery degradation is non-linear, and when it reaches a certain point of degradation it can be become unstable. This has lead to 80% being the traditionally co

Battery degradation is non-linear, and when it reaches a certain point of degradation it can be become unstable. This has lead to 80% being the traditionally considered point for EOL of a Li-Ion pack. However, this is a rule of thumb and the data is evolving with the technology. "When the battery degrades to a certain point, for instance, if a battery can only retain 80% of its initial capacity,9, 10, 11 the battery should be retired to ensure the safety and reliability of the battery-powered systems." Xiaosong Hu, Le Xu, Xianke Lin, Michael Pecht, Battery Lifetime Prognostics, Joule, Volume 4, Issue 2, 2020, https://www.sciencedirect.com/science/article/pii/S2542435119305859 https://www.sciencedirect.com/science/article/pii/S254243511...