Capacity is reduced to 80% name plate
Maybe an issue on my end understanding your terminology.
80% SOC? Don’t think anyone is talking about SOC, more of 80% nameplate capacity after so many years and cycles.How have you been seeing LiFePO4 fail?
My experience is when they are down below 80% of original SOC, you can no longer use their rated discharge current, and they do “fall off a cliff” in a similar fashion to other lithium chemistry.
Maybe an issue on my end understanding your terminology.