Hello,
I am trying to calculate the Li‑Ion battery failure rate using the model from FIDES 2022 in a scenario where the number of charge/discharge cycles per year (NbCD_Annual) is less than 50 per year and where no maintenance is performed.
Based on my understanding, the current model does not provide an adequate estimation of wear‑out behaviour for such low cycling conditions.
As an example, if I calculate λ_Ageing for a Li‑Ion battery with the following parameters:
- Power density: 230 W/kg (NbCD = 1000, OL2 = 20 000)
- Annual charge/discharge cycles: between 1 and 438 (NbCD_Annual)
- Operating time: 8760 hours/year, no maintenance (PrPM = CM), β = 5.0
; 
; 
Then the model returns OL1 ≥ 20 000; CM = 29 151.57; λ_Ageing (wear‑out) = 23 696.66. I obtain the same result both in Excel and in FIDES Lab 1.5.3, regardless of whether NbCD_Annual is 1 or 438:
Could you please advise whether there is a way to obtain a more precise estimation of λ_Ageing for Li‑Ion batteries under low cycling conditions?