The approach used for calculating the confidence intervals is based on the normal approximation method, leveraging the Central Limit Theorem (CLT) for independent and identically distributed (i.i.d.) random variables. According to the CLT, the cumulative sum of a large number of i.i.d. random variables with finite mean 𝜇 𝑡 * and variance (𝜎 𝑡 * ) 2 approximates a normal distribution, regardless of the original distribution of the variables . This approach allows for an effective evaluation of the cumulative loss over time and its associated confidence intervals, providing valuable insights into the potential variability and uncertainty in the battery capacity estimation process. To begin with, the cumulative loss up to period 𝑇 is computed as the sum of the periodic losses as below: