The proliferation and prevalence of lithium ion batteries has produced a surge in research into electrochemical
cell models and the identification of specific unknown cell parameters. Accordingly, optimization methods have
become an area of intense investigation for their inherent ability to determine model parameter values which best
fit to observed data. With the ability to calculate lithium ion cell properties in real time, Battery Management
Systems (BMS) would exhibit significant improvements in decision making for prolonging batteries’ life span
and increasing efficient charging/discharging. The paper analyses the use of Nelder-Mead Simplex algorithm for
estimating three age-dependent parameters of a electrochemical cell model. Results indicate accurate parameter identification for simulation and experimental environments. With real time voltage measurements, applications such as electric vehicles and large power grid batteries would greatly benefit from the use of Nelder-Mead Simplex mentioned throughout this paper.