Have you ever wondered why some batteries drain faster than others? The answer often lies in the tests engineers use to measure their internal components. In a recent study, researchers tried five different ways to charge and discharge an NMC (Nickel-Manganese-Cobalt) battery. They called these methods "operating profiles": C/5 (slow), C/2 (medium), 1C (fast), Pulse (intermittent) and DST (constant discharge). Then they combined these profiles into 31 different groups, running each experiment with an algorithm called Particle Swarm Optimization to find the right values of the battery's hidden parameters. The Single Particle Model (SPM) calculated the battery voltage and compared the results with real data. The researchers evaluated three things: how wrong the calculated voltage was (voltage error), how far the found parameters were from the true values (parameter error) and how much time it took (time cost). The results show that using all five profiles makes the calculated voltage closest to reality. If you only want precise parameter values, the group {C/5, C/2, Pulse, DST} is the best. To save time, the single 1C profile is unbeatable. When you need both voltage and parameter accuracy without losing too much time, the group {C/5, C/2, 1C, DST} wins. These insights help designers choose the right test for each goal, making batteries more efficient and longerβlasting.
The study employed Particle Swarm Optimization (PSO) to identify the parameters of the Single Particle Model (SPM), an approach that mimics the collective behavior of a swarm of particles to efficiently explore the parameter space. Each operating profile was applied to controlled charge/discharge cycles, generating highβresolution voltage and current data. Voltage error was quantified as the RMS difference between simulated and measured voltage, while parameter error was measured as the relative deviation from known reference values. Time cost was calculated in seconds of computation for each combination. The analysis revealed that using multiple profiles reduces voltage error by covering a broader range of the battery's dynamic behavior. However, adding too many profiles increases optimization time, creating a tradeβoff. The set {C/5, C/2, Pulse, DST} provided the best balance between parameter accuracy and computational speed, while the single 1C profile offered the shortest execution time at the expense of voltage precision. The optimal combination {C/5, C/2, 1C, DST} balanced all three objectives, making it ideal for practical applications requiring both realistic voltage and rapid parameter estimation. These findings offer practical guidance for designers and researchers selecting operating profiles for NMC battery testing, optimizing both accuracy and efficiency.
