In this project, I used FNN to predict the SOC of Li-ion Battary. I first started with the data processed (Normalized, Resampled, Noise Canceled) by other researchers, and with many different algorithms (RNN, FNN, SVM) and structures. After getting a satisfying result, I moved on to the raw data. The way to find the proper data processing algorithm was hard, but the finally worked. Big thank to Phillip J. Kollmeyer. He's Researches and dataset helped me a lot on this project.