v0.4.0 - Real-time battery SOC estimation

Highlights

• Adds a reusable, toolbox-free two-state extended Kalman filter for real-time battery state-of-charge and RC-polarization estimation.
• Uses the same piecewise-linear OCV table for voltage prediction and the local dOCV/dSOC measurement Jacobian.
• Applies a Joseph-form covariance update and supports strictly increasing uniform or irregular measurement timestamps.
• Includes a deterministic one-hour benchmark with a deliberate 20-percentage-point initial SOC bias and repeatable noisy terminal-voltage measurements.

Verified benchmark

• Initial prior SOC error: -0.200
• First posterior SOC error: -0.142
• Final SOC error: +0.0001
• SOC RMSE: 0.0066
• Sustained two-percent settling time: 18 s
• Posterior terminal-voltage RMSE: 1.581 mV

The full MATLAB/Simulink workflow reports All 13 MATLAB and Simulink checks passed. Citation metadata and Markdown links also pass their independent workflows.

Start here

• Battery SOC EKF guide
• Complete changelog

run('examples/battery-soc-ekf/check_battery_soc_ekf.m')
run('examples/battery-soc-ekf/run_battery_soc_ekf.m')

The model remains an educational reference. Replace the illustrative OCV, electrical parameters, and covariance tuning before cell-specific use.