Hello Sanya Gode,
here is a document listing the difference between our unscented and extended kalman filters: https://www.mathworks.com/help/control/ug/extended-and-unscented-kalman-filter-algorithms-for-online-state-estimation.html
if you aren't aware, here is an example using kalman filters for battery control: https://www.mathworks.com/help/control/examples/nonlinear-state-estimation-of-a-degrading-battery-system.html
As to the best choice of filter, that will depend on your particular needs and implementation. Hopefully this helps you design some experiments to learn more about the trade space of different filter implementaitons.
Regards,
Joel
