Energy storage system is an Emerging technology
in past few decades. The Energy storage system is an important
technology for Electric Vehicles, Hybrid Electric Vehicles (EV)
and (HVE) and Micro grid system. The Battery Management
System (BMS) is need to be control and monitor the various
parameter of the battery such as SOC , SOH, C-Rate, E-Rate
,Temperature , RVL , EOL and so on. However, the (SOC) State
of Charge is an important estimation for the online control and
BMS monitoring. The SOC is the challenging task when online
control and BMS monitoring. This various technique or methods
available to estimate the SOC and alsoits represents the
Elaboration for various methods of SOC estimation and its
drawback. Past five years, where the tendency of the Estimation
technique has been oriented towards a mixture of probabilistic
techniques and some Artificial Intelligence.