State of Charge Estimation for Lithium Polymer Batteries

Lithium Polymer (Li-Po) batteries are commonly used as a rechargeable power
source in mobile systems and remotely controlled. However, the common constraint of
Li-Po batteries is that the battery units must be used within their limits during charging
and discharging period. The inefficient use during charging or discharging will affect the
lifetime and discharge rate of the battery. Therefore, correct state-of-charge (SOC)
estimation of the battery can alert the user about the remaining voltage capacity and the
need for re-charging. Thus, SOC indication helps to protect these batteries from being
overcharged or being discharged beyond its limit.