1. A method for managing a battery in a vehicle, wherein the vehicle includes a battery management controller including a processor and a computer-readable medium containing computer readable and executable instructions, the method comprising: in response to detecting a predetermined state in the vehicle: sensing, with at least one sensor electrically coupled to the battery, a voltage and a current of the battery; executing, in the battery management controller, an instruction to cause the battery management controller to: determine a solid-state diffusion voltage effect employing a solid-state diffusion effects model based upon the sensed voltage of the battery, determine an observed output by subtracting the solid-state diffusion voltage effect from the sensed voltage of the battery, determine double-layer voltage and circuit parameter estimates and an associated covariance based upon the observed output employing an adaptive estimation technique, determine a Kalman gain based upon the double-layer voltage and circuit parameter estimates and the associated covariance, and simultaneously calculate a modeled output of terminal voltage based upon the double-layer voltage and the circuit parameter estimates, sense, with the at least one sensor electrically coupled to the battery, a voltage and a current of the battery, determine an output model error based upon the sensed voltage of the battery, update the double-layer voltage and the circuit parameter estimates based upon the Kalman gain and the output model error, determine an open-circuit voltage of the battery based upon the double-layer voltage, and determine a state of charge for the battery based upon the open-circuit voltage; and managing the power output of the battery using the state of charge for the battery.