Hybrid or electric vehicles include a traction battery to store and provide motive energy. For effective operation of the traction battery, operating parameters, such as state of charge and battery power limits, may need to be known. The operating parameters can be based on a persistent excitation parameter of the traction battery and a measurement bias of the traction battery that depends on a temporal difference and a temperature difference between parameter measurements of the traction battery. A controller can execute instructions to implement a state estimator configured to output battery state based on a persistent excitation parameter of the traction battery and a measurement bias of the traction battery that depends on at least one of a temporal difference and a temperature difference between parameter measurements of the traction battery, and operate the traction battery according to output of the state estimator.