A high-fidelity battery model capable of accurately predicting real-time battery behavior for various operating conditions is crucial for the design and operation of battery-powered systems. Based upon a prior work of the authors, this paper proposes an enhanced hybrid battery model to provide accurate predictions for the runtime behaviors of rechargeable electrochemical battery cells under various ambient temperatures and chargedischarge current conditions. The proposed battery model is validated by simulation and experimental studies for lithium-ion battery cells in various current and temperature conditions. The proposed battery model is computationally effective for design, simulation, condition monitoring, and power management of various battery systems.