Transport and kinetic parameters of lithium-ion batteries are estimated using a first-principles electrochemical engineering model based on porous electrode theory (1, 2). A full-order model reformulated using advanced mathematical techniques (3, 4) was used for the simulations. Since batteries and other power sources are used in hybrid environments, with devices with time constants less than a second (like a super capacitor or an induction motor), parameter estimation algorithms were developed with high computational efficiency. As a complement to approaches to mathematically model capacity fade that require detailed understanding of each mechanism (5), capacity fade was accurately and efficiently predicted for future cycles by extrapolating the change in effective transport and kinetic parameters with cycle number (N), for a battery under controlled experimental conditions. Parameter estimation using mathematical reformulation (4) was more efficient and robust than full-order models based on the traditional finite difference approach.