A mathematical approach for representing the discrete events in the cycling studies of lithium-ion batteries as a continuum event has been proposed to generate charge/discharge curves for N number of battery cycles. Simulations of up to 5000 cycles have been performed using this technique using the solid-phase diffusion model. A nonlinear electrochemical engineering model, which describes the galvanostatic charge/open-circuit/discharge processes of a thin-film nickel electrode, has also been investigated to test and validate the computational performance of the continuum representation technique. Finally, the tested technique is implemented for an existing full-order pseudo-two-dimensional lithium-ion battery model that has several coupled and nonlinear partial differential equations in multiple domains. The continuum representation, which is expressed as a function of a dependent variable in time t, works efficiently for several cycles with very minimal model initialization efforts and computation cost. However, it is not ideal for state detection. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3258044] All rights reserved.