The undesirable stresses and deformations during a high-speed crash can cause a short circuit or sudden fire in the battery packs, which represents a significant safety concern for vehicles. In this paper, computer-aided simulations are conducted to provide a supplemental and economic approach to evaluate the crashworthiness of a battery-pack enclosure. First, a nonlinear dynamic finite element model of a battery-pack enclosure is established and validated using the modal test. The crush and crash simulations, based on the governing equations and explicit FE code, LS-DYNA, are performed according to the test standard. Second, three high-strength steel materials are used in the validated finite-element model to perform a crashworthiness simulation with respect to robustness and lightweight design. The results show how both materials and thickness affect the crashworthiness of an automotive battery-pack enclosure. Finally, the weight of the battery-pack enclosure is reduced, while the crashworthiness is improved as well.