Several commonly used representations of power densities and their shortcomings for describing the high-power, short-pulse regime are discussed. The Specific Power Profile (SPP) is presented as an informative and well-defined power density representation. The power densities of Mn-based and Go-based Li-ion (commercially available MOLICEL), nickel cadmium, and nickel metal hydride cells are compared using the SPP; (C) 1999 Elsevier Science S.A. All rights reserved.