During cycles, the battery thickness changes for the three reasons-(i) expansion and contraction of host materials due to lithium intercalation, (ii) electrode volume increase caused by irreversible reaction deposits, and (iii) dead volume and pressure changes within the cell case depending on battery structure and construction. In this study we have identified and quantified those three reasons and related thickness increases employing commercially available thin prismatic lithium ion and polymer cells. (C) 2003 Elsevier Science B.V. All rights reserved.