We evaluated Li-ion battery deterioration capacity characteristics that reflect the conditions under which mobile phones are actually used. Using the capacity deterioration characteristics of each cycle deterioration and storage deterioration, we show how the deterioration is influenced by the number of charge-discharge cycles and the state of charge and we show the characteristics of cycle deterioration differ from those of storage deterioration. We also show that the lifetime characteristics of a mobile phone battery is typically determined more by storage deterioration than by cycle deterioration within the pattern of the mobile phone. (c) 2004 Elsevier B.V. All rights reserved.