lifetime of lithium coin batteries

Lithium Coin-Cell Batteries: Predicting an Application Lifetime

Abstract: This application note discusses various contributors to battery capacity consumption in a battery-backed application, and how to predict battery lifetime in a system. A designer should be able to use this application note to determine the battery requirements for his system. Maxim builds a large number of products that incorporate lithium coin-cell batteries to provide nonvolatile (NV) memory or real-time clock (RTC) functionality in the absence of system power. The typical specification for these products has been to provide a 10-year battery lifetime in the absence of system power. Because of end-application uncertainties, the lifetime prediction is conservative.End users should evaluate the anticipated lifetime in their specific application, especially for applications that exceed typical commercial environments or that need to reach lifetimes beyond 10 years. An understanding of the reliability model is also beneficial for users opting to purchase discrete battery controllers and combine them with a battery, rather than purchasing the module product containing the controller and battery. This article gives the reader an overview of the major factors affecting the lifetime of an integrated circuit (IC) that can be powered by either the system power or a lithium battery for a backup supply.