Symptoms of affected batteries may include non-recognition of the battery, causing an "X" to appear in the battery icon in the Finder menu bar; failed attempts to charge the battery when the computer is plugged into AC power; exhibition of a low charge capacity/runtime when using a fully charged battery with a battery cycle count of less than 300; and/or visibly deformed battery packs. The company said customers who, after installing the battery update, experience any of the listed symptoms can make a reservation to bring the computer with its battery to a local Apple Retail Store or contact an Apple Authorized Service Provider. Apple will then determine whether the battery is eligible for replacement and, if so, will replace the battery free of charge -- even if the MacBook or MacBook Pro is already out of warranty. Apple also noted that the program extends repair coverage on the battery for up to two years from the date of purchase of the computer for MacBook and MacBook Pro systems with Intel Core Duo processors.