Apple warns of 'deformed' MacBook batteries

Many of Apple's MacBook batteries are failing to work and are "visibly deformed", the company has admitted.

Apple notebooks sold between February 2006 and April 2007 may contain batteries suffering from "performance issues", according to a support document issued by Apple on Friday. These issues include batteries not charging when they are plugged into mains power, not being recognised by the computer and displaying incorrect charge information or being "visibly deformed".

Apple is offering a software update to affected customers. The update should be run on all MacBook and MacBook Pro computers and spare batteries purchased during the affected period. If the update does not work, users are advised to make an appointment with their local Apple retail store or call Apple support because their batteries may be eligible for exchange.

The company is at pains to point out that these issues are not related to last year's recall of 1.8 million Sony-built batteries. In that instance, fears of overheating made the batteries a safety risk, whereas the more recent issues should not require customers to stop using their current batteries.