But in a message to consumers Apple insisted: "The factors causing the performance issues do not present a safety risk.
"You may continue to use your current battery."
The free battery fix patch can be downloaded from the Apple website, with the group urging all MacBook and MacBook Pro users, as well as customers who purchased extra batteries between February 2006 and April 2007, to run the update software.
Apple also says it will replace the faulty batteries free of charge.
Problems first flagged up by consumers and disclosed by Apple include batteries not being recognised by the laptops, not charging properly and becoming "visibly deformed".
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