Apple has determined that, in a limited number of older generation 15-inch MacBook Pro units, the battery may overheat and pose a fire safety risk. Affected units were sold primarily between September 2015 and February 2017 and product eligibility is determined by the product serial number.
Customer safety is always Apple's top priority, and we have voluntarily decided to replace affected batteries, free of charge.
Please visit this link and follow the instructions to see if you are eligible for this program.
