Apple has announced a replacement program for its Smart Battery Cases due to a malfunction that prevents them from charging.

The Smart Battery Case extends an iPhone’s battery life by as much as 50%, according to Apple. Many customers, however, have been experiencing problems charging their cases. Some of the defective cases do not charge, or charge intermittently when plugged in. Others fail to charge the iPhone, or charge it intermittently.

Apple has discovered that some cases for the iPhone XS, iPhone XS Max and iPhone XR manufactured between January and October 2019 may be defective, although the company does confirm it is not a safety issue. Apple stores, as well as Apple Authorized Service Providers “will replace eligible battery cases, free of charge.”

While it’s always annoying when a piece of technology malfunctions, at least Apple is replacing the cases for free. A quick trip to the Apple Store and road warriors should be back to enjoying the extended runtime the Smart Battery Case provides.