Apple is acknowledging a problem with a small number of iPhone 5 units.

Some of the phones have faulty batteries that have very short battery life and need to be charged more frequently.

The affected devices were sold between September 2012 and January 2013.

The tech giant is replacing batteries for free in Canada on Aug. 29. It’s already available in the United States and China.

If you have an iPhone 5, click here to input your phone’s serial number to see if you are eligible for a battery replacement.