Here's how to test a CR2032 battery to see if it's good

You won't need expensive equipment or invest much time.

By Husain Parvez Oct. 24, 2026 11:00 am EST OlegD/Shutterstock Add Engadget on Google: Google Discover

Your car key fob suddenly needs several presses to unlock the door. Your AirTag stops responding when you try to locate it. Before blaming either gadget, it's worth checking the battery inside. One common type is the CR2032, a 3V lithium coin cell also used in Samsung's SmartTag2 and some smart home sensors. Depending on the device and how often it's used, one can last way over a year.