Learn how to change a SmartTag's battery.
- Locate the small slit on the bottom edge of the tag.
- Use your fingernails or a pry opening tool to separate the two halves of the tag.
- Remove the old battery and replace it with a new CR2032 lithium coin battery.
( https://www.staples.com/duracell-2032-lithium-battery-3v-2-pack-durdl2032b2pk/product_384338 )