It’s been over two years since AirTag shipped, and if you got one at launch, it’s again time to replace that battery before it dies on you. Here’s how to do it.
The battery is a commonly available CR2032 one.An AirTag battery will last for a bit longer than a year, and your iPhone will warn you when that battery is low. But since you don’t know how good your battery is anymore until you get to that point, that’s potentially a big problem.

