Recently someone bought some Apple AirTags to look at. Apparently they both stopped working after replacing the battery a few days earlier.
Did both AirTags just decide to die at the same time?
My first clue was that they both decided to die when the battery was replaced.
Were the batteries defective?
In fact, the reason the AirTags have stopped working is because of a safety feature that some manufacturers add to their lithium button cells to prevent them from being eaten and swallowed by children.
The problem: security coatings
Button cells may seem harmless enough, but if ingested they can cause serious health problems.including permanent injury and death (a more graphic description of the injuries can be found) here)–in a very short time. They are dangerous even when discharged, so care must be taken throughout the battery’s life cycle.
To discourage babies and toddlers from putting them in their mouths, some makers apply a coating of an extremely bitter compound called Bitrex to the button cell.
And trust me, this stuff is incredibly bitter (yes, I’ve tried it, so you don’t have to).
But the problem is that this coating can be problematic when the button cell is used in some devices.
And one of those devices is Apple’s AirTags. Apple even mentions it in its battery replacement instructions.
You could buy batteries without the bitter coating on them, but given the danger that lithium button cells are, I wouldn’t do this if there’s a chance kids could get their hands on them.
Alternatively, you can remove the coating. But again, the coating does an important job of protecting young children, so I’m very reluctant to remove it all.
The solution for AirTags that stop working after a battery change
My solution was to remove some of it, or just enough Bitrex for the battery contact to touch the metal of the coin cell.
You don’t need to delete a big patch for the AirTag. Just enough for a small contact.
I use an alcohol swab – a lens cleaning swab or injection swab will do the job – to remove a small amount of the coating. No cotton swabs? A pencil eraser does the job too – just don’t pick anything that you’re going to put in your mouth afterwards!
I find that cleaning about a quarter of the coin cell is enough for the battery to make contact, while simultaneously retaining enough of the bitter compound to discourage ingestion.
Then it’s a matter of testing the battery.
You’ll know when the battery is making good contact with the AirTag because it plays a tune.
For other devices, it’s a similar process to make sure the contacts align with the cleaned part of the battery.
As for protecting kids around button cells, here’s what to do:
- Buy quality brands — these are more likely to be built to higher standards and use safety features.
- Keep batteries in their original packaging until needed.
- Keep them out of sight.
- Remove only a small portion of the bitter layer and only do so as needed.
- If devices have safety features on the battery compartment, such as screws or tabs, be sure to replace them.
- Safely dispose of used button cells.