Puk sensors
Replacing a Puk battery
A standard CR2032 coin cell, about eighteen months of life, and a two-minute job with no tools.
The Puk runs on a CR2032 coin cell — the flat silver battery sold in every supermarket and pharmacy. It lasts around a year and a half, and you replace it yourself.
The swap
- Open the battery compartment.
- Lift the old cell out.
- Drop the new one in with the + side facing up, the way the old one came out.
- Close it.
The Puk wakes as soon as the cell touches its contacts and rejoins your Tali on its own. Nothing needs re-pairing and no history is lost.
Buying cells
Any brand of CR2032 is fine. Buy them somewhere with turnover — coin cells sold loose from a dusty rack are often half-drained before you get them home, which is a frustrating way to spend an afternoon chasing a sensor that was never broken.
Why it lasts so long
A Puk carries no Wi-Fi radio. It measures, whispers the result to your Tali over Bluetooth, and goes back to sleep. That is the whole reason a battery this small lasts this long.