Replacing the 'Non-Replaceable' Battery in the Tile Slim
September 27th 2025
I replaced the battery in my Tile Slim! It uses a little tiny pouch cell (Ultralife CP114951 3.1v 380mAh).
Be careful, this is going into scary lithium battery territory. I shaved the plastic from the edges of the Tile Slim until I could peel the plastic shell apart; if I were to do it again, I think that I would sand the edges using some 80 or 120 grit sandpaper. The pouch cell inside is protected by a thin sheet 0.0015″ (0.0381mm) of stainless-steel top and bottom that’s glued in.
After you get into the package, you’ll need to trim off a bit of the rubber around the pouch cell terminals. Trim the terminals as close to the edge of the pouch cell as possible without cutting the pouch cell, while also not shorting your scissors across the terminals!
The pouch cell plus the stainless-steel plus the glue is about 0.0580″ (1.48mm). I wanted to stick close to that but figured going over a bit was ok. With a bit of measuring I figured out I could just fit five CR2016 0.787×0.0629″ (20×1.6mm) batteries in parallel in the case in a “X” configuration.
So, I got out the battery welder and cut some thin nickel strips and started welding. I applied some little strips of Kapton tape to make sure nothing shorted.
I had to add some little extensions to the tabs on the Tile board and then welded the batteries onto the tile board. Finally, a bit of packing tape closes the case back up! I could glue it back together but seems like a pain to undo in a couple years when the batteries need to be replaced again.
