Last week, I tried a very simple proof of concept with a CR1220.

It worked for maybe 20 mins. 

The battery just didn't have enough capacity to power the haptic motor for any length of time. So, I'm going back to the drawing board, and looking at larger LIPO battery (which means by bracelet may be larger than I initially wanted it to be).

Unfortunately, I don't have the tools to test my new design properly. Specifically, I want to track battery performance (current and voltage) over time. I can't seem to find an off-the-shelf tool to do that for me, so I'm building my voltage logger with some leftover Adafruit parts I have on hand.

Specifically, I'm using:

• ESP8266 Feather (note: I prefer the ESP32, but I have 6 ESP8266 feathers un-used in my toolbox)
• TFT Featherwing
• INA219 Featherwing (this I didn't have and had to buy - I'll use this to track the voltage, current, etc)
• a modified-version of a 3D printed feather case
• assorted connectors and clips to easily connect by projects.

I'll update this post later with a link to the voltage logger (I'll create it as a separate project, in case anyone else wants to leverage the code/design).