Project Log

A project log for Smartwatch 10 Years Ultra-Long Battery Life

Smartwatch wearable, ultra-long life measured in years, no need to recharge.

valentineVALENTINE 01/22/2024 at 01:160 Comments

Haven't updated the log in a while, due to being really busy with the case and the powerplant.

I did a full redesign of the case, will post a new log entry when I get it machined. Designing a case and manufacturing it was a major effort, hopefully this time it will work, this is revision four. The R2 and R3 were really nice but sadly they could not be manufactured. Details later.

Powerplant: also some setbacks. The manufacturer could not properly SMD the design, I'm in a process of re-making it, it will take a week. Meanwhile, I was able to literally carve out (as in with a PCB mini-saw) the power portion of the design and test it.

Picture attached. I managed to read through the fifty pages of documentation for that IC and I'm getting it to the point where it's testable. There are moments I don't fully understand, but will clean up along the way.

Powerplant notes.

1. Connect EN to GND for gen mode. Connect to High for ship mode. Probably reed contact.

2. Connect vout-en to batt-ok. This will set the cold-start automatically vout-en to disable to charge the battery without powering the main circuit load, then exit cold start and enable the vout once the battery is charged to pre-set level and switch to battery + solar unless the battery drops and disable the circuit. I hope I'm doing it right.

3. For some reason the resistors I chose using the provided spreadsheet resulted in 1 volt under for both the charge and voltage out levels. This needs to be investigated, as the spreadsheet might be off or wrong or I got something incorrect during component and PCB design. It's easy to fix by experimentally tweaking the resistors however I don't feel comfortable tweaking without understanding why it works/doesn't work as designed and documented.

Pic under of the setup.

Another major milestone achieved!