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• Magical Runtime

  theonetruestickman • 07/15/2023 at 18:11 • 1 comment

  A couple days into our trip I had free time and finished assembling everything into the case and started runtime test.
  Observations:

  • Form factor is a little weird due to the cell shape & size.
  • Brightness is plenty to see by in the dark - brighter than I'd like actually, I ended up putting it under the table pointed at the wall.
  • Not quite as bright as a flashlight though

  
  After 72 hours of continuous run I went back to check my math. It turns out I mis-read/mis-remembered the cell capacity and it's 13.3Wh, not 3.7Wh, which means I should have about nine days of runtime with the current ~17mA configuration. I guess it meets original design requirements. 

  Future thoughts:

  • Multiple brightness modes could be useful, at least for nightlight/working light levels
  • It needs better physical design for light modes
    • Nightlight - anti-glare/down-light
    • Table/general - diffusion, also anti-glare
    • Flashlight - no diffusion, able to pick up and hold directionally

  I'm not sure if all of those can be done well at the same time or not but it's percolating.

• Initial Build

  theonetruestickman • 07/14/2023 at 01:51 • 0 comments

  Parts were collected, and bodged together. I did this all the week before going camping for a week - I figured that would be a good test.
  
  

  Initial math told me with a 3.7Wh cell I should get 48hr runtime if I use less than 20mA, so I used a 220ohm resistor. This gives ~17ma at 3.7V nominal for the cell.
  

  
  I whipped up a quick 3d printed clamshell prototype, charged it up, and went on vacation.
  

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