I’m looking to replace the battery in my Sandisk clip+ with a Supercapacitor.
My thoughts so far:
Original Battery with 290mAh @ 3.7V nominal Voltage. ==> 1.073 Wh
-Provides up to 15h of playback.
Replacement ~250F Capacitor @ 2.7V ((0.5CV^2)/3600) ==> 0.2531 Wh
-Theoretically 3:45h of playback.
Since the Voltage range of a LiPo battery will go from 4.2V fully charged to 3.0V empty I would guess it is safe to run the mp3 player at 3V and minimize conversion loss.
So I need a step-up converter ideally from 0V to 3V.
Simple enough a step-down converter from ~5V to 2.7V.
I guess it should be current-limited to ~500mAh not short out a USB port.
What are your thoughts on this? Did I miss anything?