The last gen iPod nano toured a 30-hour battery life. Also, you don’t need to peg the CPU for rendering audio - this can be accomplished with a very low-power DSP. The lack of radios also offers significant savings when compared to a smart watch, which you forgot needs to be able to receive notifications.
I’ve professionally developed the firmware for several embedded systems and consumer electronics devices with very strict power requirements.
dual_sport_dork@lemmy.world 2 days ago
The 7th gen iPod Nano which you’re referring to (not the 6th gen the commenter above posted, which had a rated 24 hour battery life) had a 200 mAh battery.
A lowly Garmin Forerunner 230 like the one strapped to my wrist right now has a 150 mAh battery and achieves five weeks of battery life with notifications enabled (which I did not “forget”) and the BLE radio twittering away all day, GPS time and position updates, activity tracking, and the screen displaying content all the time. Not 30 hours. 840 hours.
Just acting as a plain watch with the connectivity turned off Garmin claim it’ll last 12 weeks (2016 hours).
I should not have to point out to anyone that it is physically impossible for an iPod to achieve a significantly shorter runtime on a larger battery without consuming more power in the process.
SpaceNoodle@lemmy.world 2 days ago
Now imagine at best halving the physical space for that hall battery by adding a waterproof USB-C port and associated PD electronics - which at that scale would mean significantly more than a 50% reduction in battery life.