Comment by Dylan16807
3 hours ago
> Designers have a choice in lithium-ion though. 18650 is is pretty large cell but there's 14500 which is AA sized or 10440 which is AAA sized. They make versions with the usual battery "nub" rather than the flat faces for spot welding, and built-in protection circuitry to prevent over-discharging. You probably would want to use ones of a different size than normal 1.5v cells though. A personal favorite of mine is RCR123A/16340.
But other than 18650 you can't expect to find a lot of devices using any particular size.
We should strive for a couple blessed sizes that a lot of devices will stick with, where all cells include a nub and protection circuitry.
The form factor I'd like to see standardized would be a flat pack like the Nokia phone battery.
Not saying the cylinder doesn't have it's place, but so many of my devices would like a flat pack.
If that happened, it'd have the added benefit of being able to standardized a bms protocol for the packs. Hard to have control pins with a cylinder.
And if you were super clever, you'd make those packs stackable so they could be charged and discharged together.