I’m not familiar with Panasonic BLF19 battery, may I know if the battery already built-in over discharge/ short circuit protection? my previous R&D prosthetics using 18650 battery, which already built-in over discharge, over charge , and over current protection.
Prosthetic hand need to be safe to use, if the BLF19 not included all this, I will suggest to put a fuse or polyswitch ( resetable fuse ) at battery board, and also low voltage detector in arduino to cut off power when battery goes low.
I considered using 18650 but BLF19 and its charger are sold all over the world. We can also easily find substitutes of BLF19 with affordable price.
Further, the battery for consumer electronics is basically safer than individual cells. They got certifications, they’re covered with plastic case and they’re easy to use for all people.
That’s why we decided to use BLF19.