♫Do You Want to Build a Battery Pack?♫ (For My Heated Pants)

Here’s the humble two cell battery pack which came with my heated pants. Woefully inadequate it would turn out, and not only because of the paltry number of cells. To see what’s what, and exactly what all can be done to fix the abysmally low run time of this pack, we’ll have to crack that sumbitch open: