This is the amount of insulation to remove allowing it to pass through the barrel connector; it is rubberised, but not very compliant. There are exposed cores after the case if screwed on. Heatshrink required to cover the gap.
Routing on the sole
Joint on to the heater
6 x 100R 1/2W resistors, carefully soldered onto stranded wire. Solid wire has historically hardened and failed very quickly
4/12/19 Both 0V wires failed where they pass through each insole. Used a longer piece of stranded wire to solder between 2 resistors in case the solder had wicked and the wire work hardened.
Battery pack is an old Dell 3s2p pack
1/12/24 3s BAK N18650CL-29 2.9Ah in heatshrink with protection. https://bestpiles.fr/ Much lighter!
