I learned to solder for TI-purposes too! Not for battery but to build the 2.5mm-jack-to-serial connector cable (I was too cheap to buy an official one, but successfully wired together the 2-3 resistors and diodes necessary to make the cable work. It was not pretty, but it worked!)
Same here! I initially had the cable fit with scotch tape and then later soldered to make it work properly. Also first trip to an electronics store, was terrifying to enter a specialist shop with close to no knowledge
