Good tutorial. I'll just add a couple of things for flat-tops:
1. Save the plastic insulation ring from the positive end of the battery, assuming it's not damaged. You can re-use it. Otherwise, you'll have to get a replacement ring.
2. If you're using a blow-dryer, you'll have to hold the plastic ring down with a finger, until the positive end starts to shrink (so do the positive end first). Otherwise, the ring will blow out of the tube, and you might have to use another wrapper and do it all over again.
Of course it can be rewrapped, you just have to find some shrinkwrap of the right size. You may not be able to find it precut, but may have to cut it to length yourself. Look for shrinkwrap on Ebay, in Vape shops and electronic parts shops.
I picked up 2 meters of clear 16340 wrap for less than $2. I use it to add some width to a few CR123's in order to reduce battery rattle on lights that don't require frequent battery swaps. Works well.
So I have a few keeppower 18650 that the tail springs on my light have eaten away at the negative end of the battery making for not so good contact. I remember seeing replacement brass “I think”disks for this. But can’t remember where can anybody point me in the right direction? Thanks
After much experimentation I found the best way (for me anyway) to re-wrap a battery is to cut out several pieces of heat-shrink using a guillotine and they all end up being the same length with the ends square. I use a proper heat gun and try and stick the battery vertically on a small flat spacer so the heat-shrink drops down lower and covers the spacer. Then I get a consistent overhang of the tubing around the ends of the battery. Careful even application of heat is required so that wrinkles don't develop. I saw a comment earlier about how do you get the side creases out. I take the un-shrunk tube, open it out flat so the creases are in the center of the flats then on a flat surface run a fingernail over the crease to 'iron' it out. This seems to work fine on all the different types of tubing I have tried.