This one is for those of us modding where a 7.2V pack just won't fit. Wish you ever had a pack that was a different shape? I'll start with a common 7.2V pack. Got it from Radio Shack but it is pretty common. This technique shows the particular shape I needed but you can configure as needed.

Part 1

Step one, use a hobby knife to cut away the heat shrink tubing. You will find that the pack becomes quite flexible. Upon inspection, you will see that the cells have a small strip of Nickle spot welded to either side. This is done because it is easy to solder to. You can use wire cutters to cut the Nickle where needed.