I got an idea.......
1. Get a toilet tissue roll (used up of course) slice it down the middle.
2. Slide the cells as if you would do a flashlight, end to end.
3. Tighten the tissue roll as tight as you can and glue in place. Cut off any excess material.
4. Shoo Goo the edges of the newly formed stick pack to keep the batteries from sliding out from either end, but not to cover the ends so you can't solder the leads on.
Viola!!! you got yourself a 2 cell pack!