I build them all the time.

Key items needed:
-powerfull soldering iron 40watts min.
-Proper solder.

-Tin each cell(apply solder to each end)
-Tin each battery bar


Get a battery jig its very helfull. Or if you have time install them into your car and drop a dab of shoo-goo between the cells to join the cells. This ensure a perfect fit in your car and when the goo dries it will be simple to solder the cells together.

This guys has a great web site with lots of info. Take a look at his walk through for building packs.
www.balakracing.com/convertsidebyside.htm

Joel Lagace Ottawa, Ontario Canada VISIT: www.rcottawa.com