Actually,
Serum's way is best. Because there aren't any nickel strips between the cells, the cells can actually be soldered end to end. This will give a lower resistance than side by side because there aren't any battery bars to add more resistance. A direct connection between electronics will always yield the lowest resistance.
EDIT:
The cells are soldered together using a "hammerhead" soldering iron tip. Here is one:
http://cheapbatterypacks.com/main.as...4635&pgid=misc (scroll down and look for "HAMMER")
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