This is a pretty good article on how to build an A123 pack from a Dewalt battery. http://www.rcgroups.com/forums/showthread.php?t=599316 I just buy my cells from BPHobbies instead of disassembling a Dewalt battery.

If all the cells are in series then the capacity is 2300mAh.

Some advantages are no puffing, not easily damaged, can be discharged 100%, and lasts over a 1000 cycles. I use them in my big helicopter and love the batteries.