there are a few ways, you can 1. buy a ready made batter pack in the configuration needed, ie 8 flat pack 8 4x4 pack ect. you can also ( i did this for a pack) buy 8 quality AA Mah rechargable batteries, load them into the tx battery holder and use that way. i bought 20 new in package Duracell 2500 Mah batts on ebay for 32.00 shipped!!!!! sold 8 to my neighbor for 24.00. laod and charge. 3 buy the pieces needed, matched AA Mah batteries, wire, ends, shrink wrap tin strips to connect +s and -s. solder them up as needed. shrink wrap it and charge it and your off
hth
Timmahh