N. Tonawanda, NY
A123's preceded Lipos, they historically could not release current quickly, but I have not built a pack to try them. I routinely use Lithium ion batteries for my starter batteries and to power the RX/servos. I make my own packs using heavy gage wire and balance connectors. They are inexpensive and built better than what is commercially available. IMR has a great selection, there are different chemistries to select from depending on the properties desired.Tom
CAUTION - my posts are based on my experiences, yours may be different.