I have two A123 packs in my Boomerang Elan, plugged directly into an AR9100 reciever. Works great 26 flights so far , and I only use 280 mh out of each battery for 3 flights of 10 minutes each, I could probably fly it 10 flights without charging, but I charge after 5-6 flights to be safe. I use the Fromeco Ion Cube to charge, I have two slots of the charger set up for A123's and the other three are for Li-Ion packs.