What upgrade have you done from the included drone kit? Having pulled the trigger on a bigger drone that I will need to charge not only the very expensive quad batteries but also the transmitter and camera batteries. The Hitek x2 seems to be a very good option to both charge and discharge for storage pretty much any battery. About $100
I haven't used it a whole lot, but I love this thing....bought one and it was so easy to use. http://www.hobbyking.com/hobbyking/store/__49420__X100_AC_DC_100W_Touch_Screen_Charger_US_Plug_.html Looks like it's not available - but similar models probably are. The Hitek looks nice too...but for $50 with the touch screen I'm really happy with that iMax.
