I want this one but your charger needs to be capable of 24v this is gnarly!
Picture two Hyperion 5s packs on a Duo3 charging at 15 amps Each simultaneously! This is overkill for the average enthusiast! Lol! I'm not a big fan of ghetto power supplies, I like to do it right once and be done with it.
http://www.maxamps.com/Power-Supply-24V.htm