^^^ Pretty much what he said. I just posted the below on RC Groups, so forgive the paste:
[...] the batteries contain their own charge controller. This way they're able to keep stats on each of the cells over the life of the pack, and use factory algorithms for maintaining balance and maximizing life. When you plug an intelligent flight pack into a charger, all you're really doing is giving the internal controller a power supply to do its job.
In light of that, an external controller will likely cause problems and gain nothing. These are made for people to use without any knowledge of LiPo cycling....so you may have to just sit back and enjoy the hands off approach