Yes, you should "form" new NiMh packs at 10/c charge rate or .45 amps on 4500's and "once a month" or so is what I do to "balance" them.

Im really sorry guys, but 10/c I mean im on overload right now! I have no Idea what this stuff means. I just buy packs run em and well, they normaly run fine for me. I just want to make sure im not hurting my batts