What are you all using to charge your packs?

I am attempting to use my Novak Millenium Pro to charge my receiver packs (Orion 1200 NIMH) but it only charges for about 2 mins before peaking. I assume I am getting false peaks since the packs were only cycled once. Since I am new to nitro, I wanted to get an opinion from you more experience users on whether or not this was a false peak or if it really does only take a few mins to charge.

Thanks!