if you made a series or parallel adapter sure.
edit:
after actually looking at the product on DX:
Would you look at that, already set up to charge multiple packs at once. That is pretty nice.
edit2:
mistercrash: Does this have a storage charge/discharge option? (found answer, yes.)
edit3: I see that you can manually set what voltage you want it to charge/discharge to, cool.
Check out the end of this video, made me laugh.