ive got the same batteries but only 9 c per pack, i was going to put in 4 packs
but if you have enough power with 3 then i might save the weight and not put the 4th in.
I havent had time to make it anyway !. Ive the cellpro 10s aswell seems really good, funny
how at the end of charge the cells are still cool im used to charging the nicads untill nice and toastie !