You'll be better off if you re-think your strategy - you need to secure the packs such that they simply can't move, then you won't need padding. I use 1" wide velcro on the bottom of the lipo and the tray. Walmart sells a 25' roll for about $1/ft. I use at least two additional straps, one at each end and my soft pacs don't move - cartwheels, jumps, crashes, etc - they don't move, I've never damaged one.

You can't pad them adequately, they simply have to be secured so they can not move.


Watch the pac the next few cycles, if its just lightly dented, I doubt you've caused significant damage.