Making battery packs

I have some 7 cell packs i bought of ebay a while ago and i want to make them side by side packs. i have the battery bars to do it. At the moment they are stick packs with the 7th cell ontop so you can fit it in a stock maxx, but now i have the flm chassis i want to make them side by side. Do i need shrink wrap? or can i just glue them together side by side without the shrink wrap? and what glue should i use? Thanks :)