This is teh way I figure width - if your lipo is 140x40x20mm (LxWxH), you'd need shrink at least 60mm wide.

Add the (W + H) of the battery and get something close to that in width. Length is length of the pac - I'm usually generous here, my Hakko heat gun will pull it up as long as I don't get ridiculous with length. Closest for the example appears to be 68mm width.



http://www.batteryspace.com/prod-spe...ink%20wrap.pdf