About the same weight as 14-16 nimh cells to be precise , so using a pair of packs in parallel negates any weight-savings, though yeah, run time will be something like 1 hour +. Would make more sense to buy 4x 2s 25-35c 5000mah packs, and just swap them over half way through your bash session as the first pair of lipos run out of puff. 'Sensible' isnt in my vocabulary however...