At least 10 - 12 pounds minimum will be fine, however the bigger the cooler, the more ice you'll need to ensure optimal ice retention. We recommend a 2:1 ice-to-can ratio for all our backpack coolers.
The ice retention really depends on how much ice you are adding to the cooler. If you add only a small amount of ice, it is going to melt faster. We recommend a 2:1 ice-to-can ratio for all our bac...