I meant bottom in that you have lost the ability to draw the cells down fully, but they likely still charge up to the correct voltage. Not sure what your warranty terms are but if it's still in warranty it seems like something that should be covered. I don't know if they ever noted some specific cap...
Current draw from cells is usually in terms of the cell capacity versus the hours it takes to discharge. So a 1C draw on a 15Ah cell would be 15A for an hour. Generally the C ratings are very close within the same chemistry and form factor. But even if they differ here they would have to be *extreme...
The pack stops discharging when the lowest cell hits the lower voltage limit and stops charging when the highest cell hits the upper voltage limit. So if one cell is really bad, it can and will keep you from fully discharging the pack. When it's "empty", what is the total pack voltage? If ...