I can't objectively measure these batteries with test equipment, but I can tell you that I've gone through a 48 pack since June 22, 2016, and they hold up as well as the Kirkland and Duracells I used previously. I read countless reviews here on different brands after I decided there must be a good alternative to those aforementioned brands, and indeed, I've found it with these solid AC Delcos.
These last as long, maybe longer than Kirklands/Duracells. And, most importantly: THESE AC DELCO BATTERIES DO NOT LEAK. That's why I, and probably you too if you're reading this, got away from those other brands. Most assuredly, in the 15 months since I started using these in headlamps and flashlights, I would have had at least a few leakers from Kirkland or Duracell batteries. I use all sorts of CREE lights for my kids and me plus I lend flashlights to fellow Scouts on camp outs. They get used pretty heavily and I leave the batteries in the lamps until I put fresh ones before the next camp out if they finally start to dim. This is begging for a leak, leaving mostly-drained batteries in a device for months -- but not one has failed me yet.
I just hope I didn't jinx myself for bragging about how good these are. I promise I'll update my review if I get a leaker with these of with the AA batteries I'm about to order.