The batteries themselves are great ... on par with the likes of other name brand alkaline batteries. But the real selling point here is being able to buy these high quality batteries in bulk, at a more than reasonable price, and in nice, low-profile packaging that's easy to store. When you have kids in the house, batteries go fast and not only is it inconvenient to buy them in packs of 4 or 8 batteries, but it also gets expensive!

After about 2 1/2 years the remaining batteries in my package all leaked from the ground side. This was in a cool environment.
Do not leave these in devices that are rarely used as they will leak over time and destroy the device.

The batteries are okay and the price is right, but the packaging in a clamshell plastic is really hard to use. The AA size, on the other hand, is packaged better in a more user-friendly boxlike rectangular plastic container - go figure. No one likes clamshell plastic that requires a box cutter to open, only to find that it is nearly impossible to keep the remaining loose batteries in the sharp plastic packaging as you use a few at a time. I'd give the AA size 4 stars, but look for a different brand in the AAA size, or just bite the bullet and get some battery holder boxes so I don't rip up my hands trying to use the original container.

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.

Powerful Lasted longer than Rayovac, Vivitar, Sony and Sunbeam. 10.$/48 count came out the cheapest . I'll always trust AC Delco batteries
to be the best buy among batteries.7/20/15 2nd order came at same price . This is really the best deal there is, and AC Delco is a strong brand battery. I tested DO it Hardware and Walgreens and Harbor Freight generic alkaline batteries along the way and AC Delco really stays the longest above the 1.40 V measure. That;s what I consider a battery to be able to still run a motorized toy at full performance. Anything below 1.30v is practically dead for my purpose but it still works for clocks and thermometers. Staying high-powered longer and being at the most inexpensive level is what a best-buy battery is to me.BTW I use three kinds of testers. One's digital, the two are rough but reliable green/red meters with rough graduations.