Costco Kirkland Batteries vs Duracell

Just wondering if anyone has any experience with both of these batteries.

I'm running battery life tests on my different flashlight mods (2AA cell type).

I was using Kirkland (Costco generic) for all my comparison runs that I'm thinking of putting on my web site.

In this way you can see whether efficiency, more light, less light etc... compare against each other to determine the best tradeoffs relative to run time.

I was rather shocked that my assumption would be most major MFGs of Alkaline should do better if not significantly better than the generic brand.

So, I ran a set of Duracells (AA) through my flashlight and the power (light) out of my MAX1674 flashlight started out lower than all other batteries. It sagged and continued that way running a measly 30 minutes. The Kirkland on the other hand ran a good 90 minutes before dropping off like a rock.

I've got some energizers that I guess I'll have to try those out since this is made me very curious.

Anyone else have any similar experiences?

Others have posted that the extended absence of Kirkland batteries for a while reflected Costco's insistence that their private label batteries must be first rate. Costco apparently waited until they were able to contract for good product at the price they wanted to pay.

Consumer Reports tests battery brands from time to time and they always conclude that the generic brands are as good as the name brands. I think most of the generic brands are just relabeled batteries from the same makers.

- Russ

Thanks for all the info.

I have always viewed Duracell as being near the top for storage energy among Alkaline batteries. Either I have a bad batch of batteries or Duracell quality has changed.