In my world, AA batteries are all about door locks. There are a lot of card-reading door locks that depend on them.<p>Whenever a lock fails, step one or two or three is replace the batteries. That's 4-6 batteries per lock.<p>As a maintenance/security procedure, once every couple of years, every battery in every lock in the entire building is replaced. Doesn't matter if they are dead, weak or brand new. That's hundreds/thousands of batteries.<p>That's a lot of batteries. And Duracell has multiple levels of "pro"/"industrial grade" batteries. We buy them by the case.<p>I'm sure the markup on consumer batteries are huge, but I'd also think the commercial use of double-As must dwarf the consumer market. Smart buy by Warren is my guess.<p>What's needed in this space is a door lock that winds itself much like a "perpetual" watch. Something that takes the mechanical energy used to turn the door handle and turns it into stored energy that can be used to read the card and unbolt the door.<p>And there you go. Make this thing :)