Q: Can I use alkaline AA batteries?
A: Not until recently. You may now with the Classic 3, and Emergency purchased at Costco.
Like with any electronic products out there, we have made improvements to our own! The Classic 3, and the Emergency that is now available at Costco, has our newest generation of lamp circuitry. With with circuitry, you can get 50L of purified water with a set of alkaline batteries.
If you did not purchase your Emergency at Costco, then you have a previous generation circuit, and alkaline batteries just won't be of much use --sorry.
Previous units had a circuit that requires a little more power, and alkaline batteries just aren't up for it. You may get a few doses from alkaline, or none at all, but using alkaline batteries won't hurt the SteriPEN.