These look more convincing - the Penasamigs were kind of wrinkly.

I also used to buy fake duracells, those worked just as well as the real ones. Penasamigs were literally hollow cardboard tubes.

In fact, I'm pretty sure the fake duracells were real duracells (probably either OEM or factory rejects) that were illegally repackaged; the batteries themselves were indistiguishable from the real thing. Mine were 9v in the second (black and white) packaging shown here, and I'd buy them again.

I've seen repackaged Duracells at various dollar and discount stores. I also assumed they were factory overruns, not necessarily fake. Anyway, I use rechargeable batteries almost exclusively.

They seem to be legit. I really only use batteries for fuzz pedals and the $.50 "heavy duty" carbon batteries actually sound noticeably better in most of the old designs and only need to be changed every year or two.

Rechargables have finally reached the point where they hold a charge and don't take forever to recharge, so I use them pretty exclusively. I got into it after having to change batteries every 1500 pictures with my old camera.

I've noticed that everything I get now that comes with batteries always comes with a brand I've never heard of and will never see again in another product.

I use rechargables for digital stuff but I still have trouble with NiMH losing its charge really quickly in the cold. When I was traveling last spring I got about 20 photos per charge because it was still getting pretty cold at night in the desert; same set of batteries is good for a month or two of regular use at room temperature.

One time I bought a 24-pack of Enercells at a dollar store in NYC, and they worked. For about 10 minutes.