One AA won't do much at all.

Batteries and chargers from HK eBayers have always worked for me, but their lifespan is almost always very short. I had two chargers for my Nikon break from being dropped 6" onto a desk. Batteries often stop holding a charge after a few months. I still got a knock-off Nokia battery (right down to the copied hologram) for my N810 because they're so damned cheap. If I charge often enough, I'll never have to use it.

I'd hate to pay up for a real Nokia battery and then never use it.