I want some backup batteries for my Panasonic digital cameras. When I look up prices on Kelkoo, Froogle etc I find places like Pixmania selling them around the �40 mark... but other places quoting nearer �10. Can these be the real thing? Some say 'replacement' or 'equivalent' but some just say they're Panasonic batteries, and the photos appear the same as the official ones I've got. Are they? If they're not, are they significantly worse than the real thing, or do Panasonic themselves just overcharge?