Try Here They seem competitive enough. Basically though, you get what you pay for. The batteries for my camera (SSP)is just under £100, but they go on forever (3500 plus shots per charge). Compatibles average less than half that.
Thank you for your comments, it just shows you that some bumf stretches the truth just to sell a battery.
I keep searching as its interesting and found lower mA and claiming to be compatible with the FZ40.