My Sony rechargeable battery is half dead, all 4 of them, 2500mAh capacity. Each fully charge will power up 50 to 60 percent of the original power, even after a full discharge and recharge is the same.
I bought the battery one and half years ago for photo shooting, just use it for about 5 times, now it was half dead. I don't use it often, may be that is the main cause of the power reduction problem.
The Sony battery, is not cheap. I get 4 of them with a little bit of discount price of RM110 (USD35.50), it came with a charger.
After waiting for almost 2 months time, the Apple AA rechargeable battery is available in Malaysia! (Together with Apple Magic Trackpad). A package of 6 AA battery and charger, selling for RM99 (USD29.00).
Apple claims that these rechargeable battery is most green among other similar product available on the market. It use least power after the battery fully charged, up to a 10-years lifespan (please refer to Apple website for reference).
It was not stated there but they say this Apple rechargeable battery is actually Sanyo rechargeable battery, 1900mAh capacity. Why it came with 6 pax? 2 for wireless keyboard, 2 for magic mouse and 2 for magic trackpad, just nice!