When I came across http://www.cordlesstoolsbattery.com/, I do not think I can find the battery for my 10 years cordless hammer, but when I search on it, I got a surprise, I find it. Thanks.
It was now after 6 months, the battery is still good.
Tip for consumers: The customer service on it is still very good. If you can not search the right item, just email them, you can get a reply in 24 hours.