Compatible Battery For K10

I've had poor experiences with compatible batteries. Can anyone recommend a good, reasonably long life D-L150 repalcement battery for the K10. The genuine Pentax ones are total rip off.

Many thanks

Hi GOM...hehe...I don't have an answer for you, but I'm going to stick this so it stays at the top. I feel that this would benefit other K10 owners if we can get some good answers.
I hate proprietary batteries, but I guess that's the way consumerism works.

hard to find