Need New Batteries

Since I record all of my law classes, it is not a surprise I go through a lot of batteries. I like to have several extras with me, because there have been a number of times that I have run out of juice during a class. Not only does my recorder start beeping, but I lose part of the lecture. And anymore, I am very dependant on being able to hear that info again. I recently read a post that talks about the advantages of rechargable batteries, and how after your initial investment, they are almost free. I guess it would be better for the environment too. Worth looking into.