[maCCer]

if i using my AC adpter should i insert my battery as well?is that would reduce the life of battery?
give me some suggesions about how to use the battery efficiantly?

[wataru]

I think Apple recommends that you leave the battery in all the time. But I read an article that cited experiments on lithium ion batteries in which they found that the optimum storage conditions are about 50% charge and low temperatures. Keeping the battery in all the time would result in 100% charge and higher temperatures. This means that the maximum capacity decreases more quickly with time.

That said, I don't bother taking my battery out. It's too much of a hassle. And what about when you need that 100% charge? You don't want to have to charge it up in advance.