Apple mouse issue

Battery issue and closing down the iMac times.

I have been using the cordless mouse that came with the iMac for a long time and found

battery use is more than I care to think about. Which is fairly quick compare to the battery use of the Keyboard which last a lot lot longer.

Is this just the normal thing that the changeable battery apple mouse battery drain is normal?

Goes though 10% drain every two week but the keyboard hasn't change in that time frame and stayed at 100% even after 3 weeks and counting.

Imac is still under warranty as well to make a mention.

I ended up buying the Apple corded mouse and noticed something else as well - computer shuts down a lot faster compare to before with

varied times of delay in shutting down the Mac that I find rather odd.

your thoughts?