the included battery is rechargable and you can recharge by plugging a USB cable
How is battery?
This is by far the best mouse I've owned. Stylish and precise, feels great in the hand as well. The one thing I have to complain about is battery life. I use this on a daily basis at work and I find myself having to recharge it once a week. It's not a huge complaints because the included battery is rechargable and you can recharge by plugging a USB cable, but most other wireless mice has a considerably longer battery life. That's the only reason I'm giving this a 4 instead of 5 stars.Also, the scroll wheel had a feature that wasn't obvious to me at first when I looked at the product online: there is a small button next to the scroll wheel which switches between normal scrolling found in other mice (where you hear a grinding noise as you scroll) and a smooth super-fast scrolling (with this, if you spin the scroll wheel fast, it just keeps scrolling freely on its own for a good couple of seconds before it stops!) 