Depends on where you are and what you are doing, I suppose. The key thing - as far as I am concerned - is to be able to use the device the way I want and for it to respond adequately to the situation in which I am using it. That said, it is important to pay attention to battery care. Among other things, this involves draining the battery and charging back up to calibrate it once in a while. If you go to the Surface pages on the MS website, you will find what MS recommends is the way to care for the battery. Generally, I follow that, but I use the device the way I want and don't obsess about such things.