The nook comes with a Lithium Ion battery. These batteries are notorious for being picky. You need to make sure that you 'Conditioned' the battery. This means that you had to charge it up full before you EVER used it, then kill it till it turns off on you. Then charge it ALL THE WAY BACK UP, kill it and charge it all the way about 6 times, and you will have a 'conditioned' battery. It should last WAY longer. I had the same issues until about the 5th or 6th time.
Hope that helps some of those who are having issues with battery life
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