[afv011]

Battery drain is caused by the CPU not sleeping, and in turn this is caused by some app holding onto a wakelock.

It might be possible to just remove the app that is holding onto the wakelock, though there is a chance that doing so will render the nook unusable (could start crashing and require a factory reset). You need to find out first what app or apps are holding onto that wakelock, and to do so you need to install an app like Better Battery Stats , which requires root so you can install the app.

Once you know what app(s) are draining your device, you can remove them (which again, requires you to be rooted). Instead of just removing them, make a copy so you can put them back if the nook stops working. All this is untested, so you'll be pretty much on your own.

Edit: another possibility, once you figure out the apps causing the drain, is to disable those apps, rather than removing them.