Not normal unless you've used it a lot since the the night of 1/16.
Mine now seems to be "in line" with my expectations. I charged it the morning of 1/9 and I've probably been averaging 2hrs a day or reading roughly, since then. I just checked and I am at 69% battery life. Supposing it doesn't claim to need a recharge early, that seems to be on track for about a month of battery life at roughly 90-120 minutes of reading a day. I've pretty much plowed through all of a 720 page book (2nd smallest font size) in that time and I'll likely be able to manage another large book before I am getting down to around 20% charge when I plan to recharge it again (probably in about another 2 weeks).
That would be roughly 5 "average" size 300-400 or so page books on a charge which seems to be the "standard" for how long a charge should last.
So at least for me, not that I have throughly tested it, recharging it completly and then immediately rebooting it when I unplug it from the charge seems to work. Maybe there was simply some learning of the battery voltage by the nook that did it, but rebooting costs me little to do after each full charge, even if it is maybe the ebook version of blowing in to the NES cartridge and even if it isn't actually "fixing" anything, and that the nook "fixed" itself.
PS I must note as I am feeling embaressed about my slow reading, but these days with a not quite 4yr old and not quite 2yr old (4 in 2 weeks and 2 in 2 months) I get interupted a lot, so my roughly 2hrs a day of reading is including the entire time I am attempting to read, even if I am maybe only getting in 10 pages in a half hour because I have to keep putting it down to "address a situation". Other times I can plow through 20-30 pages in that time because I don't constantly get distracted.
PPS Despite my wife's suggestion that I return it, I haven't done it because I don't even have the gift recipte (though I doubt they'd stop me from doing a warranty exchange since I can't imagine they can't pull up the SN in their system to see when it was purchased), so I don't want to have to go through that rigamoral. On top of that, I have too much of a tinkerer mentality. I feel like, rightly or wrongly...usually wrongly ;D, that I should/can get something to work right if I give it awhile. I have a hard time admitting defeat.