I have only had my Nook Color for two years and it is not charging. I have brought it into the store twice and also tried a new cord and adapter, so far, nothing is working. In the store they told me there was nothing they can do. I called nook support and was also told there was nothing they can do. The person I spoke with told me to buy a previously owned nook at a discounted price. I am not happy with the device or the service I have received.
You may want to replace the battery. There are suppliers online for them and installation videos too.
I would suggest watching a couple of the installation videos first before ordering and attempting to replace the "unreplaceable" battery.
B&N never designed the device to be a simple replacement. And since they do not support the NookColor anymore (unless it is under warranty), I would not expect them to be very helpful.