We don't use this device often and when I went to recharge it, it was dead. The green light would light, then turn to amber, then off. I found the original AC to USB adapter and it did the same thing.
On advice from Google, I repeatedly tried disconnecting when it turned amber and after 10 or 20 tries, the amber light stayed on. A half hour later, the Nook booted.
Apparently, there is a protection circuit that prevents a really dead battery from taking a charge except for a brief period of time. Many of those brief periods recharged the battery sufficiently to continue charging.
The Nook HD+ is a pleasant device. Nice big screen and with an update to Nougat 7.1, it is useful. Still no 5Ghz WiFi but the 2.4 works well enough.
If Einstein was wrong about "Insanity is repeating the same mistakes and expecting different results" at least in this instance, he can be forgiven for his early misconceptions about race and ethnicity.