The Nook HD+ is the most finicky of any of my devices when it comes to charging. I have multiple car chargers and an AC charger that charge at 2.1a and nada. I have an Anker 5000mAh charger that does 2.1a and nada. I just succumbed to their car kit (thankfully on sale for $15, and I have a $10 gift card), but I have zero solution for an extended trip or keeping it charged in the work bag.
I really do not get why they made it so finicky. You'd think for a company that is playing from behind the 8 ball, they'd make this thing as user friendly as possible.
Someone mentioned it's looking for a specific voltage, and if it doesn't sense it, it doesn't charge. I have a Rocketfish charger made for the Kindle Fire and it charges the HD+ just fine. Scosche and Anker make decent 3rd party chargers. It's frustrating to see them not do the job with the HD+.
I just bought a Nook HD+ and I've been wondering about external batteries. I did a lot of research, and it seemed that the only company making external batteries which mentions any Nook products is Anker, specifically the Astro3E. Based on Crog's comments, I had my doubts, but I contacted Anker by email and they responded quickly, assuring me that if I bought that model battery and it didn't charge my HD+ they'd send me a return label for a full refund.
I got the battery today, charged it up, and then ran it to my HD+ using the Nook cable. It worked! the HD+'s charging light came on amber, and the lock screen read "charging, 60%" (an accurate reading based on the battery indicator). The Astro3E charged my HD+ up to full within 1 to 2 hours and still had close to 75% of its charge remaining.
I should note that the Anker battery did not come with a charger. However, Anker says their battery is compatible with any USB wall charger putting out 5 volts and at least 1.5 amps. I used the Nook wall charger for the Anker battery, and it worked like a charm.
Standard Disclaimer: I don't work for Anker, I don't know anyone who does, and I have no financial interest in the company.
Now that you've had this a week or so, what do you think of it?
Chris-OC I am interested to find out what you think, as well. I have several other Anker external batteries, and think their quality is great. Don't have the one you mentioned, though, and was bummed I couldn't use my current ones for my Nook. I hope you can let us know how this model is working for you,
I couldn't get my HD to charge off my uNu Enerpak, either, so I dug into it a little. After experimentation I found that the Nook HD expects the USB Data+ and Data- wires to be cross-connected or it won't accept the charger even though the voltage is correct. (That's when you get the green light.) If you cross-connect the data lines, then the light will turn orange and the HD will draw charging current. For my HD that's about 1.5A, the HD+ probably draws more, so your battery pack must be able to supply at least 2A as well as have the cross-connected data lines.
I can charge my ND+ from my desktop computer. In this case the data lines are not connected and charging is limited to 500ma. If using another charger and the data lines are connected it will charge at a higher current. I just think the Nook HD+ is very sensitive to the voltage.
I can charge my ND+ from my desktop computer. In this case the data lines are not connected and charging is limited to 500ma.
This appears to be a feature built into the Nook OS. As in, it will show that it's charging slowly when it is plugged into a USB connector that has data (like one on a computer). Otherwise it tends to ignore USB charging ports that do not have the data line termination.
So it's not really so much about voltage, but about what the Nook is looking for in the USB port.
The Anker Astro 3E works well for me.