For a long time Nook insisted their ereader be recharged off the USB port of a computer. Mighty inconvenient at times. But I do realize that hammering the little guy with lots of current might be detrimental to its life. Down here I would be well and truly "threaded" if the Nook goes belly up. The last time one did I went without for five months.So here comes the question...What kind of power do computer USB ports generate? My earlier post had to do with "N" and "NA" ports on a USB wall wart. For some reason a 50/50 chance I have been connecting the NOOK to the A and my cell phone to the NA ports.But would it not be wise to limit the charge times to say shut off after 12-hours?Also with lithium technology does discharge depth limit the number of usable cycles? I have been recharging the NOOK when I gets down to 50 - 70% remaining capacity. Is this a wasted effort? Like no difference if I allowed the battery to discharge to 10 - 20% remaining?The cellphone stores, an extremely select extremely long way from here want 40 - 50 dollars worth of pesos for a Hwang Ho brand replacement battery for the Samsung, and I am simply out of luck with the NOOK.Added-on question: The USB charging cables seem to "wear out" after several months. That allows them to simply fall out of the device to be charged USB port. Is there such a thing as a better cable to stop this?Thanks for your help. With lead/acid batteries I know my stuff. With Lithium I know enough to ask...

I know that constantly plugging the usb in the port will render the usb jack less likely to connect as the plastic inside wears down or at least that is how I would characterize it because the contacts are not touching all the time. I have found that if I squeeze the outer metal part of the jack so it is a little tighter fit, it works better. I don't know if this is any help but it is what I have to offer.

Hi Mex,From the reading I've done LI doesn't like to be overcharged. It is quite happy to "stand" at 95%. Speed charging may be bad too. USB presents a pretty low charge rate.When I plug my cell phone into a twelve volt cigarette lighter outlet with two female usb ports and use the GPS feature the screen being on causes the phone to discharge over an 8 hour day. DAMHIK.It does slightly better from a USB port on my laptop.It will not discharge when I use the wall wart on either of my inverters (one is MSW and the big one is PSW).I hope this helps.

I have had this same question for my devices. I talked to the verizon folks and have read a small device like an I phone should charge at no more than 1 amp for long battery life. An I pad can take 2 amps because the battery is bigger. A Nook's battery may be about the size of the I Pad. An occasional fast charge won't hurt them and storing them at 60% charge is better than a full charge. I can't remember the science behind it all.

Li-ion batteries prefer to be recharged as much as possible and do not like to be drawn down low. Most USB chargers charge at one of three common maximum charge rates: 500ma, 1a, 2.1a. However, most devices with these batteries have intelligent charging circuits that will stop the charging process when the battery is full, and many/most/all? will slow the charge rate down as the battery nears full. None will allow the device to charge at an unsafe rate; so even if you use a 2.1a charger, your device might only pull 500ma. If you are curious, you can get a USB volt/amp meter on Amazon for $15 or so.

FYI..... if your Nook dies... which it eventually will, you can replace it with a generic Android or Windows tablet, and get the Nook reading app for either one. You can download anything you've purchased from the BN store.I have a Nook Color which is 5 years old. I charge it overnight routinely, using the USB charger that came with it. Battery life seems to be about the same as it was new. The biggest problem is that the end of the charging cable has fallen apart multiple times. I'm on the 3rd cable. At some point the cables will be unavailable and the NookColor will become obsolete. I've already replaced it with an Android tablet.

Charging Smaller Lithium Batteries Gently? | Good Sam Community

JoeTampa
Explorer
Dec 18, 2015
Li-ion batteries prefer to be recharged as much as possible and do not like to be drawn down low.

Most USB chargers charge at one of three common maximum charge rates: 500ma, 1a, 2.1a.

However, most devices with these batteries have intelligent charging circuits that will stop the charging process when the battery is full, and many/most/all? will slow the charge rate down as the battery nears full. None will allow the device to charge at an unsafe rate; so even if you use a 2.1a charger, your device might only pull 500ma.

If you are curious, you can get a USB volt/amp meter on Amazon for $15 or so.
Gjac
Explorer III
Dec 18, 2015
I have had this same question for my devices. I talked to the verizon folks and have read a small device like an I phone should charge at no more than 1 amp for long battery life. An I pad can take 2 amps because the battery is bigger. A Nook's battery may be about the size of the I Pad. An occasional fast charge won't hurt them and storing them at 60% charge is better than a full charge. I can't remember the science behind it all.
pianotuna
Nomad III
Dec 18, 2015
Hi Mex,

From the reading I've done LI doesn't like to be overcharged. It is quite happy to "stand" at 95%. Speed charging may be bad too. USB presents a pretty low charge rate.

When I plug my cell phone into a twelve volt cigarette lighter outlet with two female usb ports and use the GPS feature the screen being on causes the phone to discharge over an 8 hour day. DAMHIK.

It does slightly better from a USB port on my laptop.

It will not discharge when I use the wall wart on either of my inverters (one is MSW and the big one is PSW).

I hope this helps.
bcsdguy
Explorer
Dec 18, 2015
I know that constantly plugging the usb in the port will render the usb jack less likely to connect as the plastic inside wears down or at least that is how I would characterize it because the contacts are not touching all the time. I have found that if I squeeze the outer metal part of the jack so it is a little tighter fit, it works better. I don't know if this is any help but it is what I have to offer.

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