Charging Smaller Lithium Batteries Gently?

[MEXICOWANDERER]

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...

[cleo43]

I have an iPad 2 which I left constantly on its (original) charger. Does it harm the battery life ? The reason is it does not get used much (too heavy) since the day I bought an Android 7" tablet.
In the old days I knew my notebooks' battery went kaput fast if I did that, but battery technology nowadays changes.
I want to add that the iPad stays cool always.

[fj12ryder]

You might check out your USB cables too. There is a company, and I simply cannot remember the name, who was making really bad USB cables.

Is the Nook a tablet or an e-ink reader? If it's just an e-reader the battery should last weeks, not hours.

With the wall wart, I would think the A is 2.1 amp, and the NA 1 amp, due to the newer Apple products being able use the higher pull, and having larger battery packs.

Fred Langa did some tests with the Lithium X batteries and he came to the conclusion that the real enemy of the batteries is heat. According to his tests, heat will dramatically lessen the life of a Li X battery. Something like leaving them on the dash in the sun is really hard on them.

[Gdetrailer]

MEXICOWANDERER wrote:
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...

COMPUTER USB ports (USB speed versions 1-2) ARE limited to 500 ma max PER PORT. When the USB spec was drawn up nearly 20 yrs ago it was never envisioned to provide CHARGING power.

The USB ports on a computer were really designed to power small low power devices like keyboards, mouse, flash drives and some peripherals.

USB version 3 increases the data speed and SOME USB 3 ports are capable of higher current to devices. But do be aware, USB ports although backward compatible are strictly designed for EXTERNAL HARD DRIVES or bootable devices.. SO the OS may not allow more than 500 ma to a device which is not bootable when detected..

As far as devices using Lithium batteries, you should not have any fear of overcharging the battery. The device manufacturer MUST include PROPER battery management for charging and discharging in order to get a Lithium battery manufacturer to agree to supply batteries for the device..

Proper battery management will include over current (charge/discharge), over temp, and auto charge disconnect (device stops charging battery but if device is turned on it will use the power supply to operate instead of battery) when the battery reaches full charge.

Your Nook (and other devices using a USB port for charging)will have been designed to "adapt" to the power supply which is connected to the UBS charge port of the device.

In otherwords, if you connect the Nook to a PC it will only be able to charge at 500 ma (taking forever to charge).. But if you connect it to a separate USB power supply which has 2.4A available the Nook WILL now adapt to what ever max SAFE charging rate the battery is allowed up to 2.4A..

YES, the device while charging at a higher rate will most likely become warm to touch, that is normal..

BURNING HOT to touch (IE pick it up and it is so hot you can't hold it without getting burned) is another matter.

[pianotuna]

Hi Mex,

It sounds as if you have programs running in the background on the Galaxy. GPS location, Hot Spot, Blue Tooth and WIFI are energy hogs, turn them off until you need them. My S3 would run in standby mode (i.e. on and ready to answer) for 5 days. My S4 is even better.

To see what apps are "running" hold down the button at the bottom of the screen for about 3 seconds . To stop the items slide them off the screen to the right.

There is also a way to limit the phone to only run 2 apps at one time--but I'm not familiar with how that is done.

[MEXICOWANDERER]

The Samsung Galaxy 2 phone I have screams OVERCHARGE DISCONNECT! but I suspect the device is monitoring temperarure since this is a summer-only occurance.

The Nook's Glow Light really adds to the battery burden. Takes the useful run time down from say thirty five hours down to ten.

I dang near feel like gluing one of those battery packs thingees onto the NOOK and glue a USB connector wite stub between the two gizmos. Fatter, heavier but maybe (?) Far longer periods between recharges. Is this just wishful thinking or are those recharge battery packs too high of voltage or very limited capacity? I wouldn't mind a bit going 2-weeks between recharges.

The Galaxy2 seems to eat 1% capacity per minute but the discharge percentage speeds up the lower it gets. Glue a danged second battery on that critter? It came to me used so maybe the battery is getting old. I just don't like to be stuck near recharging ports the whole time. Thanks everyone.

[paulcardoza]

Too many hyperbolic answers.... Li-ion batteries are so superior to previous rechargeables that it's almost comical to see the panic here.

Have no fear of plugging it into your new wall plate usb. Li-ion batteries have no memory like nicad batteries did, so whether you recharge frequently or run them all the way down, it won't affect performance.

there are hundreds of millions, if not billions of Li-ion batteries in use every day. If there were issues, the news would be riddled with horror stories.

[rexlion]

IIRC most computer USB ports put out 500 mA.

[Flapper]

Lithium batteries can do all sorts of bad things - like explode, if even slightly mistreated. That said, ALL small devices (tablets, readers, phones, etc.) incorporate voltage regulation, balancing and overcharge protection electronics to prevent bad things. They also monitor voltage and shut themselves down before you can do damage to the battery. So, if you are using the standard USB cord, even in a "high power" wall charger, the internal electronics in the Nook will protect things. And letting it run down until its "dead" won't harm it - the battery is a long way from fully depleted, but the device won't let you drain it any more.
So, when it does die someday, there's little you could have done differently to have postponed the inevitable.
Just don't start cutting wires or opening the case to try and "adapt" it to something it won't normally be able to connect to!

[MrWizard]

my table and phone is charged daily, the wifes tablet twice daily
i have never notice any problems with loose cables

my tablet or phone is likley to get an overnight charge, say 12 hrs

the phone will get less time, but like you i try not to let the phone get too low
but i have run the tablet to 12%, and a couple of time I ran the phone until it shut down, and had too do with out while it recharged

i bought a spare battery and charger for the phone

[coolmom42]

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.

[JoeTampa]

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]

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]

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]

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.