Charging Smaller Lithium Batteries Gently?

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 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.

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.

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.