Touch Charge time?

azazel1024 · 01-30-2012, 10:30 AM

So what is the charge time like for most people from computer and wall adapter? I haven't charged directly off my computer, at least not from empty, but BN claims 3 1/2hrs. They also seem to claim the same amount in 1 or 2 places about the wall adapter. However, I checked my nook wall adapter, which isn't labeled with its power specs, and it churns out 5.6w from the wall, so I assume it is a 5v 1amp adapter (running about 90% conversion efficiency from 120v mains).

I'd assume with twice the power of a regular computer .5amp USB port, the charge time would be something roughly half that off a computer port.

So if ~3 1/2hrs from a computer, roughly 2hrs from a wall adapter that can manage 1amp.

Does that sound about right? I am still working on the wonky battery issues I am having with my Nook ST, and just trying to get a feel for what a properly working one should manage from a wall adapter. My most recent charge took somewhere around 1:45hrs from the wall adapter and it was hooked up to my computer first for about 10-15 minutes transfering some books and a few new wall papers. That at least sounds like that should be roughly a full charge from zero (it refused to power on any more the battery was so depleted).

afv011 · 01-30-2012, 11:46 AM

That sounds about right. I only charge from the wall charger, and it never takes more than 2 hours.

RAH · 01-31-2012, 07:55 AM

Same for me - with the wall charger, always about 2 hours from about 25% to 100%.

As you know, from another thread, I also have trouble with the battery in my Touch. I wonder if this might be caused by the more rapid charging using the wall charger. In other words, I wonder if I used the computer to charge from 25% to 100% if the battery might be better behaved. I have never tried it; guess I should, huh!

azazel1024 · 01-31-2012, 09:58 AM

Yeah I don't have a solid idea yet how mine will behave in either scenario, but I did see about a 2% battery drain over 30hrs after a wall charge, with just a little bit of use in there (maybe 5-10 minutes). I then hooked it up to my computer after those ~30hrs to transfer a couple of other books and just top off the charge, which took about 10 minutes hooked up to the computer before it wouldn't charge further.

I am at 97% charge now after around an hour and a half or so of reading time and 36hrs. Though I have noticed the battery reading seems pretty temperature sensitive with just a few degrees F temperature difference leading to at least a handful of percent difference in battery reading (at least when partially discharged).

For now though, either in full wall charge or topping off on my computer, I am going to "assume" it is charging and working fine until it proves completely otherwise. I will keep rebooting right after a full charge...just in case that is what is keeping it from fast draining.

I can certainly see how, between how temperature sensitive the reading is, that a computer hookup/low amp USB hookup could result in the battery actually charging a bit more than it would off of a wall charger. The faster charging of the wall charger would lead to a slightly higher battery temperature which would likely cause the nook to stop charging sooner as the voltage reading on the battery is going to be higher for a lower state of actual capacitance in the battery.

That said, honestly I doubt the real difference is more than a few dozen milliwatt hours of extra charge getting squeezed in at the lower amperage charging rate (maybe 1-2%).

It does make me feel better that the overall charge time on the wall adapter is roughly correct to get from about 0 charge to a full charge and that my nook probably wasn't actually shutting off and refusing to reboot with anything remaining in the tanks.

RAH · 01-31-2012, 10:43 AM

I have a related question. If I tethered the Touch to my computer via USB, I can transfer files to and from it, etc. It also charges. My question is - if I use the Windows tray icon to disconnect the Nook, will it still charge? In other words, I leave it connected to the USB port, but I have already told Windows to disconnect the Nook device and it has. At that point, the device is no longer shown on the computer, but it is still physically connected to the USB port. Does it still charge?

If it does still charge, this seems to me to be the safest way to charge via the computer, instead of leaving it connected and still active as a device on the computer.

azazel1024 · 01-31-2012, 11:13 AM

Yes, it continues to charge over the USB port even if you "eject" the nook from the systems tray.

RAH · 01-31-2012, 04:28 PM

Thanks for the info! Next time it needs a charge (it's at 65% right now), I'm going to charge it the whole way with the computer and see how it behaves aftetward.

Tinderbox (UK) · 01-31-2012, 04:40 PM

How many mah is the included touch usb charger, mine did not come with one, I am in the UK, so the US charger would need an adaptor anyway, so it`s not missed, usb chargers are cheap to buy anyway.

I will take a guess at 700mah

John.

Timur · 01-31-2012, 08:23 PM

Quote:

Originally Posted by Tinderbox (UK)

How many mah is the included touch usb charger, mine did not come with one, I am in the UK, so the US charger would need an adaptor anyway, so it`s not missed, usb chargers are cheap to buy anyway.

I will take a guess at 700mah

John.

Nook touch charger is rated at 0.85A. I had to use an USB microscope to read that tiny script.

FYI, mAh(milliampere-hour, a unit of electric charge) is used to express battery capacity, adapters/chargers are rated by their amperage.

azazel1024 · 02-01-2012, 11:42 AM

Mine appears to be rated at 1amp, as my kill-a-watt meter was reading 5.6w of output, which comports pretty well to a 1amp charge power. That is about 89% conversion efficiency at 1amp. That is on the high end, but within reason for efficiency. If it is actually .85A, then the efficiency is pretty darned low (76%). I can't see any text anywhere on my charger other than NOOK written on it.

Most of my other USB chargers are in the 85-90% efficiency range.

Since it'll charge off of a computer USB port, really any amperage USB wall adapter will work. Unless there is something badly flawed with the battery, using a higher amperage wall charger won't result in any issues. It'll only draw as much amperage as the charge circuits will allow (so long as it is still a 5v charger).

Out of curiousity though, I am going to try my 1amp, 1.2amp and 2.1 amp USB wall chargers to see just how much it actually draws from each.

Timur · 02-01-2012, 12:32 PM

Quote:

Originally Posted by azazel1024

Mine appears to be rated at 1amp, as my kill-a-watt meter was reading 5.6w of output, ...

I am curious, does your kill-a-watt show apparent power also(the one in VA instead of W)? Can you tell me what it says if your device has that feature?

On a sidenote, have you checked the space between the pins on the Nook charger for the script?

azazel1024 · 02-01-2012, 04:17 PM

Sure, I can check that out. I did check the back between the pins and didn't see anything, but I'll take an even closer look tonight.

As a note, the 5.6w was measured connected to my iPad 2, as I knew it would draw max from the charger. The nook may actually charge at less than whatever that translates to as at the USB side power levels as it may cap out below what the USB charger is capable of, though likely it'll max it out when charging.

At a guess on the VA, looking at other chargers, it is probably also in the .8 power factor range, so probably around 6.5-7VA.

Tinderbox (UK) · 02-01-2012, 05:49 PM

I have the UK version of the Kill_A_Watt Meter, How accurate is it really on such low power devices.

John.

http://en.wikipedia.org/wiki/Kill_A_Watt

azazel1024 · 02-02-2012, 09:30 AM

supposedly to within .1w, which can be a pretty high margin for error when you are talking something only pulling 1w, but once you get up to 5 or 6w that isn't a whole lot of margin for error.

I've only tested it against my volt/ammeter once on something, but they came out to effectively the same reading, so I trust it pretty far.

As far as I know, it will NOT accurately measure things under 1w though. So if you attempt to check something like the power draw of a plugged in, "non-operating" wall wart or other charger, it is unlikely to be telling you the true story if it says 0w, as most wall warts (even new switching kinds) will draw at least a tiny amount of power when plugged in and not charging (new ones are low, just a few dozen to maybe a couple of hundred milliwatts, but it is something).

01-30-2012, 10:30 AM	#1
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	Charge time? So what is the charge time like for most people from computer and wall adapter? I haven't charged directly off my computer, at least not from empty, but BN claims 3 1/2hrs. They also seem to claim the same amount in 1 or 2 places about the wall adapter. However, I checked my nook wall adapter, which isn't labeled with its power specs, and it churns out 5.6w from the wall, so I assume it is a 5v 1amp adapter (running about 90% conversion efficiency from 120v mains). I'd assume with twice the power of a regular computer .5amp USB port, the charge time would be something roughly half that off a computer port. So if ~3 1/2hrs from a computer, roughly 2hrs from a wall adapter that can manage 1amp. Does that sound about right? I am still working on the wonky battery issues I am having with my Nook ST, and just trying to get a feel for what a properly working one should manage from a wall adapter. My most recent charge took somewhere around 1:45hrs from the wall adapter and it was hooked up to my computer first for about 10-15 minutes transfering some books and a few new wall papers. That at least sounds like that should be roughly a full charge from zero (it refused to power on any more the battery was so depleted).

01-31-2012, 07:55 AM	#3
RAH Guru Posts: 611 Karma: 575652 Join Date: Oct 2010 Location: Hampton, NH Device: Color Nook; Nook Touch	Same for me - with the wall charger, always about 2 hours from about 25% to 100%. As you know, from another thread, I also have trouble with the battery in my Touch. I wonder if this might be caused by the more rapid charging using the wall charger. In other words, I wonder if I used the computer to charge from 25% to 100% if the battery might be better behaved. I have never tried it; guess I should, huh! Last edited by RAH; 01-31-2012 at 07:58 AM.

01-31-2012, 04:40 PM	#8
Tinderbox (UK) Connoisseur Posts: 60 Karma: 40 Join Date: Jul 2010 Location: England, United Kingdom Device: Nook Simple Touch, Kindle DXG	How many mah is the included touch usb charger, mine did not come with one, I am in the UK, so the US charger would need an adaptor anyway, so it`s not missed, usb chargers are cheap to buy anyway. I will take a guess at 700mah John. Last edited by Tinderbox (UK); 01-31-2012 at 05:03 PM.

02-01-2012, 05:49 PM	#13
Tinderbox (UK) Connoisseur Posts: 60 Karma: 40 Join Date: Jul 2010 Location: England, United Kingdom Device: Nook Simple Touch, Kindle DXG	I have the UK version of the Kill_A_Watt Meter, How accurate is it really on such low power devices. John. http://en.wikipedia.org/wiki/Kill_A_Watt Last edited by Tinderbox (UK); 02-01-2012 at 06:05 PM.

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01-30-2012, 11:46 AM	#2
afv011 Captain Penguin Posts: 2,947 Karma: 2077653593 Join Date: May 2009 Location: Vancouver, BC Device: Kobo Libra 2, Nook Glowlight	That sounds about right. I only charge from the wall charger, and it never takes more than 2 hours.

01-31-2012, 09:58 AM	#4
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	Yeah I don't have a solid idea yet how mine will behave in either scenario, but I did see about a 2% battery drain over 30hrs after a wall charge, with just a little bit of use in there (maybe 5-10 minutes). I then hooked it up to my computer after those ~30hrs to transfer a couple of other books and just top off the charge, which took about 10 minutes hooked up to the computer before it wouldn't charge further. I am at 97% charge now after around an hour and a half or so of reading time and 36hrs. Though I have noticed the battery reading seems pretty temperature sensitive with just a few degrees F temperature difference leading to at least a handful of percent difference in battery reading (at least when partially discharged). For now though, either in full wall charge or topping off on my computer, I am going to "assume" it is charging and working fine until it proves completely otherwise. I will keep rebooting right after a full charge...just in case that is what is keeping it from fast draining. I can certainly see how, between how temperature sensitive the reading is, that a computer hookup/low amp USB hookup could result in the battery actually charging a bit more than it would off of a wall charger. The faster charging of the wall charger would lead to a slightly higher battery temperature which would likely cause the nook to stop charging sooner as the voltage reading on the battery is going to be higher for a lower state of actual capacitance in the battery. That said, honestly I doubt the real difference is more than a few dozen milliwatt hours of extra charge getting squeezed in at the lower amperage charging rate (maybe 1-2%). It does make me feel better that the overall charge time on the wall adapter is roughly correct to get from about 0 charge to a full charge and that my nook probably wasn't actually shutting off and refusing to reboot with anything remaining in the tanks.

01-31-2012, 10:43 AM	#5
RAH Guru Posts: 611 Karma: 575652 Join Date: Oct 2010 Location: Hampton, NH Device: Color Nook; Nook Touch	I have a related question. If I tethered the Touch to my computer via USB, I can transfer files to and from it, etc. It also charges. My question is - if I use the Windows tray icon to disconnect the Nook, will it still charge? In other words, I leave it connected to the USB port, but I have already told Windows to disconnect the Nook device and it has. At that point, the device is no longer shown on the computer, but it is still physically connected to the USB port. Does it still charge? If it does still charge, this seems to me to be the safest way to charge via the computer, instead of leaving it connected and still active as a device on the computer.

01-31-2012, 11:13 AM	#6
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	Yes, it continues to charge over the USB port even if you "eject" the nook from the systems tray.

01-31-2012, 04:28 PM	#7
RAH Guru Posts: 611 Karma: 575652 Join Date: Oct 2010 Location: Hampton, NH Device: Color Nook; Nook Touch	Thanks for the info! Next time it needs a charge (it's at 65% right now), I'm going to charge it the whole way with the computer and see how it behaves aftetward.

02-01-2012, 11:42 AM	#10
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	Mine appears to be rated at 1amp, as my kill-a-watt meter was reading 5.6w of output, which comports pretty well to a 1amp charge power. That is about 89% conversion efficiency at 1amp. That is on the high end, but within reason for efficiency. If it is actually .85A, then the efficiency is pretty darned low (76%). I can't see any text anywhere on my charger other than NOOK written on it. Most of my other USB chargers are in the 85-90% efficiency range. Since it'll charge off of a computer USB port, really any amperage USB wall adapter will work. Unless there is something badly flawed with the battery, using a higher amperage wall charger won't result in any issues. It'll only draw as much amperage as the charge circuits will allow (so long as it is still a 5v charger). Out of curiousity though, I am going to try my 1amp, 1.2amp and 2.1 amp USB wall chargers to see just how much it actually draws from each.

02-01-2012, 04:17 PM	#12
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	Sure, I can check that out. I did check the back between the pins and didn't see anything, but I'll take an even closer look tonight. As a note, the 5.6w was measured connected to my iPad 2, as I knew it would draw max from the charger. The nook may actually charge at less than whatever that translates to as at the USB side power levels as it may cap out below what the USB charger is capable of, though likely it'll max it out when charging. At a guess on the VA, looking at other chargers, it is probably also in the .8 power factor range, so probably around 6.5-7VA.

02-02-2012, 09:30 AM	#14
azazel1024 Groupie Posts: 182 Karma: 346596 Join Date: Jan 2012 Location: Ellicott City, MD Device: Nook simple touch, iPad 2	supposedly to within .1w, which can be a pretty high margin for error when you are talking something only pulling 1w, but once you get up to 5 or 6w that isn't a whole lot of margin for error. I've only tested it against my volt/ammeter once on something, but they came out to effectively the same reading, so I trust it pretty far. As far as I know, it will NOT accurately measure things under 1w though. So if you attempt to check something like the power draw of a plugged in, "non-operating" wall wart or other charger, it is unlikely to be telling you the true story if it says 0w, as most wall warts (even new switching kinds) will draw at least a tiny amount of power when plugged in and not charging (new ones are low, just a few dozen to maybe a couple of hundred milliwatts, but it is something).