Charging with USB - Nexus S General

Hello everyone!
Not sure if this is normal, but I don't think so.
So my problem is that charging with USB is very, VERY slow! But if I recall correctly, it was normal in that first weeks... But after like a month or so, I noticed that it's very slow compared to normal AC charging.
Its like 75% slower via USB. Im on NexusBeam v4.2.3 (ICS), but it occurs on other ROMs too.
Any ideas?

USB power is considerably less than socket power >…>
Sent from my ice cream powered Nexus S

It was the same with my former iPhone. Charging with USB took much longer and I only used it when I already had lots of battery left and was just syncing it.
I kept a separate cable just for charging so I wouldn't have to switch them back and forth.

USB cannot provide the amount of power that an electrical socket can that's why. It'll be slower no matter what phone or ROM you have.

USB ports provide around 500mA of power, the wall charger that came with my phone provides 700mA. So it's kinda faster. (Some MSI boards I have seen have a toggle to disable data for a usb port but provide more power, around 1Amp, Some external hard disks do this too by using 2 USB ports at once)

Related

USB Fast Charging?

Came from a TP2 and I could charge via USB at around 900 mA using fast charge driver.
Since I am a complete Android n00b, and an EVO n00b I have two questions.
1. Are there any apps out there that can show you how fast the battery is charging and discharging? I had one called Battery Monitor in WM, and I want an Android version of that.
2. It appears that USB charging is quite slow. Can anyone confirm the speed at which this phone charges via a USB port?
3. Is there a way to make this faster?
TIA!!
1. Are there any apps out there that can show you how fast the battery is charging and discharging? I had one called Battery Monitor in WM, and I want an Android version of that.
2. It appears that USB charging is quite slow. Can anyone confirm the speed at which this phone charges via a USB port?
3. Is there a way to make this faster?
A 1. I don't believe there is one (someone correct me if wrong), but there are apps to monitor your battery percentage.
A 2. Not sure, shouldn't be too long, how long is it taking yours?
A 3. I don't believe so.
Hero's Hero said:
1. Are there any apps out there that can show you how fast the battery is charging and discharging? I had one called Battery Monitor in WM, and I want an Android version of that.
2. It appears that USB charging is quite slow. Can anyone confirm the speed at which this phone charges via a USB port?
3. Is there a way to make this faster?
A 1. I don't believe there is one (someone correct me if wrong), but there are apps to monitor your battery percentage.
A 2. Not sure, shouldn't be too long, how long is it taking yours?
A 3. I don't believe so.
Click to expand...
Click to collapse
Thanks...Not sure how long it takes as I havent had the phone too long. I know while plugged into my computer last night it wouldn't charge very well.
Computers have much lower power than a wall socket. If you want to charge the EVO fast use the wall plug. Anyone who uses a Mac and the wired keyboard should know what I am talking about.
Please search before posting...
http://forum.xda-developers.com/showthread.php?t=591041
A USB port provides 500ma of power, you can get micro USB cable that will Y off and plug into two USB ports, providing 1000ma of power.
Grims said:
A USB port provides 500ma of power, you can get micro USB cable that will Y off and plug into two USB ports, providing 1000ma of power.
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Click to collapse
Every computer I owned charged my TP2 at around 800-900 mA as long as the fast charge driver was on the phone.
So I know for a fact that it's possible. It's limited by the phone, not the USB port. Appreciate the reply, but did you read Negrito's link?
And Negrito, I did search... This forum.... No hits. I see the link you provided was in the Hero forum. I didn't realize that the fast charge USB issue was affecting other Android phones as this is my first.
supdawg said:
And Negrito, I did search... This forum.... No hits. I see the link you provided was in the Hero forum. I didn't realize that the fast charge USB issue was affecting other Android phones as this is my first.
Click to expand...
Click to collapse
My bad broseph, totally forgot im still subscribed to Hero threads. I just switched to the Evo Launch day.
Its not really an issue per se as that's how all phones normally operate. On WinMo we just got spoiled my No2Chems hack. Anyone know if No2Chem made the jump to Android?
I have seen a lot of familiar names on the Evo forum, like OMJ, and Caulkin!!! I cant wait until someone comes up with an untethered root option and how to bypass the NAND cause I know the ROMs are just going to be simply amazing.
Was digging around in the custom menus, can't remember which one, but one of the ones that you type ##numbers# and enter your MSL and there was a check box for USB charging. Mine was unchecked for some reason. I left it alone but wonder if that makes a difference?
I've tested a few charging scenarios and can tell you that using a wall charger that outputs 1000 ma will help speed up the charge.
These from Monoprice work very well:
http://www.monoprice.com/products/product.asp?c_id=103&cp_id=10311&cs_id=1031106&p_id=6767&seq=1&format=2
want the same thing for the car?
try this one.
Here's the link to a micro usb cable at monoprice for $1.20.
There's a nice Rosewill 4 port charger, that will output 2000 ma IF you have only one device plugged in. With two devices plugged in, it falls back to 1000 ma (still really good). I have this in the kitchen for the kids to jack their various usb things in for charging.
The thing to remember is that the phone will pull as much as it can (most recent phones can pull between 750 and 1000 ma.) What will cause it to charge slower is not usually a software setting, it's having a port that will only put out 500 ma or less...which is what many computers output.
Sean
there is an option in settings /devolopment for usb charging doesnt ssy what it does though
I don't think mine has taken more than 4-5 hours to fully charge and signal strength isn't the greatest at my house so that probably has an impact on it as well... I've no idea if that's normal for a smartphone or if it's considered slow, I don't think my Sony Ericsson feature phone was any faster but the battery indicator on that thing was wildly inaccurate anyway.
My EVO seems to charge just as fast w/the included HTC adapter as with a generic Philips one I had, as well as one of those retractable cables. I was afraid that cable wouldn't be very well shielded and it wouldn't charge right but it seems fine, I'll only be using it when I travel anyway.
Negrito said:
My bad broseph, totally forgot im still subscribed to Hero threads. I just switched to the Evo Launch day.
Its not really an issue per se as that's how all phones normally operate. On WinMo we just got spoiled my No2Chems hack. Anyone know if No2Chem made the jump to Android?
Click to expand...
Click to collapse
No one has seen nor heard from No2Chem in months... Some people think he may have died
I could charge my Touch Pro 2 in about an hour or two using a standard usb plug on any computer I owned.
Might I add the Touch Pro 2 and the EVO share the same identical battery. The EVO obviously draws more current..... I found while using my EVO while plugged into a computer, it barely charges at all. My guess is its discharging while charging at a very similar rate.
Contrary to what most of you are saying, the ma rating of the charger really makes no difference as the phone (and prior htc phones) will pull <500ma if they detect they are plugged into a computer or non-official charger and 1a if they detect an htc charger (which can even damage 500ma chargers). The way this is detected is through grounding of one of the microusb pins in the official charger (and indeed many generic chargers but not all will be detected this way). Absent this grounding (I forget which pin), it will charge at a slower speed. I know of cheap 500ma chargers which have been caused to smoke by attaching a cable with that grounding fooling the phone into thinking it is an oem charger. Many chargers labeled 1a will charge at the 500ma rate as well.
Also, modern computers are fully capable of outputting 1a of power through the usb port. While the spec indeed is 500ma, with a proper cable (or the fastcharge driver for windows mobile), you can force a 1a power draw without any issues. Cheap usb hubs or cheap usb power ports may run into issues.
I'd love to see a solution for android but I don't think one exists.
Actually the HTC battery Widget will show you if you are on AC (1A) or USB (500ma) charge. You can get this widget from the market (not sure why it is not included in the phone in the first place).
I think that the grounding pin is likely the trick and I will be searching the web to see if I can locate it. I have an older battery pack from APC that can output 1.6A but the only way to get the EVO to charge as if it was on "AC" is to use the HTC plug, and then quickly, before the charge light goes out switch to my alternate source. This seems to trick the EVO into thinking that it is still plugged in to the official charger.
This is of course trickier with my car charger, which has been very frustrating - using the phone for navigation and plugged in via usb usually has the battery draining rather than charging!
I wish there was an easy way to fix this, my old phones always attempted to pull as much current as they needed.
My friend uses a 2A charger for his HTC touch pro 2, and it uses the same battery as the EVO if u guys didnt know.
i havent tried it on my evo, but being its from htc too (and uses the same battery)... id expect it to work with that much current.
I currently use a 900mA one in my car, and i do notice that if i use something less than that i tend to get feedback from the audio jack that connects to my cassette player
Found a discussion on this on the android forums relating to the HTC Desire:
<Too new of a user, system won't let me post the link>
I opened a car charger and shorted pins 2 and 3, and the phone did show charging over AC (2 and 3 are the data pins, 1 & 2 are power). My multimeter was acting up, so I am not sure whether the EVO is actually pulling more current - it does appear to be charging faster.
If you try this make sure of 2 things:
1. You charger is capable of 1A.
2. If you choose to short the pins on a USB cable make sure this cable never gets plugged in to your PC.
Rennat said:
Computers have much lower power than a wall socket. If you want to charge the EVO fast use the wall plug. Anyone who uses a Mac and the wired keyboard should know what I am talking about.
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Click to collapse
I know what you mean! Haha
supdawg said:
Came from a TP2 and I could charge via USB at around 900 mA using fast charge driver.
Since I am a complete Android n00b, and an EVO n00b I have two questions.
1. Are there any apps out there that can show you how fast the battery is charging and discharging? I had one called Battery Monitor in WM, and I want an Android version of that.
2. It appears that USB charging is quite slow. Can anyone confirm the speed at which this phone charges via a USB port?
3. Is there a way to make this faster?
TIA!!
Click to expand...
Click to collapse
For your Q #1 search the market for Battery Indicator, great simple app that gives you a battery percentage and how long you have been plugged in or unplugged.

PC USB charging a dead-battery Atrix.. Impossible?

I woke up this morning and the battery of my Atrix was completely dead. Since I was in a hurry to get to work I thought I'm going to charge using the computer in my office with the supplied USB cable.
It appears that the phone won't charge from 0% turned off! I had to borrow a Blackberry wall charger from a college and jump start the Atrix before plugging it to my computer's USB and start charging.
My iPhone 3GS would come back to life if plugged to the USB port after a complete discharge.
Is there a solution for the Atrix? Are there other android devices you know of with the same issue?
Thank you
my milestone also have this prob
The moto wall chargers run at 800+ma. This is more than the usual ~400-600ma that other chargers run at. Computer USB ports only supply 500ma MAX. The atrix doesn't seem to like anything under ~600ma and prefers 800-1000ma for some weird reason.
If you've got a well powered USB port, it will charge the phone. If it's underpowered, the phone won't even take the charge.
Yes, from a dead batt, the phone wont even wake up the charge circuit for anything under 600ma. I've experienced it as well.
Thank you. What about USB 3.0? I have that in my home PC. But it still sucks how I can't wake up the phone if the battery completely drained with all the USB around me at work or wherever when a wall-charger is not within reach.
Shouldn't the phone preserve the last drops of the battery before shutting down so it allows us time to start it up again and charge by USB 2.0?
I think it wouldn't hurt if Motorola made it shutoff at like 2% allowing us to charge the device and get it up using USB 2.0. Or maybe a dev can get around it as an optional tweak for users?!
That also made me think of something else. Would the alarm go off if the battery completely died while you were asleep? I know iphone, Nokia and probably many other smartphones does that (preserving last drops for this purpose).
all usb has the same voltage specs, 3.0 ports wont charge better than 2.0 ports on the same system, the only thing that will make a difference is the build quality of the hardware and the voltage regulation from the power management.
A powered usb hub would be your best bet if you can't get to a moto charger
diedemus said:
all usb has the same voltage specs, 3.0 ports wont charge better than 2.0 ports on the same system, the only thing that will make a difference is the build quality of the hardware and the voltage regulation from the power management.
A powered usb hub would be your best bet if you can't get to a moto charger
Click to expand...
Click to collapse
I thought it's better to bring up this thread instead of opening a new one since I've been investigating the same issue.
We all know that Android phones and widgets especially can drain the battery unexpectedly.
I PM'ed kennethpenn if there's a way to automate a shutdown when the battery reaches a certain level so it can charge and wake up connected to a computer USB 2.0 port (As in if it can be implemented in his ROM). Kenneth replied that he's not sure, and I've been looking for an app that can do that.
Now before we go more on that, I wish to have your opinion on how important you think it is to sacrifice the last little drops of the battery in favor of being to charge/wake up your devices when you're on the go and may not have access to wall charger?
If there's an app that can allow it then I'm welling to do the tests and find the sweet spot of when to shutdown and if it would actually charge to wake up.
Thank you
I had the same problem yesterday, I only have the USB cord with me and I thought my phone was dead for real or defective. Thanks god for XDA ... The user manual did not say anything about computer usb power not being powerfull enough.
CyberPunk7t9, there is (a few) threads dedicated to improving Atrix battery life full of usefull tricks. I did not try it yet, but SetCPU might be of a great help too.
Remeber, the Atrix requires the Motorola usb drivers to be installed to charge the phone off a port. If the phone is off, your computer is not reconigizing that it was plugged in, so the drivers do not start. *I could be wrong* Happen to me last night though
it's a hardware issue on the computer side. without the moto drivers there telling the USB port to up the current coming out, your phone won't charge on it. most computer-based USB ports do not run high current for power purposes unless enabled. it cannot be solved with an app and mandating a shutdown at 2% is most likely going to cause more problems than solve. the solution is to not run your battery down, honestly. you shouldn't be for LiPo batteries anyway.
diedemus said:
all usb has the same voltage specs, 3.0 ports wont charge better than 2.0 ports on the same system, the only thing that will make a difference is the build quality of the hardware and the voltage regulation from the power management
Click to expand...
Click to collapse
It's not voltage that matters, it's current.
I have a gigabyte board which has 'rapid charge' technology, meaning it supplies extra amperage to the usb ports...my battery was close to dying when I saw this thread so as a test I let it completely die and then I tried charging from usb.
Result: It worked.
I still don't get as quick of a charge from USB as I do from the wall but at least there is enough amperage to charge from a completely dead state.
diedemus said:
all usb has the same voltage specs, 3.0 ports wont charge better than 2.0 ports on the same system, the only thing that will make a difference is the build quality of the hardware and the voltage regulation from the power management.
A powered usb hub would be your best bet if you can't get to a moto charger
Click to expand...
Click to collapse
Get your facts straight!..............USB 3.0 IS a powered USB port!
USB 3.0 will charge more devices, quicker
Not only will USB 3.0 cables facilitate faster transfer speeds, but they’ll carry more power, too. The USB-IF recognizes the growing number of portable devices that charge via USB (cellphones, MP3 players, digital cameras), and have bumped the power output from about 100miliamps to 900 milliamps. That means not only will you be able to power more than 4 devices from a single hub, but the increase current will let you charge up heftier hardware as well.
Maximum PC
<edit> Also, my Atrix charges fine off the 3.0 ports on my HP laptop.
dcarpenter85 said:
I have a gigabyte board which has 'rapid charge' technology, meaning it supplies extra amperage to the usb ports...my battery was close to dying when I saw this thread so as a test I let it completely die and then I tried charging from usb.
Result: It worked.
I still don't get as quick of a charge from USB as I do from the wall but at least there is enough amperage to charge from a completely dead state.
Click to expand...
Click to collapse
I have a gigabyte UD7 in my PC. I wanted to use the rapid charge feature for a while. Still planned. Also the On/Off Charge feature to charge the iphone/ipod while the computer is turned off. I will probably assign some time to test those tomorrow.
CaelanT said:
Get your facts straight!..............USB 3.0 IS a powered USB port!
USB 3.0 will charge more devices, quicker
Not only will USB 3.0 cables facilitate faster transfer speeds, but they’ll carry more power, too. The USB-IF recognizes the growing number of portable devices that charge via USB (cellphones, MP3 players, digital cameras), and have bumped the power output from about 100miliamps to 900 milliamps. That means not only will you be able to power more than 4 devices from a single hub, but the increase current will let you charge up heftier hardware as well.
Maximum PC
<edit> Also, my Atrix charges fine off the 3.0 ports on my HP laptop.
Click to expand...
Click to collapse
I have USB 3.0 in my PC too. But as someone stated here, USB 3.0 does not provide more voltage than USB 2.0. Just more consistency I think.
But what matters, Can any of those solutions charge and start a completely dead Atrix?
Thank you for participating guys.
USB ports can only source 100mA unless the host and client agree to a higher current. If as mentioned the Atrix needs more then this to wake-up the phone with a dead battery then it can never request the higher current. This is also why the Moto drivers need to be installed to get the higher current.
CyberPunk7t9 said:
I have USB 3.0 in my PC too. But as someone stated here, USB 3.0 does not provide more voltage than USB 2.0. Just more consistency I think.
But what matters, Can any of those solutions charge and start a completely dead Atrix?
Thank you for participating guys.
Click to expand...
Click to collapse
you need a port or power source that will supply enough current to the phone. period. if your computer's ports don't do it, it won't work. go find a higher amp USB port.
Maybe try the usb 2 to 1 cable? So you plug it into 2 usb ports and than into the atrix
CaelanT said:
Not only will USB 3.0 cables facilitate faster transfer speeds, but they’ll carry more power, too. The USB-IF recognizes the growing number of portable devices that charge via USB (cellphones, MP3 players, digital cameras), and have bumped the power output from about 100miliamps to 900 milliamps.
Click to expand...
Click to collapse
Actually USB 2.0 can supply 500 mA, but as someone said to get more than 100 mA, the host and device have to 'negotiate' which I think means driver support of some kind.
I have noticed in Device Manager says that my SGS plugged into my laptop as a mass storage device is only taking 100 mA, but it doesn't charge much slower than it does from a wall charger (which is actually pretty slow, almost 3 hrs for a full charge). Still if I do the math to charge 1500 mAh at 3.7V with 5v in 3 hours would take about 370 mA (assuming 100% efficiency, so the actual current draw must be higher).
If anyone knows a more accurate way of determining the current a USB port is supplying, since Device Manager seems to be wrong, that would be interesting information.
What's interesting here is that at 0% the device isn't even on and can't power up to negotiate a higher current draw. If it can't turn on with 100 mA from the charging port it's stuck, which I suspect is the problem here with the Atrix.
USB 3.0 has the potential to charge at 900mah but yes it’s still 5vdc, the phone will not pull more than 500mah unless it detects the data lines are bridged. This is a safety feature so it doesn't blow your usb2.0 ports as the phone wasn’t built with usb 3.0 spec in mind. If you have a 3.0 usb port you can make a fast charge cable with the data lines cut and bridged, make sure you cut them and they aren't still connected to the host side or you might kill your port.
callen81 said:
USB 3.0 has the potential to charge at 900mah but yes it’s still 5vdc, the phone will not pull more than 500mah unless it detects the data lines are bridged. This is a safety feature so it doesn't blow your usb2.0 ports as the phone wasn’t built with usb 3.0 spec in mind. If you have a 3.0 usb port you can make a fast charge cable with the data lines cut and bridged, make sure you cut them and they aren't still connected to the host side or you might kill your port.
Click to expand...
Click to collapse
mA, not mAh
dLo GSR said:
mA, not mAh
Click to expand...
Click to collapse
I'm so used to talking about batteries I guess I left the "h"ours in, haha.

Impossible to charge sg2 in car

Hi all, just came 3 days ago from an htc hd2, and so far I am more than happy with it.
I have only one complaint and maybe you guys will help me sharing your experience : I can't charge this phone in my car while using gps.
It seems that the power adapter is not powerful enough to charge the phone screen on.
The car charger has a 5v 1000ma output, more than the regular wall charger provided by Samsung and it was working well before with my HD2 so I have no clue about this problem.
Did you experience that issue too, else can you share what car charger do you use?
try to buy new standard car charger with micro plug.. 13 eur and you will be saved..
Sent from my GT-I9100 using XDA App
Charger doesn't matter unless the phone is dropping into USB charging mode - phone limits to around 600-650 mA by default.
Custom kernels can bump this limit up for I9100 users. I777 users are screwed - we've got a crippled charger chip.
I had the same problem, I used the samsung one, useless, so I used my iPad charger, which is 2A, and charges the iPad quick, still useless. We drove from Bathurst NSW, down to Melbourne, about 10 hour drive, plugged in all the way using GPS, and about an hour from home, the connect to charger warning came on!! So once I stopped GPS, it started taking charge. Looks like when the phone is in use, it draws more then it takes charge, plus I read somewhere on here the phone is limited on the charge it takes, so using the 2A does nothing different then the stock 500mA charger.
I always had this problem with my Nexus One, although they are different phones, the problem is the same, uses more power then it can recharge in USB mode.
After trying 3 or 4 different charges I remember that I found one ultra-cheap 'made in taiwan' from a street seller that worked very well.... so it's kind of a lucky shot!
good luck!
Im using a genuine Samsung SGS2 charger and I can charge and run Sygic just fine. I started my journey with 80% and 40mins later I was up to 91% when I stopped and got out. (not in aeroplane mode..)
Very interesting feedbacks... So that confirm that is clearly not a matter of output amperage power.
It is now the same problem on the galaxy tab 10.1, for quickly charge this tab you need the Samsung compatible usb adapter.
It can be likely with a tab bringing a proprietary plug, but I didn't thought it will be the same with a Samsung phone bringing a regular micro usb plug. Quite frustrating and disappointing!
I will search around a micro plug car charger as suggested by redzion, but actually I don't clearly see the difference with my usb charger + a micro usb cable.
Double post, sorry.
If I use the usb cable from my cd player I have the same problem but if I use the official Samsung car charger Ithe only problem I have is the phone getting stupid hot
Sent from my GT-I9100 using xda premium
Oh Samsung, when you will understand?!
Samsung DOES follow the USB charging standard - it goes to its highest current setting when a charger that follows the standard is connected.
Note that iPad/iPhone chargers do NOT follow the standard - Samsungs will treat these as USB hosts and limit to 450 mA instead of 600-650.
Modified kernels can increase both of these values on I9100s.
The only thing Samsung really did **** up is counting screen/CPU current usage against the charge current limits - that's just stupid.
So the charger has smarts. On the i9000 factory chargers, the data pins were bridged. Bridging these pins manually on a USB cable when connecting to a USB source (such as a PC) enabled full current charging. You can see this in Settings -> About; it will say either USB or AC charging.
Do you think this is the case with the i9100?
I don't condone testing this theory on your i9100. Increasing the max current via custom ROM may be a safer solution.
I had the same problem. Two things fixed it for me:
1) I bought this charger: Sony Ericsson AN300 Micro USB 10€
2) I am using a custom kernel now
Any charger that is rated at 1000mA or more (per port) will do just fine. The problem is the cable - you need a quality microUSB cable, or it won't provide all the juice you need. I had the same issue, and I swapped three chargers until I found the real culprit.
Try with the charger you have now and the mUSB cable that was in the phone box - it should work well with that one.
I just press the power button to turn the screen off. when i need the sat nav i press the power and it still tracks you so there is no delay. With the screen off it does charge.
same problem
Duffman19 said:
I just press the power button to turn the screen off. when i need the sat nav i press the power and it still tracks you so there is no delay. With the screen off it does charge.
Click to expand...
Click to collapse
You are right, but even if it is better than nothing the charging time is still a big problem.
Yesterday I drove for at least 40mn phone off. Arrived to destination, I turn the device on: it charged only from 0 to 5%
I would like to test the mariusi theory concerning the Samsung micro usb cable, unfortunately on my SgsII box I just have a wall charger, no a microusb-usb cable.
Entropy512 said:
Samsung DOES follow the USB charging standard - it goes to its highest current setting when a charger that follows the standard is connected.
Click to expand...
Click to collapse
Is there a way to know before buying if the charger respect this charging standard?
I have some cheap usb chargers here and no one is a fast as the one provided by Samsung.
Entropy512 said:
The only thing Samsung really did **** up is counting screen/CPU current usage against the charge current limits - that's just stupid.
Click to expand...
Click to collapse
Maybe for safety purpose? Gps phones can become very hot behind the car glass.
Samsung are trying to "encourage" you to buy only their official accessories. To do this they've wired something differently in their chargers and cables. This "problem" exists on the Galaxy Tab too and can be solved with this adapter...
http://www.ebay.co.uk/itm/USB-car-w...ccessories&hash=item2c5c07736b#ht_3084wt_1163
It's cheap and turns a trickle charge into a full charge. I don't know the specifics of what they've done, but their USB charging just isn't the same as most others manufacturers.
Archer said:
It's cheap and turns a trickle charge into a full charge. I don't know the specifics of what they've done, but their USB charging just isn't the same as most others manufacturers.
Click to expand...
Click to collapse
Great find.
Pretty sure it just bridges the data pins.

Charging only when powered off

I woke up this morning and noticed my Nexus 7 was down to 15% charge so plugged it in (using the same cable, etc) that I have been using. It failed to register that it was charging. I tried several different cables and wall adapters and then nandroided back to a previous rom (I was running a test version from one of our developers). Nothing has made a difference. The tablet only charges when powered down, which also means it can't be connected via usb to a computer. This issue has been noted in several forums since the last jb update but I can't find a solution. Any ideas?
Sent from my ADR6425LVW using Xparent Red Tapatalk 2
Dancershrink said:
I woke up this morning and noticed my Nexus 7 was down to 15% charge so plugged it in (using the same cable, etc) that I have been using. It failed to register that it was charging. I tried several different cables and wall adapters and then nandroided back to a previous rom (I was running a test version from one of our developers). Nothing has made a difference. The tablet only charges when powered down, which also means it can't be connected via usb to a computer. This issue has been noted in several forums since the last jb update but I can't find a solution. Any ideas?
Sent from my ADR6425LVW using Xparent Red Tapatalk 2
Click to expand...
Click to collapse
Question, do you try to charge it off your computer or off the provided separate charger? Because right now i'm almost done charging my n7 via USB off my craptop because i've managed to forget my charger at my other location (god it's sloooooooooow), but it's still charging none the less.
The issue with charging from USB ports off your pc is that some PCs are unable to provide enough juice to power your device, and because of that your device may fail to identify that it's actually charging (may be some os-level function that disables charging if it detects that your hub device cannot supply enough power that is not available when shut down or just simply because powered-down device uses less power than the powered-up one).
Anyway, i'd not recommend charging your tablet devices off the PC USB ports because those are simply not designed for this (unless you have a motherboard with some USB ports designed specifically with charging in mind, this feature is becoming common in new motherboards and laptops). Another solution would be using the external-powered USB hubs, which can provide higher than standard currents to the ports. Also most of the standard phone chargers cannot provide the required power to charge the n7 either.
[some technobabble]
Li-Ion/Li-Polymer batteries are rated to be charged (the CC stage) at 0.5C - 1C (C is the designation of current to capacity, 1 A per 1 Ah of the battery), and n7 sports 4325 mAh battery, meaning that charging current for the battery should be 2.1625-4.325 A for the CC stage (first stage of charging, amounting for ~80% of the battery's charge). the standard Asus-supplied charger is rated 2000 mA at 5 V, while a standard USB port can only supply around 500 mA (0.5 A) or even less if there are more connected devices. This is why n7 charges much slower when connected to a PC via the USB or even does not charge at all, like it can be in your case. And this is why I recommend not using this method to charge your tablet, for you strain your PC's motherboard and power supply by doing this, and they can eventually fail.
[update]
If your n7 still fails to charge even with the provided charger, try reverting to some of the older stock roms and see if that helps? If it doesn't, you may try to RMA it.
Aessaya said:
Question, do you try to charge it off your computer or off the provided separate charger? Because right now i'm almost done charging my n7 via USB off my craptop because i've managed to forget my charger at my other location (god it's sloooooooooow), but it's still charging none the less.
The issue with charging from USB ports off your pc is that some PCs are unable to provide enough juice to power your device, and because of that your device may fail to identify that it's actually charging (may be some os-level function that disables charging if it detects that your hub device cannot supply enough power that is not available when shut down or just simply because powered-down device uses less power than the powered-up one).
Anyway, i'd not recommend charging your tablet devices off the PC USB ports because those are simply not designed for this (unless you have a motherboard with some USB ports designed specifically with charging in mind, this feature is becoming common in new motherboards and laptops). Another solution would be using the external-powered USB hubs, which can provide higher than standard currents to the ports. Also most of the standard phone chargers cannot provide the required power to charge the n7 either.
[some technobabble]
Li-Ion/Li-Polymer batteries are rated to be charged (the CC stage) at 0.5C - 1C (C is the designation of current to capacity, 1 A per 1 Ah of the battery), and n7 sports 4325 mAh battery, meaning that charging current for the battery should be 2.1625-4.325 A for the CC stage (first stage of charging, amounting for ~80% of the battery's charge). the standard Asus-supplied charger is rated 2000 mA at 5 V, while a standard USB port can only supply around 500 mA (0.5 A) or even less if there are more connected devices. This is why n7 charges much slower when connected to a PC via the USB or even does not charge at all, like it can be in your case. And this is why I recommend not using this method to charge your tablet, for you strain your PC's motherboard and power supply by doing this, and they can eventually fail.
[update]
If your n7 still fails to charge even with the provided charger, try reverting to some of the older stock roms and see if that helps? If it doesn't, you may try to RMA it.
Click to expand...
Click to collapse
The only thing I haven't tried is going back to older roms. I'll give that a shot. Thanks.
Sent from my Nexus 7 using Xparent BlueTapatalk 2
Contacted Google and I should receive my replacement tablet tomorrow. It appears that the only solution is a new nexus 7.
Sent from my Nexus 7 using Xparent BlueTapatalk 2

[Q] Nexus 7 short circut damage help, please.

So, I apparently did something very stupid with my new Nexus 7.
I have a few 1 TB external hard drives, which don't get enough power via an OTG adapter from the Nexus 7 to run. So, I purchased a two into one cable -- that is, a cable that combines two male USB A plugs into one Micro USB B plug so that a USB 3.0 hard drive can use two USB 2.0 ports to have enough power. I had planned to use this to enable use of the hard drives with the Nexus 7 while traveling by plugging one cable in the tablet and the other into a charger.
When I got the cable I tested it by plugging one of the USB A plugs into my Nexus 7, and then I plugged the other into my computer's USB port. The Nexus 7 promptly shut down, the computer complained of a power surge on the USB port, and a distinct smell of melted plastic came from the computer's USB port. I guess the combining cable didn't combine so much as it just acted like a double headed male A USB cable and shorted things out?
The Nexus 7 refused to restart afterwards until I it plugged it into its charger. It works now, mostly. However, if its battery charge is above about eighty-seven percent then it always reports that it is charging, regardless if it is plugged in or not. And if I plug it into a computer while it is reporting that it is charging I have to restart the tablet to get it to connect to the computer -- I guess it thinks it is connected to a charger and doesn't bother checking for a data connection unless restarted.
The level where it stops thinking it's charging varies somewhat -- I've had it still claim to be charging all the way down to eighty-two percent charge, and by repeatedly opening the battery app over and over again I have been able to get it to notice that it's really not charging all the way up to ninety-one percent, but no higher, and I have to open and close the battery app an increasing number of times for every percent that it goes up over eighty-seven before it will notice it's not charging.
Any idea what kind of damage I'm looking at? How to fix it? Whether I can get the warranty people to fix it free of charge? If yes, whether they will send me a new one or just fix the one I have? Whether it's worth getting fixed since it mostly still works, and doesn't really bother me as long as it doesn't get worse?
Nothing?
Nothing from anyone?
Try replacing the internal USB plug? About $25. Easy to do your self.

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