[Q][Solved]My Nexus 7 is very slow to charge

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blissville

Member
May 10, 2013
14
1
I noticed this problem the moment I upgraded from 4.2.2 to 4.3. While charging and am using my tablet, it will be discharging. When the battery is completely drained and I plug in my charger, it wouldn't charge immediately, it wouldn't wake up until after say 10 - 15 minutes before it indicates charging. At this point of I try to put it on, it goes of immediately. I believe this is got to do with the newer versions of android from 4.3 to date. Right now am running kitkat and its not getting any better.I really thought it was my battery.
 

Momogs

Member
Oct 2, 2014
35
6
Reactivate battery

My Nexus 7 (2012) was experiencing the same slow charging issue. Went from 66% to 67% in 4 hours. Then I remembered when I lent my old Galaxy S2 to my brother and the battery wouldn't keep its charge. He took it out of the phone and gave it a couple hard whacks. Presto, the battery started behaving properly. I've given my Nexus 7 to my daughter, but the charging issue has rendered it almost useless. So I thought WTF and gave it two hard smacks on the lower back side. It immediately started charging properly, and was fully charged within an hour. Do it at your own risk, but it worked for me.
 

someone755

Senior Member
Sep 27, 2011
2,048
1,380
Ljubljana
Or rather, don't.
Take it apart and replace the USB connector part, it costs what, $10?
Or take it to a repair shop and it'll be done for you.
 

Yscman

Member
Nov 16, 2012
8
1
São Paulo
OnePlus 7T
Image

Solved! (at least for me)

I suspected this was hardware for a while since this issue would happen no matter what ROM was on there and no matter how many times I did a factory reset. Knowing that I'm just out of warranty and that Asus would probably charge me a hefty fee for fix it, I figured I had nothing to lose. Read my own thread on the issue to see what troubleshooting steps I had already tried here: http://forum.xda-developers.com/showthread.php?t=2390222

Anyway, I took the back off and then removed the battery (the connection was fine btw). I removed the three screws that held the speakers in place. Then, suspecting that the small connections might need to be rewet, I plugged in my soldering iron and rewet the following areas in black (image borrowed from iAppleDev as I forgot to take my own) :



For insurance, I also folded up a small piece of paper and placed it where the blue box is. Screwing the speakers back in place held the paper in place and held the ribbon cable retainer clip against the connectors, giving a stronger connection.

I turned off my Nexus 7 with a 9% battery and then when to take care of other things. Came back in an hour or so (probably less) and I see that the battery is already at 33%! This is with the Asus charger plugged in, which wasn't working at all previously.

Very stoked. Kinda bummed I didn't figure this out before a conference I had to go to last week. Would have been nice to read on my Nexus 7 instead of my phone.

Hey man, can you upload the images again? I want to do that with my nexus 7 but without the image i don't have the courage to do it!

Can you help me please?

Thanks
 

stoatwblr

Member
Sep 12, 2011
42
13
Fastcharge is irrelevant when connected to ac power.

Really? My N7 will ONLY charge at 450mA (measured externally) no matter what the power source is, even when it says it's connected to AC.

I'd be a very happy bunny if it could draw 1A, let alone 2 - it wouldn't go flat on me even when plugged into the charger if it took an extra 300mA and it'd charge in a reasonable period if it took an extra 250mA over that.
 

Sorraia3

Senior Member
Dec 20, 2010
83
4
Right Here
I am having the same issue now and have tried the same troubleshooting, even replacing the battery and the charging port flex cable assembly. I'd like to give this a try since I am also out of warranty. Could you please repost the picture? It is no longer showing. Thanks! :)


Solved! (at least for me)

I suspected this was hardware for a while since this issue would happen no matter what ROM was on there and no matter how many times I did a factory reset. Knowing that I'm just out of warranty and that Asus would probably charge me a hefty fee for fix it, I figured I had nothing to lose. Read my own thread on the issue to see what troubleshooting steps I had already tried here: http://forum.xda-developers.com/showthread.php?t=2390222

Anyway, I took the back off and then removed the battery (the connection was fine btw). I removed the three screws that held the speakers in place. Then, suspecting that the small connections might need to be rewet, I plugged in my soldering iron and rewet the following areas in black (image borrowed from iAppleDev as I forgot to take my own) :



For insurance, I also folded up a small piece of paper and placed it where the blue box is. Screwing the speakers back in place held the paper in place and held the ribbon cable retainer clip against the connectors, giving a stronger connection.

I turned off my Nexus 7 with a 9% battery and then when to take care of other things. Came back in an hour or so (probably less) and I see that the battery is already at 33%! This is with the Asus charger plugged in, which wasn't working at all previously.

Very stoked. Kinda bummed I didn't figure this out before a conference I had to go to last week. Would have been nice to read on my Nexus 7 instead of my phone.
 

germanmarky

Senior Member
Feb 4, 2009
72
17
Boynton Beach
I don't specifically recall where I found the information (may have been this thread), but my Nexus 7 2012 would take forever to charge, and also after it was pulled from the charger would die very quickly. It would also LOSE charge while plugged in if in use.

The information that I found was to instead use the ASUS Nexus 7 Dock (already had one) to completely charge the tablet. Right now, it has been mostly idle with screen off for 2.5 hours, and it is still at 100%.
 

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tremlar

Member
Sep 24, 2014
11
1
Solved! (at least for me)

I suspected this was hardware for a while since this issue would happen no matter what ROM was on there and no matter how many times I did a factory reset. Knowing that I'm just out of warranty and that Asus would probably charge me a hefty fee for fix it, I figured I had nothing to lose. Read my own thread on the issue to see what troubleshooting steps I had already tried here: http://forum.xda-developers.com/showthread.php?t=2390222

Anyway, I took the back off and then removed the battery (the connection was fine btw). I removed the three screws that held the speakers in place. Then, suspecting that the small connections might need to be rewet, I plugged in my soldering iron and rewet the following areas in black (image borrowed from iAppleDev as I forgot to take my own) :



For insurance, I also folded up a small piece of paper and placed it where the blue box is. Screwing the speakers back in place held the paper in place and held the ribbon cable retainer clip against the connectors, giving a stronger connection.

I turned off my Nexus 7 with a 9% battery and then when to take care of other things. Came back in an hour or so (probably less) and I see that the battery is already at 33%! This is with the Asus charger plugged in, which wasn't working at all previously.

Very stoked. Kinda bummed I didn't figure this out before a conference I had to go to last week. Would have been nice to read on my Nexus 7 instead of my phone.

Hi, having a nightmare with my wifes Nexus and I obviously need to do this fix but your image isn't displaying is there any chance you could please re-post the image of where to solder. Really appreciated.
 

bloomer2011

Member
Apr 19, 2011
32
4
There might be a few different causes for similar phenomena, but for me it was an absolutely 100% software issue. After upgrading to KitKat (stock, not rooted), my N7 wifi 32GB would frequently (but not always) charge very very slowly. It appeared to happen almost exclusively when my alarm clock app was keeping the screen awake (faint clock on black background), with the battery charge dropping overnight, rather than improving. This had not been a problem (using the same app version) in JellyBean. If I checked afterwards what was consuming battery, it was always the glgps process (from comments online, people seem confused about what this does, and although it contains the letters "gps", it might instead stand for google play services). I couldn't find any way to kill/control this process successfully.

I upgraded to a Lollipop custom ROM and this was disastrous. The tablet would charge completely unpredictably, regardless of apps or screen on/off. The only reliable way to charge was to turn it off. The process glgps was no longer visible as the culprit (nor was any other process conspicuous).

I downgraded to a KitKat custom ROM (slimkat). For the first day or two, the charging problem still seemed to be present, but since then (three weeks now) the tablet has charged perfectly normally under all circumstances. I have no idea why the first day or two was different. Throughout the testing above, I used the same charger, cable and power outlet. Anyway, hope this additional input helps anyone else.
 

jfmcbrayer

Senior Member
May 9, 2011
219
116
I upgraded to a Lollipop custom ROM and this was disastrous. The tablet would charge completely unpredictably, regardless of apps or screen on/off. The only reliable way to charge was to turn it off. The process glgps was no longer visible as the culprit (nor was any other process conspicuous).

Did you have gapps on this ROM? If so, play services could well have still been the culprit. It seems like Lollipop obscures the process that's to blame for battery usage somewhat, relative to KitKat.
 

mr.crabs!

Member
Aug 19, 2012
28
5
Please, please reupload the image..!

Solved! (at least for me)

I suspected this was hardware for a while since this issue would happen no matter what ROM was on there and no matter how many times I did a factory reset. Knowing that I'm just out of warranty and that Asus would probably charge me a hefty fee for fix it, I figured I had nothing to lose. Read my own thread on the issue to see what troubleshooting steps I had already tried here: http://forum.xda-developers.com/showthread.php?t=2390222

Anyway, I took the back off and then removed the battery (the connection was fine btw). I removed the three screws that held the speakers in place. Then, suspecting that the small connections might need to be rewet, I plugged in my soldering iron and rewet the following areas in black (image borrowed from iAppleDev as I forgot to take my own) :



For insurance, I also folded up a small piece of paper and placed it where the blue box is. Screwing the speakers back in place held the paper in place and held the ribbon cable retainer clip against the connectors, giving a stronger connection.

I turned off my Nexus 7 with a 9% battery and then when to take care of other things. Came back in an hour or so (probably less) and I see that the battery is already at 33%! This is with the Asus charger plugged in, which wasn't working at all previously.

Very stoked. Kinda bummed I didn't figure this out before a conference I had to go to last week. Would have been nice to read on my Nexus 7 instead of my phone.



If anybody has the image referred to in this post PLEASE reupload it. It could really help.

Thank you.
 

zelevw

New member
Sep 13, 2014
3
0
Try this, I worked wonders for me, I´m able to charge my N7 2012 in about 2 hours!

Since I´m not able to post URLs go to YouTube, search for "Slow Charging Fix for Nexus 7" video posted by ianmedina11 and try it...best regards.
 

mr.crabs!

Member
Aug 19, 2012
28
5
Since I´m not able to post URLs go to YouTube, search for "Slow Charging Fix for Nexus 7" video posted by ianmedina11 and try it...best regards.
Thanks dude. Had a go at that one before. Seems more like it is treating the symptoms rather than the cause if you know what I mean. I can't help but feel it is a faulty component somewhere, probably a capacitor within the charge circuit (hence my interest in the original image of this post).

I have handled many nexus 7s and some have had this fault. My son's nexus is just beginning to show this issue.

I feel also that it could be due to the charge port itself, probably oxidation of the contacts (which I think would be helped by the repeated plugging/unplugging as shown in the above video until a good contact is made) or poor solder connections which may be fractured microscopically, reducing the flow of current. I guess rewetting the usb solder connections would help in this instance.

Also could be poor connection between the usb flex and the flex which runs under the battery to the main board. After that it is probably pcb component issue which I'm at a bit of a loss with.

I'm going to investigate my son's tablet and let you know what I find. This issue is annoying and let's see if we can't figure this one out together.

Sent from my SM-G850F using Tapatalk
 

adeelraj

Senior Member
Oct 16, 2011
421
107
Karachi
Thanks dude. Had a go at that one before. Seems more like it is treating the symptoms rather than the cause if you know what I mean. I can't help but feel it is a faulty component somewhere, probably a capacitor within the charge circuit (hence my interest in the original image of this post).

I have handled many nexus 7s and some have had this fault. My son's nexus is just beginning to show this issue.

I feel also that it could be due to the charge port itself, probably oxidation of the contacts (which I think would be helped by the repeated plugging/unplugging as shown in the above video until a good contact is made) or poor solder connections which may be fractured microscopically, reducing the flow of current. I guess rewetting the usb solder connections would help in this instance.

Also could be poor connection between the usb flex and the flex which runs under the battery to the main board. After that it is probably pcb component issue which I'm at a bit of a loss with.

I'm going to investigate my son's tablet and let you know what I find. This issue is annoying and let's see if we can't figure this one out together.

Sent from my SM-G850F using Tapatalk

which usb contacts u are trying to rewet plx post a pic here

Sent from my Nexus 7 using Tapatalk 2
 

mr.crabs!

Member
Aug 19, 2012
28
5
which usb contacts u are trying to rewet plx post a pic here

Sent from my Nexus 7 using Tapatalk 2
I have done some further investigation this evening on my son's tablet with some success.

With his current hardware and with the tablet switched on it was drawing 0.46A from the OEM nexus charger (tried two known good chargers with same results), and 0.7A from my Samsung tablet charger. Both chargers are 5V 2A output. This resulted in very slow charging.

I then tried changing the USB port assembly with two known good ports. Instantly the charging current jumped to 0.81A when using both chargers. I replaced the old charge port assembly and tried again. It was now also pulling 0.81A. I figured this could have been due to either oxidised contacts on the charge port assembly to mainboard flex or on the connector on the charge assembly which this flex fits into. After cleaning both parts it is reliably pulling 0.81A all the time. This is an improvement.

Now I test my own nexus 7 which charges at a rate of about 30-35% per hour and see what it is pulling. Also 0.81A. Feeling happy I have fixed my son's tablet I leave it on charge for an hour. It increases charge by around 18-20%. Not bad. I realise charge progresses in a curved charge graph pattern (i.e is not linear progress) but this is just comparatively speaking. The level of charge in the batteries in both cases was approximately the same and so I can draw that comparison. Besides, having had a lot of these nexus 7s I know roughly what rate it should charge under normal circumstances. Also, android version and kernel are exactly the same on both.

So, I carry on trying to find the source of the reduced rate of charge despite the same current being pulled by both tablets. I try:

(IS IT THE CHARGE ASSEMBLY?):
》Rewet the 5 pins on the back of the micro usb port where they connect to the charge port assembly board.
》Replaced whole assembly again.

(IS IT THE CHARGE FLEX?):
》Cleaning the end of the charge flex where it connects to the CHARGE PORT ASSEMBLY and it's corresponding connector.
》Cleaning the end of the charge flex where it connects to the MAIN BOARD and it's corresponding board connector.
》Changing the charge flex for a known good flex.

(IS IT THE BATTERY?):
》Changing for known good battery.
》Cleaning the battery connector pins on the main board.
》Rewetting battery connector solder points on main board.

None of the above made any difference to the amount of current being drawn whilst charging. HOWEVER, the above could be a solution to your issue depending upon where the fault lies. This is surely why there are so many conflicting methods to solve this issue and why some work for some people and not others. If you have tried the above and no improvement then you are at the same point as I am.

Being a scientist by trade this logical and methodical elimination of possibilities leads me to believe that it can now only be one of two things remaining (unless anyone else has any thoughts?):

》》Hardware fault somewhere else on the circuit board within the charging circuit of the tablet (needle in a haystack?).

OR

》》Firmware/Kernel issue. I have heard that some kernels allow for a so called "fast charge" scenario which appears to help. As both my tablets have the exact same firmware and kernel on them then the only way I can see the kernel to be the problem is if the two tablets have slightly different hardware inside them (known to occur with tablet manufacturing even within the same model number), and the kernel is not functioning the same in the two instances.

The latter is my next port of call.

I did notice when I turned my son's tablet back on that for a period of a few minutes it was charging and pulling 1.10A before dropping back to 0.81A. Is this the kernel causing this...?

My mother in law's nexus does the same thing. It has same firmware and kernel. I have used this firmware/Kernel combo many times. It does not always result in a slow charging tablet. Maybe this is hardware version related.

I'll let you know when I've had a chance to investigate further. Sorry for the long winded post. Just brain dumping. Feel free to suggest anything. We gotta sort this out once and for all even if it's to say "sod it, I can't do anything else"

Thanks.

Sent from my SM-G850F using Tapatalk
 
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mr.crabs!

Member
Aug 19, 2012
28
5
I am happy to report that my son's tablet is now charging just about as good as my own. I haven't had to play with the firmware/Kernel at all. It would seem that cleaning all the contact areas I have mentioned above has resolved the problem in my instance.

I did notice that it seemed to charge more as expected following a complete discharge followed by full charge.

I am going to see if my mother in law's nexus 7 can be sorted in the same way and let you know.

Sent from my SM-G850F using Tapatalk
 

sthpaw01

Senior Member
Sep 23, 2012
159
24
I am happy to report that my son's tablet is now charging just about as good as my own. I haven't had to play with the firmware/Kernel at all. It would seem that cleaning all the contact areas I have mentioned above has resolved the problem in my instance.

I did notice that it seemed to charge more as expected following a complete discharge followed by full charge.

I am going to see if my mother in law's nexus 7 can be sorted in the same way and let you know.

Sent from my SM-G850F using Tapatalk
Pics of what you cleaned please! I have a new battery arriving today. I haven't used my N7 in few months and it will not charge so I'm replacing the battery first. Knowing what I could clean inside the unit while im inside of it would help me out.

Sent from my XT1096 using Tapatalk
 

mr.crabs!

Member
Aug 19, 2012
28
5
Pics of what you cleaned please! I have a new battery arriving today. I haven't used my N7 in few months and it will not charge so I'm replacing the battery first. Knowing what I could clean inside the unit while im inside of it would help me out.

Sent from my XT1096 using Tapatalk
If your nexus is not charging at all then I would first try leaving it on charge for an hour to see if it is just very drained. Check your charger works with another device. Check these things also:

》check your nexus is not in APX mode. You can check this by plugging it into your pc and checking under hardware devices under control panel on your pc to look for APX device. If it is, then your nexus is knackered and there is currently no fix (unless you have created 'blobs' for your device previously. This is a whole other topic which you can read about). All you can do now is replace the motherboard.

》check usb port is not damaged. This is the most likely probability. You can buy them quite cheaply now on ebay and they are quite easy to replace.

Sadly, I would be surprised if your battery is completely duff, just don't see that very often with these. If it does solve the problem then try putting your old battery back in and try charging it again for interests sake.

I will try and get some pictures posted for those who need some reference, but really it is quite self explanatory when you look inside your tab.

Sent from my SM-G850F using Tapatalk

---------- Post added at 06:15 PM ---------- Previous post was at 06:14 PM ----------

Which part of ur nexus 7 u have cleaned plz tell me

Sent from my Nexus 7 using Tapatalk 2
Check my post above. All written there.

Sent from my SM-G850F using Tapatalk
 
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  • 11
    Solved! (at least for me)

    I suspected this was hardware for a while since this issue would happen no matter what ROM was on there and no matter how many times I did a factory reset. Knowing that I'm just out of warranty and that Asus would probably charge me a hefty fee for fix it, I figured I had nothing to lose. Read my own thread on the issue to see what troubleshooting steps I had already tried here: http://forum.xda-developers.com/showthread.php?t=2390222

    Anyway, I took the back off and then removed the battery (the connection was fine btw). I removed the three screws that held the speakers in place. Then, suspecting that the small connections might need to be rewet, I plugged in my soldering iron and rewet the following areas in black (image borrowed from iAppleDev as I forgot to take my own) :



    For insurance, I also folded up a small piece of paper and placed it where the blue box is. Screwing the speakers back in place held the paper in place and held the ribbon cable retainer clip against the connectors, giving a stronger connection.

    I turned off my Nexus 7 with a 9% battery and then when to take care of other things. Came back in an hour or so (probably less) and I see that the battery is already at 33%! This is with the Asus charger plugged in, which wasn't working at all previously.

    Very stoked. Kinda bummed I didn't figure this out before a conference I had to go to last week. Would have been nice to read on my Nexus 7 instead of my phone.
    5
    I have a little insight to share on this topic that might apply to some of you.

    I bought mine back in december from costco and had no issues up until last night.

    Up until then it had been sitting on its official charging dock by asus underneath my TV plugged to a big UPS along with my TV and amp.
    Last night I decided to move it into my bedroom cause I wanted to start using it as a clock and to listen to music or podcasts before sleeping and to wake me up. Even before I got the dock the OEM charger was always done within 2.5 hours at most from a very low state like under 10% cause I was using the hell out of it back then.

    I had to do 2 things in order for this to be practical for me.

    1. The damn usb cable they give you is so short you couldn't hang a mouse with it so I changed it for one twice as long.

    2. I plugged the OEM charger and dock to a APC Surge Arrest, Not a piece of crap power bar (or so I thought).

    And here is what happened.
    I went to bed with the battery at about 22% and when I woke 8 hours later the battery had only managed to get up to 57% which is unacceptable.

    I then did 1 thing I unplugged it from the APC Surge Arrest (POS power bar that I might soon throw in the trash!) and straight to a wall outlet. I did not shut it off simply put it on sleep/standby instead of letting it be daydream clock.

    Then I came here and read this thread, I at first had the suspicion that maybe it was the USB cable I switched but after reading somebody's comment about polarity I thought perhaps I was a tired last night and plugged it in the wrong way. It's pretty easy to do that actually and its still a possibility that it was plugged to the APC the wrong way.

    After reading all the comments here and getting a coffee, Which maybe took me 10-15 minutes at most I went back to check on it.
    At this point it was already at 60%. Then instead of putting it to sleep I just let it as I normally would on Daydream clock and by the time I finished typing this message it was at 65%. This fast charge is normal for the dock.

    So problem is solved here it was the power brick that it was plugged to or possibly the polarity. I am going to know today if that is the case because I have a Nexus 10 charger that I also plugged into that same power bar last night so next time it needs a recharge I will keep an eye on its progress. If the Nexus 10 charges up fine then either the ASUS charger does not like the APC Surge Arrest or it was plugged the wrong way or the outlet on the APC that I used was bad or something and if its the latter that thing is still going into the trash.

    For those plugged with the charger straight to the wall I would recommend the following.

    A. Make sure its plugged in the right way or just reverse however its plugged in now.

    B. Try another outlet and if that's also slow maybe have them tested with a tester or looked at by a electrician.

    But if you are plugging them into some kind of power bar / surge protector then do try them directly to the wall and see if that helps.

    90% of the homes I had lived in have had crap power installations, Way too many outlets on the same breaker or missing grounds so on which is why I always end up redoing them or installing separate outlets on their own breakers for my gear like my PC's and TV's.

    Just my 2 cents. I went from terrible charging rates like those describes 3% per hour up to how it should be so hope this helps some of you.

    Having to RMA my n7 would have been a real bummer. Especially if it would have been for nothing.

    To add one last thing to my long winded post. Don't even bother trying to charge it via any kind of USB port on your computer its so slow you might as well have it on a hamster wheel with a dynamo. You really do need a real charger or the wait is unbearable.
    5
    Guys.... i have a friend from asus who told me that if you have slow charging problem you gotta do this.


    use the stock asus usb cable
    plug it in to your computer and make sure it's charging via USB, then just wait for 3 minutes then
    unplug it, charge/plug it in via AC using stock asus 2A charger. then wait for atleast 5-8 mins
    then check it if it's starts to charge quickly. =)

    Hit thanks if it's working.
    3
    Much as I love my Apple products the way the company chooses to ignore existing standards and invent their own is frustrating. Relating to this thread this has lead to 2 standards for power supplies (chargers): the Apple standard and the USB standard defined in the USB 2 (and later) specifications. Originally the Nexus 7 used the USB spec of shorted data wires to decide if it should attempt to draw more than the spec 500ma a USB device is allowed to draw when connected to a computer. As of the update to Android 4.2 Google added smarts to the charging code in an effort to get the tablet to draw high power charging current from a charger using either standard. I'm convinced that this results in the tablet getting confused and chooses to only draw current at the lower 500ma rate. Perhaps the brand of cable results in electrical noise on the data lines which fools the tablet into thinking that there's a data connection. Regardless of what happens, plugging it into your computer will make a real data connection. Then moving to the charger will make a charge style connection and since it happens immediately after a real data connection the tablet has no problem deciding to shift to a high power current draw.

    Sent from my Nexus 7 using Xparent Purple Tapatalk 2
    2
    guys i made a video on how to fix slow charging issue of your Nexus 7. i hope it helps.

    http://www.youtube.com/watch?v=bZFcfirYvuA