Database Users

[Q] Battery Charging - Current Draw When Complete

Guys, I'm hoping someone familiar with LiPo battery charging can give me some insight. I've done some diagnostics, and I'd like your take...
- Nexus 7 3G, purchased a few weeks ago. 4.2.1, not rooted, stock charger and cable
- Battery life seems good, fully charges and discharges 'normally'
- I usually charge with the device powered off (ie: blocky battery icon in the middle of the screen).
However....
- On two occasions now, I've left it on the charger for a long time (>15 hours) and have come back to a dead device.
- Pressing the power button doesn't bring up the blocky battery icon.
- Holding the power button for 30+ seconds brings the device back back.
- It has otherwise never failed to boot properly during normal use.
Out of curiosity, I was wondering if there was something wrong with the charging process causing this, so
- I plugged the stock charger into my Kill-A-Watt last night to monitor the charging current.
- Even 8 hours after the device finished charging (via the blocky icon), the current never dropped to zero - it stuck around 10mA on the AC side (ie: ~1.2W).
- My first N7 (sent back for a bad speaker and dead pixels) went to zero after charging. My iPad does the same.
QUESTION(S):
I know modern LiPo batteries have internal circuitry to prevent overcharging, but does it sound like that circuitry might be defective on mine such that I should be worried about overcharging? Could that be the reason for my lockups?
I really don't want to go through the return process again if I don't have to. I'd rather just live with it if I can prevent damage by taking it off the charger when complete. Thoughts? Opinions? Have any of you done this test, and if so, does yours go to zero?
Thanks for any insight!

developer_john said:
However....
- On two occasions now, I've left it on the charger for a long time (>15 hours) and have come back to a dead device.
- Pressing the power button doesn't bring up the blocky battery icon.
- Holding the power button for 30+ seconds brings the device back back.
- It has otherwise never failed to boot properly during normal use.
Click to expand...
Click to collapse
That might be a possible cause... Leaving any device plugged in the charger for long periods of time is not recommended. Anyway have you tried charging the tablet with another charger with a higher output? If it refuses to turn on even after holding the power button for 30 seconds you might be able to "wake" it up by using a higher output charger. Thats what I did on my Nexus 7 when the battery level went too low.

cr0wnest said:
That might be a possible cause... Leaving any device plugged in the charger for long periods of time is not recommended. Anyway have you tried charging the tablet with another charger with a higher output? If it refuses to turn on even after holding the power button for 30 seconds you might be able to "wake" it up by using a higher output charger. Thats what I did on my Nexus 7 when the battery level went too low.
Click to expand...
Click to collapse
Hmmm...everything I've read has indicated that Lithium Ion/Polymer batteries can be left on a charger without damage since they have internal circuitry to prevent overcharging (although I realize a constant topping off is probably not wise in the long run). As for a charger with a higher output, I thought the stock charger was 2.1A....I've never heard of a 3A or 4A USB charger. Can you clarify what you mean?
Also, as I said, on the two occasions it has locked up, holding the power button has brought it back, so I'm not really asking about how to get it back if it locks up - I'm asking if the behavior (locking up, charge current not dropping to 0) is indicative of a battery that has faulty overcharge protection.
Thanks though!

The "charger" IC inside the N7 not only charges the battery but at the same time powers the device - it should allow use of a N7 with no or a faulty battery. I've never looked at the standby settings on the N7 but I would suggest that is where your 1W is going. The only info about the IC I know is http://www.summitmicro.com/prod_select/summary/SMB347/SMB347.htm
Added I think this is an identical TI version of the chip http://www.ti.com/lit/ds/slusaw5a/slusaw5a.pdf

peterk-1 said:
The "charger" IC inside the N7 not only charges the battery but at the same time powers the device - it should allow use of a N7 with no or a faulty battery. I've never looked at the standby settings on the N7 but I would suggest that is where your 1W is going. The only info about the IC I know is http://www.summitmicro.com/prod_select/summary/SMB347/SMB347.htm
Added I think this is an identical TI version of the chip http://www.ti.com/lit/ds/slusaw5a/slusaw5a.pdf
Click to expand...
Click to collapse
Thanks - that's good info. However, since I have been charging with the device off, it would seem to me that it shouldn't be drawing any standby current...unless just the act of charging puts the unit in a form of standby. It also still doesn't explain why my first unit went to 0A a while after charging completed, while this one doesn't. I'm now wondering if I may be looking at roundoff error. The resolution of the kill-a-watt is .01A - which is what I'm seeing. It could just be that both units drew some current after charge completion, but this one pulls marginally more.
So, my question still stands. Does anyone familiar with LiPo technology know if this sounds like my overcharge protection circuitry is faulty? Is it normal for a device that has completed charging to draw SOME current, and if so, how much? Would someone else with a Kill-A-Watt be willing to try this and let me know what you see?
Thanks again for the help guys...

Just in case anyone is still following this thread, I have some new info. I charged my N7 last night POWERED ON.....and after charging was complete, the AC current draw went to 0A. I'm starting to wonder now whether the 1.2W constant power I saw when charging powered off is the power needed to keep the charging circuitry alive while the tablet is powered off. When the device is powered on, maybe this circuitry is running off the battery allowing the AC draw to go to 0A. I have absolutely nothing to support this, so it's just a guess/hypothesis, but at least I know my N7 is behaving the same as my first one. I also loaded Simple Battery Logger while doing my last charge and all looks normal....it charged up to about 4.208V, indicated 'full', then the voltage start dropping off - which tells me that it stopped charging. It also maintained a temp of about 23C throughout the process. I'm running a battery test right now and it doesn't seem to have been damaged by my overnight charging episodes...if anything, the battery life is better than when I first got it.
I'm going to let it go here and assume all is well. If anyone does any experiments with theirs, I'd be interested in seeing the results.
Thanks again!

[Q] Strange Battery/Charging Issue

EDIT: My model is I9505
Whilst on holidays, I took my phone out of my bag (when I knew it was getting close to flat) to find it not turning on. I assumed the battery was dead, but when I plugged it into the charger it didn't charge. I fiddled around a bit, and eventually got the vibration and charging light - but it kept turning off before the green battery came on saying charging. Being on holidays I didn't have my USB jig, or even external battery charger with me. I assumed it was a loose connection with the charging port - as every time I tried to plug it into charge it would only sporadically say that it was charging - but never get past the picture of the battery and the swirling icon (prior to the green battery coming up).
Upon arriving home, I got out my external charger, took out the battery, charged it for a few hours, then tried it. Again - it wouldn't turn on.
I then tried plugging the phone in again - but to the 800mA charging doc micro USB, insteead of the standard 2 amp. Straight away I get the charging picture, and the little graphic showing me the phone is about 1% charged. I leave it, the screen goes off. I come back 15mins later, the phone is RIDICULOUSLY hot, and the screen off. I unplug and replug to find the battery is still at about the same 1% level. I turn the phone on - it boots, shows 1/2% and then turns off as soon as I unplug it from the dock - even if I plug it straight into a 2 amp charger. I now decide that maybe the battery itself is the issue - and it's not holding charge. So I whiz out and buy two replacement batteries (MPJ ones, as they were fairly cheap - and this was just for the sake of finding the issue).
I charge one for about an hour on the external charger (the phone didn't turn on when I put the battery straight in). Then put it in - same deal. Nothing. I plug it into the dock micro-USB out to charge - again it comes up as charging, and shows at about 1%. I turn it on, and again am shown 1/2% charge, and again as soon as I unplug from the micro USB dock it turns itself off.
It is almost as if the phone isn't taking any power from batteries, and only direct from the power outlet itself. I'm unsure what could possibly have caused this. I can only think it may have been an external battery which I was using for a while on holidays (which had a 1amp micro USB out, that I was using to try and keep my phone charged). That is the only thing I have done different over this period (at least as far as I can recall!)
So basically - in short:
i) Phone won't turn on unless plugged in to a low amp charger (Computer USB, dock micro USB out etc)
ii) Even after charging batteries in external charger (two different external chargers have been tried) the phone is showing 1/2% battery
iii) The phone turns off a few seconds after I unplug it from the power source.
Any ideas!? I will take the phone to get repaired after Christmas (if they still repair it, as it's running a custom ROM).
BTW. a USB jig worked for the first time this afternoon - when I tried it not long after taking the phone off the dock. It's also worth noting that the phone is ridiculously hot when on the dock (around the camera/sim/micro SD area).

Googling there seem to be a few in similar situations.
This YouTube shows it
http://www.youtube.com/watch?v=U5B2By7fGII
Sent from my R821 using Tapatalk

abbaskip said:
Googling there seem to be a few in similar situations.
This YouTube shows it
http://www.youtube.com/watch?v=U5B2By7fGII
Sent from my R821 using Tapatalk
Click to expand...
Click to collapse
did you even try with a spare battery? can you check if your battery swollen? it might be the battery's fault

Repulsa said:
did you even try with a spare battery? can you check if your battery swollen? it might be the battery's fault
Click to expand...
Click to collapse
Hi, thanks for the response.
As mentioned in my first post, battery was what I thought was the issue at one stage, but I've tried two other batteries too. The original battery isn't swollen, but in any case I'm having the same issue with the other batteries.
I've tried charging them all on external charger before using them in the phone, and I get the same issues regardless of what I do.
It just seems strange that the phone switches on (now showing 0%) when plugged in, but not when unplugged.
And the batteries aren't being read properly, as they show 0% regardless of how long I pre-charge for.

Experimenting tonight, I've found that if I try to boot into recovery - even when plugged into dock, it dies before it even gets into recover.
Yet, if I boot the phone, I get to the main Android launcher/lockscreen before it dies...
Really has me baffled.

abbaskip said:
Experimenting tonight, I've found that if I try to boot into recovery - even when plugged into dock, it dies before it even gets into recover.
Yet, if I boot the phone, I get to the main Android launcher/lockscreen before it dies...
Really has me baffled.
Click to expand...
Click to collapse
Hello again, if you have any spare battery and its has 50 or 100% try to reflash the rom just to see the results. or try a different chargers and cables as well, If it all fails, i think you should send it to Samsung for the warranty. Software problems are somewhat easier to fix here than hardware, so your best option is to let Samsung handle it.

Repulsa said:
Hello again, if you have any spare battery and its has 50 or 100% try to reflash the rom just to see the results. or try a different chargers and cables as well, If it all fails, i think you should send it to Samsung for the warranty. Software problems are somewhat easier to fix here than hardware, so your best option is to let Samsung handle it.
Click to expand...
Click to collapse
Thanks again for your response, but you're clearly not reading what my issue is before making suggestions. As I have now said twice - I have tried three batteries, and batteries that I have charged for hours on an external charger before using. But they still come up at 0%. Not sure how you imagine I flash a ROM
It may be a matter of taking it to my dealer it seems. If anyone else has suggestions before I get to that (after Christmas) it'd be much appreciated

The batteries fully charged on external chargers and I'm still getting the same issues.
I'm hoping it's not kernel related. Can anyone confirm that if it makes it to download mode Werth a jig (but turns off after a few seconds) that this would be a hardware issue? It only turns on with the jig when it's straight off the charger though - so seems it's still not using the battery for power, almost residual power somewhere.
Sent from my R821 using Tapatalk

abbaskip said:
EDIT: My model is I9505
Whilst on holidays, I took my phone out of my bag (when I knew it was getting close to flat) to find it not turning on. I assumed the battery was dead, but when I plugged it into the charger it didn't charge. I fiddled around a bit, and eventually got the vibration and charging light - but it kept turning off before the green battery came on saying charging. Being on holidays I didn't have my USB jig, or even external battery charger with me. I assumed it was a loose connection with the charging port - as every time I tried to plug it into charge it would only sporadically say that it was charging - but never get past the picture of the battery and the swirling icon (prior to the green battery coming up).
Upon arriving home, I got out my external charger, took out the battery, charged it for a few hours, then tried it. Again - it wouldn't turn on.
I then tried plugging the phone in again - but to the 800mA charging doc micro USB, insteead of the standard 2 amp. Straight away I get the charging picture, and the little graphic showing me the phone is about 1% charged. I leave it, the screen goes off. I come back 15mins later, the phone is RIDICULOUSLY hot, and the screen off. I unplug and replug to find the battery is still at about the same 1% level. I turn the phone on - it boots, shows 1/2% and then turns off as soon as I unplug it from the dock - even if I plug it straight into a 2 amp charger. I now decide that maybe the battery itself is the issue - and it's not holding charge. So I whiz out and buy two replacement batteries (MPJ ones, as they were fairly cheap - and this was just for the sake of finding the issue).
I charge one for about an hour on the external charger (the phone didn't turn on when I put the battery straight in). Then put it in - same deal. Nothing. I plug it into the dock micro-USB out to charge - again it comes up as charging, and shows at about 1%. I turn it on, and again am shown 1/2% charge, and again as soon as I unplug from the micro USB dock it turns itself off.
It is almost as if the phone isn't taking any power from batteries, and only direct from the power outlet itself. I'm unsure what could possibly have caused this. I can only think it may have been an external battery which I was using for a while on holidays (which had a 1amp micro USB out, that I was using to try and keep my phone charged). That is the only thing I have done different over this period (at least as far as I can recall!)
So basically - in short:
i) Phone won't turn on unless plugged in to a low amp charger (Computer USB, dock micro USB out etc)
ii) Even after charging batteries in external charger (two different external chargers have been tried) the phone is showing 1/2% battery
iii) The phone turns off a few seconds after I unplug it from the power source.
Any ideas!? I will take the phone to get repaired after Christmas (if they still repair it, as it's running a custom ROM).
BTW. a USB jig worked for the first time this afternoon - when I tried it not long after taking the phone off the dock. It's also worth noting that the phone is ridiculously hot when on the dock (around the camera/sim/micro SD area).
Click to expand...
Click to collapse
In my view its a fault of charging IC . Since you have tried with replacing battery.

nishangrg said:
In my view its a fault of charging IC . Since you have tried with replacing battery.
Click to expand...
Click to collapse
Sorry, what is charging IC? If it was a charging fault, a fully charged battery would work wouldn't it?

So I took my phone to my SP - Telstra. The phone, being only about 6 months old, was still within warranty period. Not surprisingly, Telstra have said that as there is a Custom ROM on the phone, the warranty is voided. I stated that my understanding is that under Australian law, as it is a hardware fault, and not a fault caused by the ROM, the warranty still stands - however Telstra wouldn't budge and said I have 5 days to decide if I want to pay the $300+ for the repair.
What is my next course of action? Has anybody had a similar issue previously? Is the TIO the next port of call? Or should I be going to NSW Department of Fair Trading?
I'm sure I've read previously that phones are still covered under warranty after rooting etc, if it can be shown that it's a hardware fault, not a software fault. As the battery doesn't seem to be powering the phone, this clearly seems to be the case - esp. as it is the same in download mode and recovery mode.
Any help would be great. Please don't post pointing out that I rooted my phone so THAT's my own fault etc. These posts aren't helpful, I already have know that.

So I took my phone to my SP - Telstra. The phone, being only about 6 months old, was still within warranty period. Not surprisingly, Telstra have said that as there is a Custom ROM on the phone, the warranty is voided. I stated that my understanding is that under Australian law, as it is a hardware fault, and not a fault caused by the ROM, the warranty still stands - however Telstra wouldn't budge and said I have 5 days to decide if I want to pay the $300+ for the repair.
What is my next course of action? Has anybody had a similar issue previously? Is the TIO the next port of call? Or should I be going to NSW Department of Fair Trading?
I'm sure I've read previously that phones are still covered under warranty after rooting etc, if it can be shown that it's a hardware fault, not a software fault. As the battery doesn't seem to be powering the phone, this clearly seems to be the case - esp. as it is the same in download mode and recovery mode.
Any help would be great. Please don't post pointing out that I rooted my phone so THAT's my own fault etc. These posts aren't helpful, I already have know that.

NEXUS 7 slow charging problem solved?

Last week, I found that my nexus 7 (16g wifi only) start to charge really slow or even not charging. This happen after I upgrade my tablet to android 4.4.2(no root, no mod). I tried all the ways I could found on internet such as disconnect the battery and reconnect after few minutes, downgrade to android 4.3 or 4.2, changing to different type of charger and so on but failed.
After tried for few days, I was frustrated and decided to throw away the tablet. But 2 days ago, when I tried to charge the tablet with samsung galaxy tab2 7.0 charger, I manage to charge from 0% to 50% in two hour. I thought my tablet was back to alive but the tablet stop charging after 50% battery. I tried with oem 2A charger or cheapo china ipad charger and the charging starts but slow and sometimes not charging. I search online and found out that the samsung tab2 7.0 charger has 1.2V at both data pins and both data pins was shorted. I checked my asus oem charger and found out that both data pin was shorted but no voltage supplied.
I take a usb cable, strip and cut both data wire and short both data wire at micro usb side. I connect the tablet to the samsung charger and the tablet start charging and charge at normal speed to 100%. I thought that was the solution but yesterday, when I tried to charge the tablet which has 10% battery remains with samsung charger and my modified usb cable, the tablet charge, but in slow rate. I take half a day to charge to 50%. i exchange the moded usb cable with a normal usb cable and this time the tablet charge to around 80% in one hour. I was confused. Does my tablet need voltage of 1.2V at both data pins for the tablet to recognize as normal charger?
I start to do my experiment by using the oem charger. I apply around 1.2V by using resistors connect to the +5v and gnd. My tablet start to charge at normal rate that i can get the increment in battery % after 1 or 2 minutes in screen off mode. After charge to around 25% my tablet stop charging. I checked the data pins voltage and found out to be around 1.8V. 1.8V??? not 1.2V??? I check the resistors connection and disconnect my tablet from the usb cable. The data pins is now 1.2V. I connect my tablet back to the usb cable, wait for the tablet to start charging at normal rate and disconnect the data wires from the resistor. I tested with multimeter and found out that there was a voltage of 3.1V at data pins (shorted together) from the tablet when charging.
After a few tries by changing the resistors with different values to increase or decrease the data pins voltage, I manage to get a combinations that works well with my charger and my tablet charge normally. With the resistor combination, I get a voltage of 0.5V when no tablet connected and around 1.2V when tablet connected and start charging by using a resistor of 1Kohm connect from the +5V pin to the data pin and 100ohm connect from the data pin to the ground. Actually my tablet shows sign of normal charging when I apply 1V to 1.5V to the data pins that I choose 1.2V for full charging testing. I manage to charge my tablet from 0% to around 30% by using the samsung charger, 30% to 60% using the cheap ipad charger and 60% to 100% using the oem charger. No sign of stop charging or slow charging during the charging process. Maybe this is the solution to the charging problem?
I hope that someone which is more professional in this fields will try my way and give me the final results of the most suitable resistor combination or is my way of solution, or is this just an coincidence or my solution can only be applied onto my tablet? Warning: Try at your own risk.

fix foe nexus 7 slow charging
samuraiman said:
Last week, I found that my nexus 7 (16g wifi only) start to charge really slow or even not charging. This happen after I upgrade my tablet to android 4.4.2(no root, no mod). I tried all the ways I could found on internet such as disconnect the battery and reconnect after few minutes, downgrade to android 4.3 or 4.2, changing to different type of charger and so on but failed.
After tried for few days, I was frustrated and decided to throw away the tablet. But 2 days ago, when I tried to charge the tablet with samsung galaxy tab2 7.0 charger, I manage to charge from 0% to 50% in two hour. I thought my tablet was back to alive but the tablet stop charging after 50% battery. I tried with oem 2A charger or cheapo china ipad charger and the charging starts but slow and sometimes not charging. I search online and found out that the samsung tab2 7.0 charger has 1.2V at both data pins and both data pins was shorted. I checked my asus oem charger and found out that both data pin was shorted but no voltage supplied.
I take a usb cable, strip and cut both data wire and short both data wire at micro usb side. I connect the tablet to the samsung charger and the tablet start charging and charge at normal speed to 100%. I thought that was the solution but yesterday, when I tried to charge the tablet which has 10% battery remains with samsung charger and my modified usb cable, the tablet charge, but in slow rate. I take half a day to charge to 50%. i exchange the moded usb cable with a normal usb cable and this time the tablet charge to around 80% in one hour. I was confused. Does my tablet need voltage of 1.2V at both data pins for the tablet to recognize as normal charger?
I start to do my experiment by using the oem charger. I apply around 1.2V by using resistors connect to the +5v and gnd. My tablet start to charge at normal rate that i can get the increment in battery % after 1 or 2 minutes in screen off mode. After charge to around 25% my tablet stop charging. I checked the data pins voltage and found out to be around 1.8V. 1.8V??? not 1.2V??? I check the resistors connection and disconnect my tablet from the usb cable. The data pins is now 1.2V. I connect my tablet back to the usb cable, wait for the tablet to start charging at normal rate and disconnect the data wires from the resistor. I tested with multimeter and found out that there was a voltage of 3.1V at data pins (shorted together) from the tablet when charging.
After a few tries by changing the resistors with different values to increase or decrease the data pins voltage, I manage to get a combinations that works well with my charger and my tablet charge normally. With the resistor combination, I get a voltage of 0.5V when no tablet connected and around 1.2V when tablet connected and start charging by using a resistor of 1Kohm connect from the +5V pin to the data pin and 100ohm connect from the data pin to the ground. Actually my tablet shows sign of normal charging when I apply 1V to 1.5V to the data pins that I choose 1.2V for full charging testing. I manage to charge my tablet from 0% to around 30% by using the samsung charger, 30% to 60% using the cheap ipad charger and 60% to 100% using the oem charger. No sign of stop charging or slow charging during the charging process. Maybe this is the solution to the charging problem?
I hope that someone which is more professional in this fields will try my way and give me the final results of the most suitable resistor combination or is my way of solution, or is this just an coincidence or my solution can only be applied onto my tablet? Warning: Try at your own risk.
Click to expand...
Click to collapse
here's what i posted at google forums. hope it helps you
FIXED!!!
and i didnt wait for google to solve it. they take ages.
as one of the pioneers of this thread, trust me i have tried everything, and started solutions you can see if you back track a bit.
what does not work/or temporary works but not permanent:
>OS downgrading
>bootloader upgrading
>plug unplug with battery monitor (temporary)
>reseating battery cable
>changing chargers/cables/using OEM
>all else above
what works:
>dock
from what i observe, some symptoms of failure started prior to kitkat, as to some of the nexus' handled to me. and some kitkat dont have it.
and the dock works. led me to conclude it might be hardware, probably with the USB
THE FIX:
OPEN YOUR NEXUS 7 AND RESEAT THE USB CHARGING PORT FROM THE INSIDE. if you do not know how, this video will guide you:
(cannot post link) go to youtube and watch?v=m5FagzLdbbM
as you can see the 4:07 in the video is the most important, remove the usb port/audio port completely and reseat it, place it back tightly.
my tab was left at 0% charge, unable to charge anymore, so i was left with the option to tinker it. which to my delight, it charges now at 500-900mah. i tried to drain it and charge again charging-recharging 3 times before posting it here to make sure it was not sheer luck, and so it did.
its a hardware problem guys. i just wish google/asus had the courage to admit it rather than we find it ourselves. go ahead try it. post if it works
for you. it worked for me.

emanlee said:
here's what i posted at google forums. hope it helps you
FIXED!!!
and i didnt wait for google to solve it. they take ages.
as one of the pioneers of this thread, trust me i have tried everything, and started solutions you can see if you back track a bit.
what does not work/or temporary works but not permanent:
>OS downgrading
>bootloader upgrading
>plug unplug with battery monitor (temporary)
>reseating battery cable
>changing chargers/cables/using OEM
>all else above
what works:
>dock
from what i observe, some symptoms of failure started prior to kitkat, as to some of the nexus' handled to me. and some kitkat dont have it.
and the dock works. led me to conclude it might be hardware, probably with the USB
THE FIX:
OPEN YOUR NEXUS 7 AND RESEAT THE USB CHARGING PORT FROM THE INSIDE. if you do not know how, this video will guide you:
(cannot post link) go to youtube and watch?v=m5FagzLdbbM
as you can see the 4:07 in the video is the most important, remove the usb port/audio port completely and reseat it, place it back tightly.
my tab was left at 0% charge, unable to charge anymore, so i was left with the option to tinker it. which to my delight, it charges now at 500-900mah. i tried to drain it and charge again charging-recharging 3 times before posting it here to make sure it was not sheer luck, and so it did.
its a hardware problem guys. i just wish google/asus had the courage to admit it rather than we find it ourselves. go ahead try it. post if it works
for you. it worked for me.
Click to expand...
Click to collapse
thx mate .. how do you know what the actual charge rate is? on my Galaxy S3 there is an app for that, but can't find anything that works on this unit. thx

jj92942000 said:
thx mate .. how do you know what the actual charge rate is? on my Galaxy S3 there is an app for that, but can't find anything that works on this unit. thx
Click to expand...
Click to collapse
https://play.google.com/store/apps/details?id=ccc71.bmw

Nexus 7 slow charging problem
Thanks emanlee, worked for me. I thought my battery was weak. Made my day.
emanlee said:
here's what i posted at google forums. hope it helps you
FIXED!!!
and i didnt wait for google to solve it. they take ages.
as one of the pioneers of this thread, trust me i have tried everything, and started solutions you can see if you back track a bit.
what does not work/or temporary works but not permanent:
>OS downgrading
>bootloader upgrading
>plug unplug with battery monitor (temporary)
>reseating battery cable
>changing chargers/cables/using OEM
>all else above
what works:
>dock
from what i observe, some symptoms of failure started prior to kitkat, as to some of the nexus' handled to me. and some kitkat dont have it.
and the dock works. led me to conclude it might be hardware, probably with the USB
THE FIX:
OPEN YOUR NEXUS 7 AND RESEAT THE USB CHARGING PORT FROM THE INSIDE. if you do not know how, this video will guide you:
(cannot post link) go to youtube and watch?v=m5FagzLdbbM
as you can see the 4:07 in the video is the most important, remove the usb port/audio port completely and reseat it, place it back tightly.
my tab was left at 0% charge, unable to charge anymore, so i was left with the option to tinker it. which to my delight, it charges now at 500-900mah. i tried to drain it and charge again charging-recharging 3 times before posting it here to make sure it was not sheer luck, and so it did.
its a hardware problem guys. i just wish google/asus had the courage to admit it rather than we find it ourselves. go ahead try it. post if it works
for you. it worked for me.
Click to expand...
Click to collapse

emanlee said:
here's what i posted at google forums. hope it helps you
FIXED!!!
and i didnt wait for google to solve it. they take ages.
as one of the pioneers of this thread, trust me i have tried everything, and started solutions you can see if you back track a bit.
what does not work/or temporary works but not permanent:
>OS downgrading
>bootloader upgrading
>plug unplug with battery monitor (temporary)
>reseating battery cable
>changing chargers/cables/using OEM
>all else above
what works:
>dock
from what i observe, some symptoms of failure started prior to kitkat, as to some of the nexus' handled to me. and some kitkat dont have it.
and the dock works. led me to conclude it might be hardware, probably with the USB
THE FIX:
OPEN YOUR NEXUS 7 AND RESEAT THE USB CHARGING PORT FROM THE INSIDE. if you do not know how, this video will guide you:
(cannot post link) go to youtube and watch?v=m5FagzLdbbM
as you can see the 4:07 in the video is the most important, remove the usb port/audio port completely and reseat it, place it back tightly.
my tab was left at 0% charge, unable to charge anymore, so i was left with the option to tinker it. which to my delight, it charges now at 500-900mah. i tried to drain it and charge again charging-recharging 3 times before posting it here to make sure it was not sheer luck, and so it did.
its a hardware problem guys. i just wish google/asus had the courage to admit it rather than we find it ourselves. go ahead try it. post if it works
for you. it worked for me.
Click to expand...
Click to collapse
I have an old Nexus 7 and was about to toss it out because it wouldn't charge, this took 20 minutes and now it charges as it did when new - great.
Thanks.

emanlee said:
fix foe nexus 7 slow charging
here's what i posted at google forums. hope it helps you
FIXED!!!
and i didnt wait for google to solve it. they take ages.
as one of the pioneers of this thread, trust me i have tried everything, and started solutions you can see if you back track a bit.
what does not work/or temporary works but not permanent:
>OS downgrading
>bootloader upgrading
>plug unplug with battery monitor (temporary)
>reseating battery cable
>changing chargers/cables/using OEM
>all else above
what works:
>dock
from what i observe, some symptoms of failure started prior to kitkat, as to some of the nexus' handled to me. and some kitkat dont have it.
and the dock works. led me to conclude it might be hardware, probably with the USB
THE FIX:
OPEN YOUR NEXUS 7 AND RESEAT THE USB CHARGING PORT FROM THE INSIDE. if you do not know how, this video will guide you:
(cannot post link) go to youtube and watch?v=m5FagzLdbbM
as you can see the 4:07 in the video is the most important, remove the usb port/audio port completely and reseat it, place it back tightly.
my tab was left at 0% charge, unable to charge anymore, so i was left with the option to tinker it. which to my delight, it charges now at 500-900mah. i tried to drain it and charge again charging-recharging 3 times before posting it here to make sure it was not sheer luck, and so it did.
its a hardware problem guys. i just wish google/asus had the courage to admit it rather than we find it ourselves. go ahead try it. post if it works
for you. it worked for me.
Click to expand...
Click to collapse
Thank you very much, it has also fixed the issue to me. The tablet is not ready yet to become e-waste. Genius!

Yotaphone 2 not charging

Hi all,
Since the Lollipop update my battery life has been pretty terrible, and the device seems to have run much hotter than previously. The battery hit about 16% by 5pm today, so I plugged it in as normal, just as the update claiming to improve standby battery usage popped up, but the phone wouldn't acknowledge the cable being connected. I've tried different cables, different plugs, tried connecting it to my PC etc and nothing. The battery hit 1% and the phone switched off and is now dead.
Since the battery is not removable, I guess a warranty replacement/repair is my only option at this point, with all my stuff lost.
Anyone got any bright ideas?

Try the new update
Sent from my YD201 using Tapatalk

adamo86 said:
Try the new update
Sent from my YD201 using Tapatalk
Click to expand...
Click to collapse
I can't, the device is dead!

The only solution I see is contact mother Russia and ask for support or a replacement.
Sent from my YD201 using XDA Free mobile app

You could flash the latest update via download mode (which would save you from the power hog that is Lollipop), but if the device outright refuses to charge, even from the wall outlet which gives you more power than USB, then you are out of luck.

It's always possible that the phone has been somehow damaged, but I do not necessarily believe that.
TLDR: see at bottom of post...
Since the (initial) Lollipop update, I've had pretty terrible battery life, too. I do happen to have a couple of games that exert a great toll on battery life, and what's strange is that I remember, in the pre-Lollipop days, being able to run the game on my Yotaphone plugged to a USB charger and have the bettery recharge, slowly but steadily. Since the update, I've noticed that the phone, plugged to the very same USB charger, would continue to drain the battery instead of charging while I played the game.
The funny thing is that I decided to install the game on an Android tablet so that I coud keep playing while making sure that the phone's battery would get topped off when I'd leave my desk, and the tablet (LG G Pad 8.3) has shown the very same behavior (i.e. the battery depleting while playing plugged to the USB charger), so I strongly suspect that it's a Lollipop issue more than a Yotaphone issue.
I've read somewhere that Lollipop, amongst other "features", exhibits a bug where the data connection will not time-out as it should, so the device actually remains with a more or less permanent live data connection, contributing greatly to reduce the battery life. Give that the aforementioned games are online games, I'm more than ready to believe in the existence of such a bug.
TLDR: if the battery dies completely, it can take quite some time for it to reharge enough to power-up the device properly. I'd leave your Yotaphone connected to a USB charger for a whole night, for instance, and see if that helps. Trying another charger (preferably 2 Amp, instead of the normal 0.5 Amp delivered by a USB cable), and/or another USB to micro-USB cable (preferably a short one, the longer it is the less efficient it is, generally), and see if that changes anything.
If that still fails to le the device restart, you're certainly out of luck and should contact Yota for a replacement (it is certainly covered by warranty, new as this phone is).
Hope this helps, let us know if you can bring it back from dead-phones-land!

or maybe some contacts at the usb port are brocken. did you try a qi wireless charger?

Dead YD206

So YD206 about a month old. Was connected to official yota charger (via a magnetic usb cable), noticed the plug at the phone end getting quite hot. Phone now essentially dead, wont boot, doesn't seem to charge. We also realised the charger had come out of the wall socket. But the yotaphone light was intermittently flashing on the charger.
Whilst I am inclined to blame the magnetic charging cable, is it possible for current to flow in reverse from phone to charger and essentially discharge the phone battery below acceptable levels?
Any advice on rebooting it (can't remove the battery like I would on a Samsung) so whats the procedure?

Just a follow up charger not the issue, it crashed in use and the power button became non-responsive, with the screen off, and the e-ink display on but also unresponsive. Did not turn on when connected to a charger. However when I connected it to my pc it did register in device manager as MTP device, so I knew it was still alive. Removed the sim and held the power button down for 10 seconds then it rebooted.
Hope this helps anyone else with a similar problem.
Failing that it would probably have to be left to discharge (might take a while if nothing is running) then powered back on with charger attached.

I have similar problem. My phone got hot while not charging (about 15% of battery) and crashed. Then forced reboot (hold power button for about 10 seconds) helped while phone was connected to Yota charger, battery was dead, but phone booted (EPD on, did not check rest) and got to about 81%. After removing it from charger, same thing happened again, no luck with forced reboot this time. Phone was blazing hot and did not respond, then crashed again. No response after connecting charger or forced reboot. Any experience with this issue appreciated.

SuperTukan said:
I have similar problem. My phone got hot while not charging (about 15% of battery) and crashed. Then forced reboot (hold power button for about 10 seconds) helped while phone was connected to Yota charger, battery was dead, but phone booted (EPD on, did not check rest) and got to about 81%. After removing it from charger, same thing happened again, no luck with forced reboot this time. Phone was blazing hot and did not respond, then crashed again. No response after connecting charger or forced reboot. Any experience with this issue appreciated.
Click to expand...
Click to collapse
It seems a battery issue. Have your Yotaphone a valid warranty?

casaprocida said:
It seems a battery issue. Have your Yotaphone a valid warranty?
Click to expand...
Click to collapse
I am not sure about my warranty, bought it off AliExpress, I guess I could try to send it to manufacurer (i heard Russia provides repair service).
EDIT ( t + 2 days): I managed to start my Yota again. I connected it to computer and after about 5 minutes, magic happened and phone started all by itself. I will try to find out more, will update this as soon as I find something

Man, you are more lucky than me, I have a dead yotaphone lying around here. It also died after connecting it to a bad power source.
In my case it was the usb-port of a monitor.
When I checked the usb-port with a cable with a volt/amp display I saw that it was going on and off very quickly.
But so I would say be careful where you connect your yotaphone to, it does not seem to handle weird power sources all too well.

tomgaga said:
Man, you are more lucky than me, I have a dead yotaphone lying around here. It also died after connecting it to a bad power source.
In my case it was the usb-port of a monitor.
When I checked the usb-port with a cable with a volt/amp display I saw that it was going on and off very quickly.
But so I would say be careful where you connect your yotaphone to, it does not seem to handle weird power sources all too well.
Click to expand...
Click to collapse
I actually thought about burning charging circuitry a lot. I wonder, if you would be able to test wireless charging. With some luck, it is independent enough to not be affected by burning micro usb charging route (depends where high voltage safety is implemented). If this make any sense to you, please give this a try (I think IKEA is place to go, they should have working wireless chargers in their model setups) and report back. If I am wrong in any aspect, I'd appreciate any correction with explanation.

SuperTukan said:
I actually thought about burning charging circuitry a lot. I wonder, if you would be able to test wireless charging. With some luck, it is independent enough to not be affected by burning micro usb charging route (depends where high voltage safety is implemented). If this make any sense to you, please give this a try (I think IKEA is place to go, they should have working wireless chargers in their model setups) and report back. If I am wrong in any aspect, I'd appreciate any correction with explanation.
Click to expand...
Click to collapse
Sorry for the late reply, did not see the quote, but it does not work with wireless charging either. I think the battery still has a lot of charge too. Thing is that the Motherboard also gets hot after a while when I try to charge it. I'm pretty sure my motherboard is dead. But I have another Yotaphone now, so maybe in the future I will test with every separable part replaced.

I use the charger from my iphone. It works great, although with the yotacharger also works well. Attention that I have a YotaPhone YD201 with Russian base and european compilation. Like I said the Iphone charger works great and doesn't warm my Yotaphone 2 . It might be a solution for your problems with charging.