[Q] Periodic battery usage fluctuations - Nexus 7 Q&A, Help & Troubleshooting

In the past few months, the battery on my (2012) Nexus 7 has been completely unreliable. It charges very slowly (roughly 2-5% per hour), and continues to discharge if used while plugged in. In general if left overnight it will charge to a full 100%, but last night it lost 3% from where it had been. Using Battery Monitor, I saw a recurring pattern in the current drawn by the device while plugged in. One or two times an hour, it would spike downward to between -700 and -1000 mA, before returning to a positive charging state. Looking at Battery monitor after a period of light use (chrome, pandora, facebook), the pattern remained consistent. Does anyone have any thoughts on what might cause such a periodic heavy power draw? Thanks very much!

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Charging with screen on - charges Evo better?

Yes, I know. We're all sick of these battery threads. But I just came across something I wanted to share with you all.
Before I continue: I don't use any task killers. And I've read every battery trick thread on here and on Android Forums, so I've done it all. The CDMA fix. Rooting and using OCWidget. Charging it to 100%, turning it off, and then cycling the charge with the phone in the off state. And of course, disabling every data hungry app plus setting screen brightness to 50%. This is my 3rd Android phone, so it's definitely not my first rodeo.
So last night I was using my Evo as it was on the charger. I was browsing the web, and checking out some new apps in the market, so the screen was on for quite a while. I took my Evo off the charger, did some heavy texting, some browsing, Facebook, Twitter, etc, etc, and about 5 hours later I was at 80%. I then put it on the charger, and went to bed.
Fast forward to this morning: Took it off the charger, sent a few texts, and I'm down to 95% within minutes. Of course this frustrated me, since last night I went an hour before it even dropped to 99%. It'll be getting some heavy use today, so the last thing I want to do is leave the house with my battery in the 80% range. I put it back on the charger, and resumed normal usage. Some texting, Facebook, Movies app, Netflix app. Eventually the charging light goes green again. Took it off the charger an hour ago, did some texting, stayed connected to WiFi,and I'm still at 100%. Whereas earlier this morning it dropped 5% in minutes under the same use.
Scratched my head for a second, and remembered that my phone was on and in use while charging last time, before I took it off and got great battery life.
So now, I've set it so my Evo's screen stays on while charging. I also use the Power Control widget to increase the screen brightness to 100% while charging. And then once it's off the charger, just drop it to 50%.
To keep the phone awake while charging:
Menu -> Settings -> Applications -> Development -> And then tap the check box next to 'Stay awake'.
Not saying this is guaranteed to work, and I have no rational explanation as to how this works, but it's definitely helping me. I'm going to do some testing and report back on a few things.
I think you might be on to something. I recently had an experience where my batter was around the 60% mark, I plugged it into my computer for about 30mins - 1hr and somehow it managed to charge to 100% battery in that short time span. Needless to say, the battery drained pretty quickly until it reached some stable point. I'll try the charge with screen on thing when I get a chance.
as odd as this sounds, i have notice the same thing when using my phone while on the charger then taking it off. I use screen cast when i'm at work, so my phone is always plugged into the computer. Once i leave work for the day my phone is usually fully charged or about 80% with moderate usage my phone is usually around 60-70% when i lay down to go to bed. Now on the weekened when i charge my phone overnight, the following day with moderate to heavy usage my battery drops to like 50% within a hour to a hour in a half. So i plug it in while texting or browsing, and when it get fully charged the battery seems to take 3-4 hours to get to 50% with moderate to light use. Weird
I've currently enabled every bell and whistle on my Evo so I can speed up the battery drain. I'm making note of the voltage reading at each percentage (via Battery Indicator), and then I'm going to charge it back up with the screen off to compare these numbers.
I think the issue isn't the charging with the screen on. I think there may be a "bug" that, when the phone hits full charge, it doesn't continue to charge but instead starts using the phone battery. Thus, when you charge at night, it's fully charged for a while, you start using it in the morning and it quickly drops to whatever has already been used (~94-95%). But, if you charge it and take it off soon after the light turns green, then it's fully charged and you're getting the full 100%.
I think there's a problem with the trickle charging.
gianmarco00 said:
I think the issue isn't the charging with the screen on. I think there may be a "bug" that, when the phone hits full charge, it doesn't continue to charge but instead starts using the phone battery. Thus, when you charge at night, it's fully charged for a while, you start using it in the morning and it quickly drops to whatever has already been used (~94-95%). But, if you charge it and take it off soon after the light turns green, then it's fully charged and you're getting the full 100%.
I think there's a problem with the trickle charging.
Click to expand...
Click to collapse
My testing confirms this theory. I put mine on the charger after work, and the light was green when I went to bed.. the next morning when I unplugged it, it dropped to 90% within a few minutes. Everytime I've unplugged it right after the green light comes on, it stays on 100% for at least 15-20 minutes of use.
gianmarco00 said:
I think the issue isn't the charging with the screen on. I think there may be a "bug" that, when the phone hits full charge, it doesn't continue to charge but instead starts using the phone battery. Thus, when you charge at night, it's fully charged for a while, you start using it in the morning and it quickly drops to whatever has already been used (~94-95%). But, if you charge it and take it off soon after the light turns green, then it's fully charged and you're getting the full 100%.
I think there's a problem with the trickle charging.
Click to expand...
Click to collapse
That explanation sounds accurate, so instead of doing all this it might b a simple tweak to not have this trinkle effect happen
Sent from my PC36100 using XDA App
It was mentioned in another thread that "trickle charge" gives the battery a better deeper charge. Perhaps a 500 or 700 mah charger will do the trick instead of risking a screen burn.

Evo Battery with 1.47 OTA Massive FAIL!

Since applying the 1.47... OTA, I can literally watch the battery drop minute by minute while the phoe is active.
Within the first 1 minute of removing the phone from the charger the Battery Status Pro reports the charge droping from 100% to 97%. That's a 3% drop in 60 seconds.
Within the first 3 minutes of active use BSP reports the battery drops to 93% charge. That's 7% loss in less than 200 seconds of use.
Now I'm not saying BSP is 100% accuerate but I expect it's not too far off.
Battery life with the Evo has never been phenominal but this seems rather extreem. The drop seems far faster now than when running the 1.32 release. And... while I am in a 4G enabled market, this is with 4G disabled and the phone running purely on 3G with no flickr, twiter, facebook or other feed widgets running and autosync disabled for all of them.
When I look at Battery Use under settings / About Phone / Battery the Android System is by far the largest user of battery, nearly twice the next closest user which is Cell standby.
Am I the only person experiencing this?
The phone was doing this before the 1.47 OTA, it's a problem with charging the battery in the phone. It does not charge properly for some reason and it will drop all the way down into the 80's within an hour of unplugging it. If you get an external battery charger and use it to charge the battery the phone will stay on 100% for an hour or more...
Have you removed the HTC people widget from home screen? The day I removed that was the beginning of decent battery life. Also try turning off the phone when charging - seems to work better that way.
I would try charging to 100%, unplug, wipe the battery, plug it back in again until the light turns green and try again and report back.
Sent from my PC36100 using XDA App
I wondered if it was the powered off portion of that battery trick that was doing it. Hmmm. I'll have to watch. Is there any link/source on the idea that the phone itself is not working so well at charging?
Out of that voodoo on the getting better battery life the only thing I could come up with was...-charges better when off, - you need to charge for a bit while on to reset the battery indicator, - and charge a bit while off to top it up.
So I was leaning toward it being a charging thing and not a battery thing...would like to see any technicals though and not just my guessing.
People widget has been long gone.
I gave the charge it with the phone powered off thing a try. The device was down around 80% charged when I powered it off and plugged it in. In about 5 minutes the charge indicator turned from amber to green as if it were fully charged.
I can't believe that the battery charged 20% in 5 minutes.
This leads me to believe that the first response is correct. The battery simply isn't charging fully in the phone. I believe I'll look for an external battery charger and give it a try. See if it makes a difference.
frankenstein\ said:
People widget has been long gone.
I gave the charge it with the phone powered off thing a try. The device was down around 80% charged when I powered it off and plugged it in. In about 5 minutes the charge indicator turned from amber to green as if it were fully charged.
I can't believe that the battery charged 20% in 5 minutes.
This leads me to believe that the first response is correct. The battery simply isn't charging fully in the phone. I believe I'll look for an external battery charger and give it a try. See if it makes a difference.
Click to expand...
Click to collapse
Seriously, try full-charge, wiping your battery data and then shutting it off and 'topping it off' and reevaluate the situation.
EDIT: The "topping it off" thing is all voo-doo as far as I'm concerned. I just do it to be safe, though I'm pretty sure it's ineffective.
I screw with my phone so much, so much flashing/restoring back and forth while on charge, between
charge, car charger, USB charge at work, wall charge, flashing again, kernel swap, restore back again...etc etc etc...that if I don't wipe my battery once I hit a full charge there is no way I can trust that meter to do anything more than change colors. I do it every few days when I notice the meter isn't being trustworthy.
If this doesn't work for you I'd say you probably have a bunk cell in your battery, and failing that your phone just might not be charging well.
Also, charge with the wall and not USB. USB takes forever. And 20% in 5 minutes isn't TOO far off if you are plugged into the wall and getting full-power charge. Maybe 10-12ish minutes, unless you were timing it very specifically....
I just got my bricked replacement. Here is the data from a 100% charged battery usage up time 18:13 .. Awake time 15:27 the battery is at 87%
funny im getting 20 + hours a charge after the OTA
with heavy usage

[Q] Battery overheating event - detailed case study

Historical phone performance:
Battery usage (slide 1) – phone uses up 21% in 9 hrs incl 1hr screen-on time and 23 minutes talk-time.
Charging (slide 2) - phone reaches peak battery temperature 105F as voltage increases past 70%, then battery temperature lowers. Max charging current 1500 – 2000 millamps, decreases back to zero causing the temperature to falls. Max voltage 3,450 millivolts.
Phone is rooted and generally operates great with very few problems.
The overheating event (slide 3)
9:50pm – placed phone on charger, using phone screen
10:30pm – stopped using phone, left phone on charger (normal routine)
11:20pm – batter reaches peak temperature of 110F as voltage increases past 70% and then battery temperature starts decreasing. Everythign seems normal at this point.
1:45am – battery temperature starts increasing again and increases to peak of 145F battery temp at 2AM. Bounces around in the 140-145F range.for the next three hours
NOTE – Even though at first glance it seems like a battery/charging problem, the current and voltage behave very similar to the previous normal charge. This seems to rule out battery/charging problem (?)
4:40AM – alarm goes off and I awake and find hot phone and unplug it from charger immediately. Took screenshot (slide 7) showing battery temp 135F and cpu temp 174F. (by the way in other screenshots, cpu temp is on the far right of my notification bar, battery level is on far left of notification bar, and battery temp is 2nd from left on notification bar... the battery temp showing on the notification bar in this particular screenshot is not updated yet because I just turned the phone screen on).
From this point on battery temperature drops significantly (in response to unplugging presumably). Note that GSAM battery monitor battery stats are wiped by unplugging charger, can’t retrieve what they were before.
04:52 – took GSAM battery stats approx. 12 minutes after unplugged. (slide 4) - Battery is down to 95% already and 56% used by apps (even though I have had screen on continuously). The two apps sucking up all the juice are Lookout and Mapquest. Lookout has been on for 13 minutes which is the entire time since the stats were reset when the phone was unplugged. Mapquest only shows as being on 10 minutes at this point. I checked GPS at this point and it was definitely enabled (I normally leave it enabled without any problem). I am not positive whether I disabled GPS at this point or not. I didn’t stop the apps… curious to see how they would behave. Turned off phone screen and left it alone approx. 05:05 until..
05:40 – took GSAM battery stats approx. 1 hour after unplugged. (slide 5) Battery is down to 79% (huge drain… I normally get 9hours plus before I get to 79%). Biggest users are again Lookout and Mapquest. Battery temp is 95F (in an ambient temperature around 70F) which is high considering the phone was not being used and not being charged.
05:45 - Uninstall lookout. I may have turned GPS off at this time (if I hadn't already done it at 04:52... not sure). Reboot. After reboot I did note GPS was disabled and Mapquest was not running. Phone has operated normally since (normal battery drain, normal temperatures).
Hypothesis – Rogue apps Lookout and Mapquest? But they didn't overheat much after battery was removed from charger (even though they continued to use abnormal battery). Maybe it only overheats with the combination of both the rogue apps plus the charging?
Also, would seem too coincidentl to have two different rogue apps show up at the exact same time. Maybe at least one of the rogue apps went rogue as a result of the high temperature.?
What do you think?
Update: charged overnight the following night and everything was normal, just like slide 2.

Sudden battery issues - stops charging anywhere between 77 and 91, sudden drops

I've owned my Note 4 since October 2014 and it's been working solidly since. Last Thursday, out of nowhere, I noticed that from a 14% charge, it suddenly dropped to 4%. I immediately scrambled for a charger and charged it back up to 100%. On Friday, I charged my battery normally again. Charging finished at 11 AM but the drain was abnormally high. My phone was warm to the touch and battery was dead in 4 hours. I was using the phone normally throughout that time, 4g on, location services/bt off, screen off for the most part. I ran OS monitor to see whether any app was locking up the CPU, but, as expected, the main CPU users were Android System and Android OS.
On Saturday, I charged the phone to full again, disconnected around 4 pm. Being that I was home, both wifi and 4g were off. Battery discharged normally, and was only down to 30% on Monday morning.
On Monday, I noticed that battery dropped from 21% straight to 11% straight to 4% in a few seconds. The drain from 4 to 3 to 2% was decent (few minutes of screen on time, on viber), then the phone shut off. I tried to charge the battery with the device powered off, but noticed that the phone simply stopped charging at 80%. I thought that was an abnormality. I tried wiping the system and app caches, but the problem persisted and drain still felt pretty fast. Tuesday night, the phone stopped charging at 91%, staying at the same level for 40 minutes before I gave up and unplugged.
My friend had purchased a fake OEM Note 4 battery and allowed me to try the drain/charge process using his battery to troubleshoot. When I first plugged his battery into my phone, the drain was high at about 1 percent per minute. When I tried to charge the battery, the charge level would not go beyond 90%. I switched on safe mode, but the battery did not charge any further either. I felt by then that something was definitely wrong with my phone. When I restarted the phone to get out of safe mode, though, it suddenly started charging again and hit 100%. With regular use, the fake battery gave me 16 hours of power, which I thought was relatively decent. Alas, when I started charging it again, it stopped charging at 77%. Battery Monitor Widget showed 0 mA flowing into the phone at the time, though the battery indicator in the status bar showed the lightning bolt.
I took out the fake battery and put in my original. It is now charging up normally, but I expect charging to stop before I hit 100%.
If anyone could provide possible explanations for what could be going on and/or other troubleshooting tips to try, I would really appreciate it. A factory reset would be my last recourse.
Thank you very much!
EDIT: My battery went all the way up to 100% this time. But it's the same one that got stuck (at 80% then at 91%) twice in the past.
I'm using two different Samsung chargers and different cords, by the way, and blew out the port with air prior to attempting to charge the fake battery that still stopped at 77%.
I had the same issue, took it to Samsung and they replaced the battery, it has been okay since that
tigsandmitch said:
I had the same issue, took it to Samsung and they replaced the battery, it has been okay since that
Click to expand...
Click to collapse
Really? I was ready to write off my battery and just buy a replacement, but what was weird was that even the newish fake battery wouldn't charge fully. That's what made me worried that it's my phone that's the problem.
It'd be great if this could be as simple as a battery problem.

Is it a battery problem or something else?

I used my s7 edge pretty much since the day its released. I noticed recently, my phone stopped charging, or at least charged very slowly. And the battery drains very fast as well, it lasted around 2-3 hours on a single charge.
But it still charged very slowly. I run Ampere and saw It only charges at 400mA and dropped to 40mA sometimes. I checked my charger and cable, they all worked fine on my other phone, quick charge worked as well. I had the samsung charger, some third party charger and an external battery from anker, none of them solved the issue. It takes up to a min to charge 1% with the screen on, it won't charge at all. I turned off a lot of background apps but that doesn't solve the problem.
battery usage : screen : 19% andriod system : 16% android OS 15% WLAN 15% facebook 8% youtube 6% media server 3% cell standby 3% google service 3% soundcloud 2% chrome 2% google 2%
The android system battery usage is pretty high IMO. Is it causing the problem?
Sanfasteryler said:
I used my s7 edge pretty much since the day its released. I noticed recently, my phone stopped charging, or at least charged very slowly. And the battery drains very fast as well, it lasted around 2-3 hours on a single charge.
But it still charged very slowly. I run Ampere and saw It only charges at 400mA and dropped to 40mA sometimes. I checked my charger and cable, they all worked fine on my other phone, quick charge worked as well. I had the samsung charger, some third party charger and an external battery from anker, none of them solved the issue. It takes up to a min to charge 1% with the screen on, it won't charge at all. I turned off a lot of background apps but that doesn't solve the problem.
battery usage : screen : 19% andriod system : 16% android OS 15% WLAN 15% facebook 8% youtube 6% media server 3% cell standby 3% google service 3% soundcloud 2% chrome 2% google 2%
The android system battery usage is pretty high IMO. Is it causing the problem?
Click to expand...
Click to collapse
I'd try rebooting the phone, make sure all apps are 'off', along with Wifi and data, location, etc.
Turn the screen/phone off, not shut down. See what happens to battery drain then, with nothing functioning, effectively. Poor battery life, I'd probably be replacing the battery, given the other info you have provided.
Latest fw is absolutely no state to be publicly released killed my phone in addition to similar problems as above.

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