[Q] Defy Battery Drain - Defy Q&A, Help & Troubleshooting

My Motorola Defy MB525 is experiencing strange battery drains. It usually drains itself regardless of usage or power state. Even in a shut down state, the battery still continues to discharge. The strangest of all is that after each charge I'm able to use the device for about 36 - 40 hours, regardless of none, low, mild or heavy usage. For about 2 years, the battery lasted around 3 - 7 days.
At first I though, it was the battery. However, after I've purchased a new original Motorola battery, the issue still persists.
In addition, the first signs of this issue arose right after a CM11 change from the stock Android 2.2.2 and continued even after I've reinstalled the Android available .SRT file over RDS Lite for the 2.2.2 version.
I've tried different suggestions and tutorials (for example - CPU Deep Sleep, WiFi power management, Baseband Change, etc.) available on the forum, but without any use.
Thus, my only question :
Even tough the device works without any major glitches, as expected from such a device. Does the above mentioned issue relate to a Motherboard or Power Management/State Chip failure?
Btw...I've took the device apart to check if there are any signs of shorted elements or short-outs. Sadly, nothing of sort.
Any help and/or suggestion would be appreciated.

Hi, maybe try another CM11 nightly or another custom ROM to see if the same problem persists?

this [http://forum.xda-developers.com/showthread.php?t=1778492 thread] goes in-deep on battery problems, but, knowing a lot about electronics, I think in your case is just that inside the phone, there is a small switching-mode power supply, and it have a (fairly) large capacitor that can leak some current. When capacitors age they became more of a resistor... and that's why most of modern electronics break up. I would blame hardware in this case.

Related

Always power off without low power alert

If my HD has 20% power left and is running program, it will always power off without low power alert after a few minutes. Then, you must recharge it for power on.
In addition, I found that the refresh interval of power indicator looks slow, in other words, after it has been charged and run for a while, the power indictator is still 100%.
Can anybody tell me the reason and how to resolve it? Thanks!
Are you using the original battery?
Battery level is rather inaccurate, especially with 3rd party batteries, so don't take it for granted.
The battery is certainly an original battery.
Is there a possibility that the issue is relative to ROM version?
I have a experience that I flashed a rom of version 21109 into my HD, the issue occured every time. Afterward, I reflashed a stable rom of version 20769 back to it, the issue has never occured. But, several days ago, I flashed the newest radio into my HD, after that, the same issue occured anew.
I'd blame the battery, if it dies when your unit reports 20% charge, it must be in a pretty bad shape. If you can find a spare battery, give it a try...
was anything more found out about this? I also find my battery indicator very slow to update....soft reset my device and lost 5% power according to the battery...I have even had the reverse effect after a charge,....soft reset after a charge and seen MORE power than indicated.
This is making me paranoid and search for every last tweak to save power but it might be that the indicator is wrong in the first place - ideas?
Charge the battery full and let it drain to zero,and one time again.this should recalibrate the powermeter.
or your battery is old and broken...if you often charge your device when its not even required the battery will loose power and be dead in a very short time.
i know my english is not the best,hope you understand what i mean

[Q] Battery Drain

I´ve just come back from a two month expedition on Borneo. But when i got back to civilization and turned on my trusty N1 I quickly realized that my battery performance has dropped significantly. Before I usually had one day of heavy use (including Wifi, 3G, tethering and GPS usage), but now I only have about 7 hours standby with everything except GSM turned off. Which renders the phone useless for my (normal) use. The phone actually consumes so much power that the battery level drops while charging. The only way to charge it up is to turn the phone completely off.
I flashed the RoDrIgUeZsTyLe™ MIUIMOD -ROM before I left for my trip, so I thought maybe that was the problem (some bug i the kernel or something), so i flashed back to CM6 with no success. I have also tried a new battery.
Anyone knows what can be the cause?
All help is deeply appreciated --- I miss my good old N1!
I accidentally placed this in the wrong section - can anybody move it to Q&A?
Try the battery app in my sig to pull your battery values, then post in that thread and one of us can help you see what's happening with your battery.
maybe the charger is the problem?
Just throwing it out there... I've seen it happen for Laptop users...
Try the battery app in my sig to pull your battery values, then post in that thread and one of us can help you see what's happening with your battery.
Click to expand...
Click to collapse
Voltage (mV): 4035.84
Current (mA): -464.98
Temp (C): 30.2
Percent: 90
Batt age: 94
Full40(mAh): 1452
Min Chg Curr(mA):80
Min Chg Volt(mV): 4099
Empty Curr (mA):200.0
Empty Volt (mV): 3.426
Capacity(mAh):1273
Aged Capa(mAh): 1393
BTW...I have also tried several different chargers without any success.
Hi,
I had similar problems with my rooted N1 with stock Froyo.
The problem for me was a radio image older than regular. Baseband version should be something _4.06 or higher.
You can check this information in Settings ->About Phone
Sent from my Nexus One
Fulvio Minichini said:
Hi,
I had similar problems with my rooted N1 with stock Froyo.
The problem for me was a radio image older than regular. Baseband version should be something _4.06 or higher.
You can check this information in Settings ->About Phone
Click to expand...
Click to collapse
I got 32.41.00.32U_5.08.00.04 so it doesn't seem to be old, but I'll try to update the radio anyway with a custom stock rom from modaco. Will let you guys know if it helps
Update: I'm now back at *****_4.06****. No change
My first thought is: what level of power did you leave your battery with before you went away?
Lithium batteries are permanently damaged if the voltage drops below a certain level. Leakage will mean that any battery left for a while will lose charge.
Therefore, if you leave a battery with close to zero power left for a long time, leakage can mean the charge level drops below the critical minimum level and the cells become damaged.
As such, it is recommended to never store lithium batteries with below 40% charge, and to store them in a cool environment, since leakage is faster at higher temperatures.
Yeah, that was my first thought too, since I forgot to turn it off before I left (the phone was stored in a room with AC at least). However, I have now gotten a new battery and it doesn't help...
I have tried to check if there are any programs that are running in the background that draw unnecessary power, but i cant find any ---at least not with system panel. The cpu-load also seem to be normal.
Anyone got some ideas?
Thats really wierd... The only thing you can do is reflash the radio and flash it to stock. Then use the new battery and charge it overnight - so it overcharges slightly. Let it totally drain till the phone turns off, and repeat a coupla of times. Ignore the levels reported by the phone.
See if it starts to behave normally after that. If not you either have another dud battery or there's something wrong with the charging circuit in your phone.
If you have a friend with an N1, you could try charging your respective batteries in your phones, then swap batteries. See how much time each phone lasts
Thanks for the tip.
I'll try that before I buy a new cellphone.

Swapping batteries and batterystats.bin

I did some searching and reading and only found speculation on this subject, and during the holidays I have been mostly desk-bound at my home office with very little phone traffic, so I thought I'd post my results after doing some testing.
For those who don't want to read, the bottom line is, if you swap batteries, (especially using batteries of different capacities) I believe you definitely should wipe your batterystats.bin file each time you swap them if maximum runtime is your goal.
Why did I question this in the first place? I saw a dev post a comment that the battery drivers do not reference this file at all. I wasn't able to find any clear explanation of what is actually in this file. I'm running Nero v3 with Voodoo, and after I flashed it, my fully-charged stock battery only lasted about 45 minutes. All these things made me wonder whether it made a difference, and since my previously-fine stock battery suddenly wouldn't last an hour, I had to do something anyway.
For test purposes I attempted to eliminate as much random activity as possible. I shut down my e-mail client and data sync and forwarded my cell calls to my home office land-line. I'm in the camp that believes (from experience) that a good strong WiFi signal to the closet ten feet away uses far less juice than trying to maintain radio contact with a cell tower 2 or 3 miles away, so in this case I switched off WiFi to ensure *faster* power usage. I didn't want to do a crazy-fast maximum-extreme battery drain, though, so I found that streaming radio at full volume using TuneIn resulted in noticeable drain, but also surprisingly extended runtime. I made sure the phone was in the same physical location for the duration. (I know there are still a million-and-one variables at play, but I believe the "big picture" conclusion is valid.)
The battery I'm referring to as G9 is the original "good" battery that shipped with the phone. The G7 batteries are those cheap Chinese knock-offs, the ones with the duplicated serial numbers. These have very different capacities. I believe the G9 is 1500mAh and the G7 has been estimated at 700 to 900 (it is marked as 1200 but this is clearly false). I have two G7s. All batteries were fully charged on an external stand-alone charger. The batterystats.bin file was wiped using Clockwork Recovery. I ran the application with the display off, only turning it on about once an hour to check the battery level. I let it run until the phone shut itself down.
First test:
Install G9, wipe stats: 7 hours 14 min to shutdown
Install G7 #1, no wipe: 4 hours 2 min to shutdown
Install G7 #2, no wipe: 4 hours 4 min to shutdown
Install G9, no wipe: 6 hours 59 min to shutdown
Second test:
(I already saw [above] what the G9 does with a clean wipe)
Install G7 #1, wipe stats: 5 hours 31 min to shutdown
Install G7 #2, wipe stats: 5 hours 27 min to shutdown
As an aside, I'm pretty surprised that playback of streaming-data radio at full volume will last more than 7 hours. I figured I might get 3 hours or so. This suggests to me that both the phone hardware and Android itself is actually very power efficient -- streaming radio is not exactly optimized for power saving, and the stock speaker is quite loud.
Since the phone actually shuts itself down -- it doesn't simply bleed the battery dry until it just dies from power-loss -- I suspect it uses this data to profile how the battery drains to predict when it will become nearly depleted so that it can perform a clean shutdown. And swapping batteries with very different "behaviors" simply throws that off completely. You can see I got a full hour and a half more out of my G7 batteries just by wiping, and my G9 lost about 15 minutes of uptime after the stats were "contaminated" by a pair of G7 runs. I also thought the consistency of my back-to-back G7 runs was interesting.
The probable (and unavoidable) downside to frequently wiping your battery stats is that it also probably defeats any long-term battery management strategies designed to extend the life of your battery. You see this kind of thing most obviously on laptops where the battery management software intentionally runs on battery power even when you're plugged in, letting the battery drain to some point based on the software's evaluation of your battery's health before allowing it to charge again. I'm not sure if Android or the Vibrant does this, but it seems likely it does based on people's complaints about things like the "15% charge drop" issue when they unplug from the charger or USB.
It doesn't appear that our batteries have electronically-readable serial numbers, and I have to assume knockoffs like my G7s wouldn't bother to implement those correctly anyway. But optimally we'd have different profiles for different batteries. Maybe in Galaxy's successor...
Why doesn't the driver reference batterystats.bin? I don't know, but what would be interesting is to scan the released source to see what DOES access it. I suspect it also tracks all that other power-related data (like the detailed battery history information in the *#*#4636#*#* menu), and so I further speculate the file is managed by some centralized logging-style interface, and the battery driver is just one piece among many which communicates with that interface. But I've never bothered to actually grab the code from Google and that's nothing but pure speculation.
Anyway -- wipe it when you swap it.

Still having charging issues with 4.2.2

I'm really frustrated because i really used to love the n7 so much I was an early adopter and bought another one after I dropped my first and then went on to buy my girlfriend one. But after being plagued with this issue and stuck on 4.1 its just not the same anymore since I cant flash custom roms all day :/
I've been having a charging issue with android 4.2.1 since it came out (both stock and all the roms I tried) but I noticed that whenever I reverted to 4.1.2 the issue went away completely. So I've been waiting for 4.2.2 to come out for a while now to see if it fixed the issue and after flashing the update tonight it seems to have the same problem.
I've tried searching for months now and haven't found any answers.
So this is the issue with both 4.2.1 and 4.2.2:
The battery charges at an insanely slow pace to the point that it ruins the tablet completely. I'll plug it in over night for 8+ hours and it will not gain more then 40% battery life in that time.
Its to the point that when I was just using it right now on the charger with brightness turned all the way down and nothing on other then sync and WiFi that light web browsing for 10 mins caused it to discharge a percent after being plugged in for 19 minutes.
Notes:
Its a c70 16gb
I tried 3 different stock N7 chargers with stock cables as well as trying them with other cables.
I'm not plugged into any kind of extension cords and I've tried multiple wall sockets at different locations.
My girlfriends nexus 7 32g charges fine on 4.2.1 and I have not updated her to 4.2.2 to test yet.
I haven't checked the battery connection because like I said whenever I revert to stock 4.1.2 or any 4.1.2 rom it charges in 4 hours flat or 6 hours with heavy usage while charging.
So anyone have any ideas? If not I guess I have to rma.
Do both, yours and your girlfriend's devices take that long to charge?
sl4y3r88 said:
Do both, yours and your girlfriend's devices take that long to charge?
Click to expand...
Click to collapse
Nope her nexus 7 charges fine. ( a little slower on 4.2 then 4.1 but nothing like mine)
Her nexus does have issues with turning on sometimes on 4.2.1 like a lot of other users but its nothing holding the power button for 10 seconds doesn't fix.
It also just noticed it seems to discharge at an extremely fast pace. (still on 4.2.2)
It just dropped from 55% to 51% in the time I've typed these responses with brightness all the way down.
So anyone want to try and help me figure this out before I send it in friday? I called it in to Google play device support to try and report the software bug and they said its the first they heard of it and they would pass it on but I felt like the rep didnt want to help as I bought it from a third party. I'm willing to do any tests suggested and hop between software versions to try and figure out this bug.
Why do you think it is a "software bug" when millions of people running the "same software" don't experience the same behavior?
I realize that software can exhibit data-dependent behaviors, and thus exhibit low occurrence rates... but there is no "software" involved in charging the battery.
Do you think a booted Linux kernel is needed to charge a battery? How would the battery get charged when the device is turned off in that case? C'mon!
Send it back and tell them the battery (or charge contoller CIRCUIT) is defective.
If it's out of warranty, PAY them to replace it.
bftb0 said:
Why do you think it is a "software bug" when millions of people running the "same software" don't experience the same behavior?
I realize that software can exhibit data-dependent behaviors, and thus exhibit low occurrence rates... but there is no "software" involved in charging the battery.
Do you think a booted Linux kernel is needed to charge a battery? How would the battery get charged when the device is turned off in that case? C'mon!
Send it back and tell them the battery (or charge contoller CIRCUIT) is defective.
If it's out of warranty, PAY them to replace it.
Click to expand...
Click to collapse
Then how do you explain that if right now I flash back to 4.1.2 it will work fine? If you want I'll provide screenshots.
I just flashed back to 4.1.2 this morning and it worked perfectly. Just now I flashed codefires 4.2.2 build and the problems back.
Please explain how that is hardware related.
I may of jumped the gun assuming it was a charging issue. It seems like it might be a battery drain issue. Here's a couple screenshots from a fresh install of codefirex 4.2.2 build.
Sent from my Nexus 7 using XDA Premium HD app
All I was trying to say is that when the OS is booted, at most all it does is monitor battery voltage and current - it doesn't get actively involved in control of charging circuitry.
At most this historical data can be used to *predict* when the battery will run out of juice, and this number is what is shown to the user as a % charge number. Hopefully that allows the prediction to be sort of correct as the battery ages and it's characteristics change.
This "calibration data" is only used for prediction - it does absolutely nothing to alter the rate at which current is drawn from the battery by the motherboard, nor for attempting to alter the behavior of a battery charge controller.
Li-Ion and Li-Polymer batteries are indeed complicated enough that they should not be charged by extremely simple circuits if a long operating lifetime is desired. For this purpose though, monolithic battery charge controllers chips are used - they do not need any assistance of a micro-controller or advanced CPU running a modern OS. That's why they are able to charge batteries rapidly and appropriately when the motherboard is in a "powered down" state.
Relative to a big multi-core CPU chip, which might have hundreds of millions of transistors, battery charge controllers are extremely small circuits - they are sold by the billions and cost in the ballpark of one to several pennies. They don't need the support of a CPU or even a microcontroller to operate correctly.
Good luck with your tab; I hope you enjoy it.
bftb0 said:
All I was trying to say is that when the OS is booted, at most all it does is monitor battery voltage and current - it doesn't get actively involved in control of charging circuitry.
At most this historical data can be used to *predict* when the battery will run out of juice, and this number is what is shown to the user as a % charge number. Hopefully that allows the prediction to be sort of correct as the battery ages and it's characteristics change.
This "calibration data" is only used for prediction - it does absolutely nothing to alter the rate at which current is drawn from the battery by the motherboard, nor for attempting to alter the behavior of a battery charge controller.
Li-Ion and Li-Polymer batteries are indeed complicated enough that they should not be charged by extremely simple circuits if a long operating lifetime is desired. For this purpose though, monolithic battery charge controllers chips are used - they do not need any assistance of a micro-controller or advanced CPU running a modern OS. That's why they are able to charge batteries rapidly and appropriately when the motherboard is in a "powered down" state.
Relative to a big multi-core CPU chip, which might have hundreds of millions of transistors, battery charge controllers are extremely small circuits - they are sold by the billions and cost in the ballpark of one to several pennies. They don't need the support of a CPU or even a microcontroller to operate correctly.
Good luck with your tab; I hope you enjoy it.
Click to expand...
Click to collapse
Thank you for taking the time to write out this detailed explanation. I read it over a couple times and that all makes a lot of sense and now I have a little better understanding of how things work charging wise.
But I still can't wrap my head around how the problem DISAPPEARS COMPLETELY on any 4.1 based build...
I'm not trying to contradict you in anyway it seems like you are way more knowledgeable then me on the subject.
It just doesn't make any sense and I was hoping you could make more of it for me.
Maybe it isn't the charging but a battery drain issue something on 4.2 based builds is draining more current then the charger can dish out.
But while i was doing research I read that chargers up the current they dish out if the device is in use. Is that correct?
I've looked into the media server bug but as I just did a fresh install of stock 4.2.1 and haven't changed or added anything to the file structure that wasn't included in the factory image, I also went through and turned off the keyboard press sound and all other sounds like explained in some of the threads I have read. I also read that the problem is supposed to be fixed in 4.2.2. I also haven't installed any apps from the market.
I guess all I'm looking for is the answer to this question:
Could there really be a hardware related problem of any sort (not just charging and battery problems but anything) that causes problems with 4.2 based builds specifically but doesn't cause problems with 4.1?
If the answer is yes then I don't have to feel bad about sending it in but if its software based issues I'll be upset that I wasn't able to fix it and gave up.
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
projectzro said:
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
Click to expand...
Click to collapse
I'll give this a try right now then post results, the battery is already pretty low so It shouldn't take very long. Thanks for the response.
projectzro said:
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
Click to expand...
Click to collapse
So I let it run dry and am getting some weird behavior...
The dead battery symbol did not pop at all. It actually booted played the low battery sound half way through the nexus logo loaded into the OS and immediately was greeted by the battery to low logo powering down message and then it returned off. It did this cycle all the way through three times in a row before holding the power button did nothing. I let it sit for a minute before trying again and I got another boot out of it all the way to the OS again. But I've yet to be greeted by the battery with the cross symbol. Holding the power button will do the cycle described above or do nothing at all.
krisserapin said:
But while i was doing research I read that chargers up the current they dish out if the device is in use. Is that correct?
Click to expand...
Click to collapse
Well, the 120v->5v converter certainly can be providing more current @5v because the device is active, but that's only because the motherboard is drawing current in parallel with the battery charging circuit. It doesn't mean the battery charge rate is higher.
krisserapin said:
Could there really be a hardware related problem of any sort (not just charging and battery problems but anything) that causes problems with 4.2 based builds specifically but doesn't cause problems with 4.1?
Click to expand...
Click to collapse
I suppose so.
I would do a few things to determine whether that is a reasonable hypotheses, though.
1) See how fast the battery charges with the tablet turned off. Should be close to 40%/hour for a new battery. You know there is no "software" running with the tablet turned off, so if you don't see some reasonable number here (say > 20%/hr) then a bad battery or charge controller circuit in the tab are the most likely culprits. Also, if the temperature rise of the tablet while doing this seems higher than the gf's unit, that would implicate the battery, not the charging circuit.
2) There's software, and then there's software. (Preinstalled vs. User installed) Run the battery down a ways, and then observe the battery charging rate with the device on but screen off (sleeping), but on a stock 4.2 install with ZERO user apps installed. Then, install/restore all your favorite apps, reboot, maybe use a couple of your fave apps, and repeat the same charge rate trial (screen off/sleeping). Are there large differences between the two cases? If so, that would implicate one of your apps in causing either lots of additional compute operations or preventing entry into the LP0 state (perhaps because of wakelocks?)
The thing is, the N7 battery is rated at 4325 mAh; that is sort of the same thing as 4.325 amps of current for 1 hour. (Voltage range of roughly 4v to 3.5v).
So, if a "good battery" can be charged in 2.5hrs, that is sort of like stuffing 1.73 amps into the battery for that time (1.73 x 2.5 = 4.325 A-h or 4325 mA-h). That's pretty near to the max capacity of the AC charger (2A)
Now, some users have reported discharging their tabs in 4 hours under heavy continuous use; that would be about 1.08 amps for 4 hours.
Since the wall charger is rated to produce 2A, this suggests that very heavy usage simultaneous with charging would indeed cause battery charging to slow down significantly - let's suppose it drops from 1.73a to 0.65a. Now it takes the battery 6.6hrs to charge ... but that is still just over 15%/hr ... with the tab in active use.
But that's not what you were noticing - you were seeing much worse charge rates than this when the tablet was supposed to be more or less idle!
Finally I should point out that I previously mentioned that the % charge number is a prediction, not a measurement! If for some reason this number were screwed up, then the "charge rate" observations could be completely screwed up. (Think of this as being analogous to trying to partially fill a gas tank in a car or estimate fuel mileage with a broken gas gauge) The only way to be sure that you are not falling victim to something like this is to record battery voltages - the 100% level should be up around 4v, and the 10% values down around 3.5v.
You can observe this value at /sys/devices/platform/tegra-i2c.4/i2c-4/4-0055/power_supply/battery/voltage_now
(note value is reported in uV)
Whew - long post. It doesn't directly answer your question about "why was 4.1 so different?" - but gives you an idea about why I was skeptical when you saw charging rates as low as you did.
I dunno, maybe the % charge prediction value numbers are screwy on your tab for some strange reason in 4.2, perhaps because of a minor hardware difference. I can't rule it out - I once saw a bug expression in a hardware/software combination that required three independent conditions (from three separate vendors!) to have precise configurations before the bug would show itself.
I hope this post gives you some ideas to try; it certainly doesn't give a solution.
Good luck - if you feel like spending more time investigating, go for it; just don't let the clock run out on the warranty period if you have one left.
bftb0 said:
Well, the 120v->5v converter certainly can be providing more current @5v because the device is active, but that's only because the motherboard is drawing current in parallel with the battery charging circuit. It doesn't mean the battery charge rate is higher.
I suppose so.
I would do a few things to determine whether that is a reasonable hypotheses, though.
1) See how fast the battery charges with the tablet turned off. Should be close to 40%/hour for a new battery. You know there is no "software" running with the tablet turned off, so if you don't see some reasonable number here (say > 20%/hr) then a bad battery or charge controller circuit in the tab are the most likely culprits. Also, if the temperature rise of the tablet while doing this seems higher than the gf's unit, that would implicate the battery, not the charging circuit.
2) There's software, and then there's software. (Preinstalled vs. User installed) Run the battery down a ways, and then observe the battery charging rate with the device on but screen off (sleeping), but on a stock 4.2 install with ZERO user apps installed. Then, install/restore all your favorite apps, reboot, maybe use a couple of your fave apps, and repeat the same charge rate trial (screen off/sleeping). Are there large differences between the two cases? If so, that would implicate one of your apps in causing either lots of additional compute operations or preventing entry into the LP0 state (perhaps because of wakelocks?)
The thing is, the N7 battery is rated at 4325 mAh; that is sort of the same thing as 4.325 amps of current for 1 hour. (Voltage range of roughly 4v to 3.5v).
So, if a "good battery" can be charged in 2.5hrs, that is sort of like stuffing 1.73 amps into the battery for that time (1.73 x 2.5 = 4.325 A-h or 4325 mA-h). That's pretty near to the max capacity of the AC charger (2A)
Now, some users have reported discharging their tabs in 4 hours under heavy continuous use; that would be about 1.08 amps for 4 hours.
Since the wall charger is rated to produce 2A, this suggests that very heavy usage simultaneous with charging would indeed cause battery charging to slow down significantly - let's suppose it drops from 1.73a to 0.65a. Now it takes the battery 6.6hrs to charge ... but that is still just over 15%/hr ... with the tab in active use.
But that's not what you were noticing - you were seeing much worse charge rates than this when the tablet was supposed to be more or less idle!
Finally I should point out that I previously mentioned that the % charge number is a prediction, not a measurement! If for some reason this number were screwed up, then the "charge rate" observations could be completely screwed up. (Think of this as being analogous to trying to partially fill a gas tank in a car or estimate fuel mileage with a broken gas gauge) The only way to be sure that you are not falling victim to something like this is to record battery voltages - the 100% level should be up around 4v, and the 10% values down around 3.5v.
You can observe this value at /sys/devices/platform/tegra-i2c.4/i2c-4/4-0055/power_supply/battery/voltage_now
(note value is reported in uV)
Whew - long post. It doesn't directly answer your question about "why was 4.1 so different?" - but gives you an idea about why I was skeptical when you saw charging rates as low as you did.
I dunno, maybe the % charge prediction value numbers are screwy on your tab for some strange reason in 4.2, perhaps because of a minor hardware difference. I can't rule it out - I once saw a bug expression in a hardware/software combination that required three independent conditions (from three separate vendors!) to have precise configurations before the bug would show itself.
I hope this post gives you some ideas to try; it certainly doesn't give a solution.
Good luck - if you feel like spending more time investigating, go for it; just don't let the clock run out on the warranty period if you have one left.
Click to expand...
Click to collapse
Wow thank you so much for the help. I'll play around with this tonight and see what happens. If I can't figure it out by the morning I think I'll be able to RMA it without feeling like I just rolled over and let my n7 get the best of me.
So after charging it on stock 4.2.1 with the power completely off it only charged 3% in a little over a hour and voltages read 3.6. I'm gonna leave it on the charger over night turned on starting from 3% with only two extra battery monitoring apps installed and report back in the morning with screenshots of the results. After that ill probably revert to 4.1.2 drain the battery fully, charge it off for an hour report the values then let it charge fully with the battery apps on for reference take a few more screenshots then lock the bootloader install the ota and ship it off to good old ASUS since it sounds like its hardware from whats been explained.
FWIW, I drained my N7 last night (LOL, typing novels into XDA threads) - when I finished I was at 6% charge - that was 3.66v. In the morning @ 100%, the battery voltage was 4.1-something.
Sounds to me like you've definitely got a hardware problem.
Good luck with the RMA.
Canyou help me?
Since I flashed 4.2.2 my 240V-USB charger only cahrges thes battery about 5% in one hour.
Before (with 4.2.1) It was definitely faster. It charged more tha 5% per hour (maybe 20-25%).
I double checked the plug in the socket. checked the correct fit of the USB cable on the docking station.
Everything fits tight. No wiggle.
It must be software related, since it started after flashing the OTA zip from 4.2.1 to 4.2.2
Polarfuchs said:
Canyou help me?
Since I flashed 4.2.2 my 240V-USB charger only cahrges thes battery about 5% in one hour.
Before (with 4.2.1) It was definitely faster. It charged more tha 5% per hour (maybe 20-25%).
I double checked the plug in the socket. checked the correct fit of the USB cable on the docking station.
Everything fits tight. No wiggle.
It must be software related, since it started after flashing the OTA zip from 4.2.1 to 4.2.2
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Click to collapse
From a partially charged state, say below 50%, turn the device off, (NOT sleeping, but powered OFF) and put it on the charger for one hour.
It should charge at around 30-40%/hr.
As I pointed out above, how is it possible that software would be affecting the charging with the device turned OFF?
I believe you are seeing exactly what you report; my best guess is that a hardware problem occurred just about coincidentally with your upgrade. Just coincidence - not causation.
You also should inspect the battery voltage (see above for path in /sys) in case something crazy is happening with the %charge *prediction* (it is not a measurement) - because the total charging range is from about 3.65v-4.15v, a normal charge rate should be roughly 150 to 200 mV/hr
good luck

[Q] Battery problem - suddenly turn off

It’s been a while that I have a strange problem with my batteries. I used two different batteries, both original, charged with the original charger support for the second battery (sell in bundle with it).
It’s almost two months that my phone started to turn off suddenly when the battery level is around the 30%, with both of them. I thought it was a problem related to the batteries age, since I’m using them in the last 2 years.
I tried anyway to contain the problem. As first option, I did a battery calibration. To do this I needed to discharge all the juice from batteries. I noticed that the residual 30% that I saw before the phone turn off wasn’t a fake value: it was real.
When I turn on the phone in recovery, the battery level is exactly the same that I have when phone turn off itself. Moreover, to reach 0% of battery level I have to wait a while and I can keep the screen on (always in recovery) for about an hour. On the other hand, if I try to restart the system, the phone turns off just after the Samsung logo of starts a non-sense bootloop.
Considering what I ‘ve written above, I think that my problem it’s not an hardware problem.
Does anyone have similar problems? Do you have any suggestion to avoid it?
As supplementary information, I’m running the last Italian official firmware with TWRP and root.
same problem
I am note 4 owner for 1 week now
it is an used phone (rebuy)
original rom 6.0.1 newest updates
on delivery the batterie was on 0%
first time use it shutdown at 35%
without warning
now after multiple charging and calibration
it shutdown at 20%
in 2 days I will get new Batterie and I will check again.
maybe batterie is old
Similar issue in the last week or so with my N4. Original replacement battery, 10 month old, turning off with no warning on reaching between 20-15 % charge mostly if i try to use the camera. I've put back the original battery and seems fine for now. Ordered another battery, Anker this time, just in case
Yeah Samsung carefully crafted these batteries so that they won't work any more after six months of usage of something. Mine is nine months old, the phone itself, brand new, and mine turns off at various battery percentages, sometimes its 5, sometimes its 12, I have stopped caring and I charge whenever I get a chance.
Conclusion Faulty Battery Only
Any battery poerventage is mainly determined with help of its volatage. As battery discharges this voltage also reduces. As battery grow older, we is gradually unable to handle the load as it used to when new one. Also battery life is determined by its charging and discharging cycles. It was all about basic. Now talking about note 4, being andriod fone and requres lot of battery so we usually charge it for 2 times depending on use.
The same problem was faced by me as well for note 4 at 30% it used to reboot all of sudden and thereafter bool loop (in actuality it is not as battery deoesnt handle load and it again starts to boot so no home screen). Replaced the battery with original one a month ago and now issue till date and fone lasts below 5 to 10% with 4G on and doing browsing.
So it is concluded for sure that battery problem.
Weird thing last night i experienced the same issue! And my phone is only 8 month old, i think this issue it's related to Samsung updates.. my phone did shut down in exactly 30% and started to go in bootloop i removed the battery and put it back and still the same i was about to factory reset my device for god sake ? luckily i did connect my charger before i factory reset my phone i gave it one last try and it did boot normally.
So i am not really sure what is going on.. no more updates for me unless it's a major changes
Sent from my SM-N910G using Tapatalk
Happened to me too. I think it's the battery, I tried several batteries, some cause sudden power off some doesn't.
I'm upping my thread after two months to say that I solved my battery problem changing them. I bought a new one from Samsung official store and now I'm able to do more than 4 hours of SOT and charge phone once in two days (Red Dragon Note 7 porting). Before to change, I was not able to use any Sammy ROMs, due to several reboots and disgraceful battery life.
I don't know if the battery is the guilty for everyone's problems, but I really suggest to try to change it. Just, be sure to buy an original one, because there are a lot of genuine clones, especially on e-commerce sites.
For what regards the problem itself, I think that the cause could be the use of a different charger (Samsung, but for an earphone), coupled with the extra battery kit. Unfortunately the original adaptive fast charger stopped to work a month after the phone arrived and I didn't bother about it.
So, I also suggest to use only the original cables to charge the device.
I hope that this testimony will help someone with the same problem and, at same time, I also hope that Samsung will consider to use again removable batteries to give people the opportunity to do what I did.

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