Develop Bugs

New Battery Theory - Bad Percentage Reading

Hey all, so I have a different theory on the GNex battery issue but I'm not sure how to test it. It also might explain why there has been such a discrepancy in people's battery stats.
My theory is that there is something wrong with the way ICS/GNex is charging/reading/identifying battery information. Here are a few of the reasons why I think this is the case.
1 - My phone will occasionally charge absurdly fast, like 20 percent in 10 minutes... but then it will die equally as quick. My first thought was that the phone just charges and discharges quickly... BUT
2 - After charging for, say an hour, when I do a battery pull and let it sit for a minute or two before putting it back all of a sudden my super quick battery charge to 62% is now only at 37% (actual numbers that happened to me tonight). So why did I do a battery pull...?
3 - Because I noticed that after 10 minutes my phone had gone from 62% to 56% and I thought that was absurd. Once I did the pull and was back to my (as I like to call it) normalized battery percentage I have only dropped 15% in 2 hours and that includes heavy data usage on maps, navigation and texting. And another strange thing
4 - I have actually seen it go the other way! I once was around 30%, rebooted the phone and it jumped to 50%. Now that I'm thinking about it I often see weird fluctuations in my battery reading. One minute it will be 28%, then I turn it off and turn it back on and it will be 29%. Oh... and for those of you wondering
5 - This has happened both on a stock rom, rooted stock (although not like that would make a diff) and a custom rom ARHD. But still there is one last question...
6 - Why is there so much disparity on the issue? My theory is because this battery madness is so unpredictable you, you don't know when you get a normalized charge or an inflated charge. And lastly...
7 - I think it's gotta be a SW issue, why else would Nexus S owners be seeing the issue as well? (So that's good news... hopefully).
Soooo, that's my little rant. I think part of the problem is people are getting distracted by all these other theories with kernel drivers and etc because of the absurdly high Android OS issue (although in all fairness my theory could be more misdirection).
So why post? Well if people could try their luck validating/disproving my theory I would really appreciate it!
Here's what I'd like (and what I am going to do).
Charge your battery for an hour, if it charges really fast note the percentage.
Optional: Play with the phone for a while and see if it discharges quickly.
Do a battery pull, let it sit for a sec and put it back in and note the percentage.
If the percentage is significantly lower (10+%) start using the phone now and note the time to discharge.
Thanks!
EDIT: Also a good thing to mention, I am not disagreeing about the Android OS bug - I think that's also very real and something I have experienced as well. BUT if you look at the other battery thread you'll see a lot of people posting battery success images with high Android OS utilization. I think it could be an indication of multiple issues contributing to a negative experience.
Oh and I submitted a bug report to Google.
http://code.google.com/p/android/issues/detail?id=23311

I've also noticed crazy battery drop after reboots or pulling battery. Easily drops 10%+ at times. Reminds me of my great blackberries back in the day
Sent from my Galaxy Nexus using xda premium

all good here. i'm very pleased with the battery life.

while there may be issues with the stats, the wake times are real for some users - as well as the heat generated (indicating the cpu is working) when the phone should be sleeping.
There is no question there are either bugs in ICS that cause wake locks to get stuck, or badly written apps that keep it awake that didn't keep awake froyo/gingerbread.

Agreed on the wake lock. In fact I really should have quantified that in my original post - I too have that ridiculous Android OS utilization.
I updated my post - you make a good point.

Charged to about 21%. Pulled battery and rebooted and reported about 31%. Running ARHD.
EDIT: Pulled battery again and rebooted and reports 20%.

I realized mine was charging extremely slow so I decided to turn it off and let it charge faster. It was only at 48% when I turned it off but as soon as the battery indicator showed up with the phone off it appeared to be well over halfway charged, I would've guessed close to 75% but I didn't think to turn it back on and see..
edit: I did charge it fully with the phone off then wiped battery stats in cwm before rebooting into the OS after this. Since then it seems to be charging normally and reporting the correct battery level

To prove this theory, I think you should check the reported voltage of the battery and compare that to the percentage meter. Most battery apps/widgets use the old Android "battery info" screen to report this data. There very well may be a problem with the GN/ICS meter, but to be sure there has to be some constant to go back to.
These batteries drop like a rock from full charge to something like 87-88%, and again from around 37-38% to zero. It's just the battery technology, perhaps exacerbated by not having enough battery stats to adjust the % meter.
As far as I know, an app/widget that reports battery voltage will do so from the information being provided by the battery circuitry itself, so it's not subjective or adjusted in any way like a meter will be, making it a far better correlation point for the discussion.

djp952 said:
To prove this theory, I think you should check the reported voltage of the battery and compare that to the percentage meter. Most battery apps/widgets use the old Android "battery info" screen to report this data. There very well may be a problem with the GN/ICS meter, but to be sure there has to be some constant to go back to.
These batteries drop like a rock from full charge to something like 87-88%, and again from around 37-38% to zero. It's just the battery technology, perhaps exacerbated by not having enough battery stats to adjust the % meter.
As far as I know, an app/widget that reports battery voltage will do so from the information being provided by the battery circuitry itself, so it's not subjective or adjusted in any way like a meter will be, making it a far better correlation point for the discussion.
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I use current widget to tell me my voltage, as I don't pay attention to the meter. On a stock LTE battery, you should cap out at 4.203V

Voltage meter sounds like a reasonable way to approach the problem. I'm definitely not an expert on battery stats though - what should the voltages read? I know it caps at 4200mv, but what is the min?
Also how does mv relate to mah?

m0sim said:
Voltage meter sounds like a reasonable way to approach the problem. I'm definitely not an expert on battery stats though - what should the voltages read? I know it caps at 4200mv, but what is the min?
Also how does mv relate to mah?
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mv stands for millivolt which is a measurement of voltage. Examples you may have heard before are 9v battery, 110 volt wall outlet.
1mv = 1/1000 volt OR 1v = 1000mv, so you can see a mv is very small compared to a volt.
mAh stands for milliampere-hour and, in layman's terms, is a measurement of battery capacity, specifically how many hours a battery will last if the device it is connected to pulls a known amperage.
So, if a device pulls 500mA and the battery is rated 2000mAh, then generally the battery will last 4 hours (2000mAh/500mA). There are numerous other factors in the equation such as temperature, age of battery, etc. that can affect the battery life.

Battery Automatically Recharges without Plug in

Has anyone experienced this. I used my phone heavily for about 1.5 hours at which point it said that I had about 50% battery left. i then left it untouched and unplugged for about 8 hours overnight and when i picked it up int he morning it was at around 50% still and the battery details showed this. seems like after i stopped using it, the battery started charging rather than discharging until I picked it up again.
I'm on stock with an extended battery.
I'm not complaining, just trying to see whats going on.

I've seen this happen as well when going from heavy use to no use over night or when put in airplane mode.

should ask in the Q and A forum....not development....
not only is it the wrong forum...but you will get more answer

The reason for this is due to how the phone displays battery usage statistics. You phone will periodically check the phone usage and determine battery life based on your current usage amount. So if you talk on your phone for an hour straight, during the time your phone will figure how much battery you have left based on that usage. If you then don't use it for 8 hours, your battery level indicated by the phone can actually go up, or stay the same for a very long period of time. Thats why your battery will drop very fast when you start to use it when it has not been used for a while.

It looks like the SOC (state of charge) algorithm is using the derivative of current (consumption over time) in conjunction with the open circuit voltage, yet taking little regard to cell temperature.
As current consumption is decreased, the cell temperature will eventually decrease and the open circuit voltage will slightly increase. This is where the SOC difference comes from.
This is a common problem with any SOC algorithm that doesn't precisely factor in the cell temperature. With these lithium cells being as small as they are (compared to what's used in Automotive applications) trying to characterize the cell temperature characteristics would be like nailing jello to the wall.

akilestar said:
The reason for this is due to how the phone displays battery usage statistics. You phone will periodically check the phone usage and determine battery life based on your current usage amount.
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My thoughts are right along these lines. The phone is projecting your remaining battery life based on previous usage. It is forcasting what your usage will be and with no usage over a certain time period it is reporting negative numbers which send your patterns in a different direction.

Definitely feels temp related. I used mine heavily in a real bad signal area (Restaurant with a tin ceiling...) and it got really hot. I noticed battery life down to 48%. Put it near a fan to cool off and 5 minutes later it was at 65%.

Not positive on specifics, but it has to do with voltage fluctuating.

[Q] Battery Voltage and Current when Charging

Hello!
I've been keeping an eye on my battery's activity with Battery Monitor Widget just like I do with all devices, and after some months of using the HOX I am concerned about the following: I have noticed the battery shows 4218 mV when fully charged, which seems to be an ok value. However, I sometimes find it showing 86%, but already 4214 mV. The current also drops when it's over 80%, from the usual 600-700 mA, gradually to 200, then 100 and even less. I know this is normal when the battery gets full, but I am worried I have a damaged battery that only takes about 88% capacity. Has anyone else noticed this?
Thanks!

IMO battery monitor widget and most other such battery voltage/amperage monitoring apps are not accurate on the One X. I have got few unrealistic values with those tools especially when charging. Voltage should be 3700mV+ when fully charged, not 1218mV.

I'm sorry, I must have been thinking about something else. The values are 4218 when full and 4214 mV at 86%. I have modified the post now. I have also noticed the current when discharging is not quite accurate (it shows less when playing music then when doing nothing at all), so you think I shouldn't be worried about the battery?

asp2010 said:
I have also noticed the current when discharging is not quite accurate (it shows less when playing music then when doing nothing at all), so you think I shouldn't be worried about the battery?
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Yes, I have also noticed similar discrepancies, for example I sometimes get a higher positive mA rating when connected to USB port compared to the wall adapter (which is clearly wrong). Therefore I don't know if any of those readings are really accurate or not.

[Q]battery not fully charging

Hello.got xperia m before 4-5 days.its with cm11 and i got an issue with battery.when i charge my phone close i can see that it is 100% charged.but when i open it it drops to 95% fast. Same thing happens if i charge it open. When i replug the charger it goes to 99% normaly but after it takes much time to go 100%. Is this normal?i also try calibrating battery removing battery.bin and also tried removing battery for 10min.no luck at anything

AggelosGR said:
Hello.got xperia m before 4-5 days.its with cm11 and i got an issue with battery.when i charge my phone close i can see that it is 100% charged.but when i open it it drops to 95% fast. Same thing happens if i charge it open. When i replug the charger it goes to 99% normaly but after it takes much time to go 100%. Is this normal?i also try calibrating battery removing battery.bin and also tried removing battery for 10min.no luck at anything
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It looks like it has some wear. Because you're probably out of warranty by flashing another ROM, may be it's a good idea go searching for another battery. If I'm not mistaken, there are some 1900 mAh batteries arround compatible with Xperia M (the default one being 1750 mAh).
But you can try to turn airplane mode on, then go to Settings > Performance > CPU and setting maximum CPU speed to 486000, as well as the CPU governor to powersave, then checking the option to restore these options every boot. Level brightness down to the minimum.
Now, let it charge to 100%, disconnecting the charger, after. See if it drops. If it still dropping, it's battery wear. Of course, the time it lasts depends on how much time you spent with screen on and what tasks are you performing, i.e.: if you're playing Fruit Ninja right after disconnecting the charger, with medium brightness, it's not imposible to drain 7% right at the first three to five minutes.
Well, may you post a screenshot of battery usage graph?

prppedro said:
It looks like it has some wear. Because you're probably out of warranty by flashing another ROM, may be it's a good idea go searching for another battery. If I'm not mistaken, there are some 1900 mAh batteries arround compatible with Xperia M (the default one being 1750 mAh).
But you can try to turn airplane mode on, then go to Settings > Performance > CPU and setting maximum CPU speed to 486000, as well as the CPU governor to powersave, then checking the option to restore these options every boot. Level brightness down to the minimum.
Now, let it charge to 100%, disconnecting the charger, after. See if it drops. If it still dropping, it's battery wear. Of course, the time it lasts depends on how much time you spent with screen on and what tasks are you performing, i.e.: if you're playing Fruit Ninja right after disconnecting the charger, with medium brightness, it's not imposible to drain 7% right at the first three to five minutes.
Well, may you post a screenshot of battery usage graph?
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Well i put it last night and it charged 100% and battery drops normaly. I thing that this is happening only when i charge it closed...

Charging it closed? Locked?
Well, it's strange because sleep should save battery.
Anyway, looks like your battery has some damage. It's a good idea to take someone's battery to test it out, or bringing it to some place where they replace batteries (I know, it's a horrible english formulation, but back here, in our yellow and green country it does make sense, since there's a lot of Asians and Paraguyans selling all that stuff right in the downtown streets, but you'll have to check out for a place that can test it for you).
You may well take it to Sony, but they'll charge you for everything that they replace. Still, it's the best place to ask for a test. Not so much, here in my city, because store workers are, in general, a bunch of semi-cultured people who knows nothing about handset techinal aspects, just waiting for the time to take the bus and go home. Well, just sayin'... Good luck!

Ok.battery seems to work fine.phone charges to 100% and it holds 5h and 45min of gaming with low brightness.i charged it full,removed charger and i go to sleep.when i woke up (after 6h50min) phone was still 100%.i guess that the phone wasnt charging full cause of the way calibration i did by removing battery.bin....

AggelosGR said:
Ok.battery seems to work fine.phone charges to 100% and it holds 5h and 45min of gaming with low brightness.i charged it full,removed charger and i go to sleep.when i woke up (after 6h50min) phone was still 100%.i guess that the phone wasnt charging full cause of the way calibration i did by removing battery.bin....
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It happens. This morning I used my phone for 40 minutes after disconnecting it from the charger. Minimum brightness, CPU throttled to powersave/540 Mhz max. settings and it still managed to get down to 94%. It turned out that the GPS were turned on, for some unknown reason. I turned it off and back on, and it went working correctly (i.e. working only when wheater update required it). Indeed, the screen itself does suck a great amount of power, and the screen kept on for nearly 90% of this 40 minutes. So I got to correct myself, also and apologize for my over-sugestion.
Cheers!
P. Pinheiro

Looking for a mod to make the battery indicator more accurate

Ever since the March update, my Pixel 3 XL's battery indicator in the status bar has been horrendously inaccurate. This is really annoying, as it always shows as having 10-12% less battery than the actual physical battery charge. If it ever reaches 0% and shuts down, if I were to, say, boot into TWRP, I'd see I still have about 11% battery remaining. Across all the phones I've owned over the years, I've never seen such a severe battery level mismatch before. I've never seen greater than a 2% difference in any phone I've owned.
I use the Advanced Charging Controller Magisk module to regulate how much my battery charges. Charging your phone too much is proven to damage your battery over time, so I like to set ACC up so that my phone never charges past 41%.
I first noticed this problem when my battery would stop charging past 31%. After digging deeper, I found that the battery level produced by "dumpsys battery" (used by the status bar indicator) does not match the actual battery level, which can be read from a kernel control file at "/sys/class/power_supply/capacity."
As a side note, is your battery indicator also incorrect? Try checking it running these commands as root, and compare the values. Maybe this affects you too:
cat /sys/class/power_supply/battery/capacity
dumpsys battery
(The number you're looking for in the "dumpsys" command is the number next to "level." If it doesn't match, and it's less than what's written to the capacity file, then you also suffer from this issue).
I've asked the ACC developer what can be done about this, and apparently not much, besides having ACC "pretend" the battery is offset by a user specified battery level. But in my case, I would just be charging my actual battery to 51%, even though it would display as 41%, and I don't want to do that. I tried fixing it by clearing my battery stats, charging to 100%, and etc, and it actually made matters worse for me - the status bar indicator now remains at 12% less than the actual battery level. No matter what, this value appears to be linear - it doesn't seem to be any more or less correct depending on how charged the battery is. It's always 12% less, unless you get beyond 88%. Then the statusbar pretends to charge, even though a voltage monitor will show that it is not charging.
I can "force" the statusbar to read as the most accurate battery level by running this command in the background in a root shell:
while sleep 15; do dumpsys battery set level $(cat /sys/class/power_supply/battery/capacity); done
This manually sets the battery level via dumpsys according to what the actual battery level is. But this has some limitations.
I'm using a while loop because setting a value like this is permanent - if I don't either continually set it or unset it, my phone will think my battery level hasn't dropped below the last set value.
However, more importantly, setting a value via dumpsys disables monitoring of other battery stats, such as voltage, temperature, current, whether or not the battery is charging, the charge counter, and etc. Just running a script like that isn't a good solution.
So since I have nowhere else to ask, is there any kind of root mod or something that can be made to force the phone to use the correct battery level? I don't know why this started happening since the March update, but it is extremely annoying, and I'd like to put an end to it as soon as possible.
Any insights to mods or tweaks that can be done to fix this would be greatly appreciated.

so im at 5%, but in /sys/class/power_supply/capacity it says 0 .... not sure what's real anymore
I'm gonna charge up to 100% and see for myself what "full capacity" is like

and now i'm at 91% in status bar but 93% in that capacity file lol

If I remember correctly Lithium batteries actually last longer if kept above the 60% range and taken off the charger when they're completely full or maybe a few percent before. It's the lower end of the battery percentage that actually damages the battery if it's kept there for too long. The lower the voltage the higher the resistance in the battery, this is going to cause heat in the battery, so the way you're charging your battery is most likely damaging. I might be wrong but battery tech has changed over the years, and some old misconceptions still exist.
My guess about the amount of difference in the battery display vs percentage is to protect people from this reason. To keep them off of the lower end of the battery because it's damaging to the battery and under the wrong circumstances it could cause the battery to overheat.
Sent from my Pixel 3 XL using Tapatalk

superchilpil said:
My guess about the amount of difference in the battery display vs percentage is to protect people from this reason. To keep them off of the lower end of the battery because it's damaging to the battery and under the wrong circumstances it could cause the battery to overheat.
Sent from my Pixel 3 XL using Tapatalk
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While I can see that , i'm currently @ 100% in status bar, but 98% in the capacity file. and it won't go above that currently.
This kind of makes sense given how the battery jumps erratically from 100% to 98-06% too when discharging

masri1987 said:
While I can see that , i'm currently @ 100% in status bar, but 98% in the capacity file. and it won't go above that currently.
This kind of makes sense given how the battery jumps erratically from 100% to 98-06% too when discharging
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What are you calling the capacity file? Battery in settings?

Tulsadiver said:
What are you calling the capacity file? Battery in settings?
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this file > sys/class/power_supply/battery/capacity

So, just FYI, this is probably why i found charging it in TWRP to be the most accurate...
When i charge my phone up to 100% in twrp, i boot up phone, look at the capacity file and it reflects spot on what the status bar says, and it continues to do that throughout entire discharge.

superchilpil said:
If I remember correctly Lithium batteries actually last longer if kept above the 60% range and taken off the charger when they're completely full or maybe a few percent before. It's the lower end of the battery percentage that actually damages the battery if it's kept there for too long. The lower the voltage the higher the resistance in the battery, this is going to cause heat in the battery, so the way you're charging your battery is most likely damaging. I might be wrong but battery tech has changed over the years, and some old misconceptions still exist.
My guess about the amount of difference in the battery display vs percentage is to protect people from this reason. To keep them off of the lower end of the battery because it's damaging to the battery and under the wrong circumstances it could cause the battery to overheat.
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Click to collapse
The OP of the ACC discussion thread has some good links to studies done on Li-Ion batteries. It's a long read, but the summary is that you'll want to keep your temperatures as low as possible, and the battery itself between 30% to 80%. There are also some factors related to voltage that I don't really understand, but I do know that ACC manages the charging voltage to reduce strain while charging. The recommendation by the ACC developer for longevity is ~41%. That is within the 30% to 80% range, and I trust his judgement.
As for the other concerns in this thread, I don't think the difference in numbers serves any functional purpose other than to be annoying. It turns out that the one shutdown I had previously must have been a fluke, because now the battery in the statusbar will just sit there at 1% while the actual battery capacity ticks down, before forcefully shutting off at around 2% actual capacity. I don't even get the graceful "battery is empty, shutting down" message anymore.
Because the battery level reported by the capacity file is closer to zero than the statusbar one (simply because it shut down when that number was closest to zero), I'm inclined to believe it's the more accurate measurement. It's totally unrealistic to believe that the last 1% of the battery lasts as long as the previous 10%.
I can understand Google making the battery report a lesser number in order to protect the battery from the user, but that argument doesn't work if the phone just sits at 1% forever until it shuts down, which it has been doing for me. And the difference in numbers is just insane. Just today, the statusbar reported 2%, when the system reported 17%. A fifteen percent difference is absolutely absurd. I can understand a modest 3-5%, but this is just ridiculous.
I'm hoping there is a clever solution for this soon, or that the April update addresses it, because it's driving me crazy.

I tried this and the results from both commands were identical. I'm running the March update, rooted, and Kirisakura kernel.

Face_Plant said:
I tried this and the results from both commands were identical. I'm running the March update, rooted, and Kirisakura kernel.
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Thanks for letting me know.
This is so weird. Maybe my battery is just horribly uncalibrated?

ubergeek77 said:
Thanks for letting me know.
This is so weird. Maybe my battery is just horribly uncalibrated?
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Maybe it's time to start fresh with a full wipe/format and reinstall the March update? Maybe ACC is causing the issue? Have you tried Battery Charge Limit? That's what I use.

Why would you only charge your battery to 40%? I understand to prolong the life of the battery, but to what extent is going to do that.
You are shortening the amount of time needed between chargin. How much time does the battery last before you need to charge it again when you only charge it 40%?
If I am misunderstanding this, I think it would make more sense to keep the charge between 40%-80%.... Even if this is the case, how long does a charge last when you only use about 40% of it's capacity?

ubergeek77 said:
The OP of the ACC discussion thread has some good links to studies done on Li-Ion batteries. It's a long read, but the summary is that you'll want to keep your temperatures as low as possible, and the battery itself between 30% to 80%. There are also some factors related to voltage that I don't really understand, but I do know that ACC manages the charging voltage to reduce strain while charging. The recommendation by the ACC developer for longevity is ~41%. That is within the 30% to 80% range, and I trust his judgement.
As for the other concerns in this thread, I don't think the difference in numbers serves any functional purpose other than to be annoying. It turns out that the one shutdown I had previously must have been a fluke, because now the battery in the statusbar will just sit there at 1% while the actual battery capacity ticks down, before forcefully shutting off at around 2% actual capacity. I don't even get the graceful "battery is empty, shutting down" message anymore.
Because the battery level reported by the capacity file is closer to zero than the statusbar one (simply because it shut down when that number was closest to zero), I'm inclined to believe it's the more accurate measurement. It's totally unrealistic to believe that the last 1% of the battery lasts as long as the previous 10%.
I can understand Google making the battery report a lesser number in order to protect the battery from the user, but that argument doesn't work if the phone just sits at 1% forever until it shuts down, which it has been doing for me. And the difference in numbers is just insane. Just today, the statusbar reported 2%, when the system reported 17%. A fifteen percent difference is absolutely absurd. I can understand a modest 3-5%, but this is just ridiculous.
I'm hoping there is a clever solution for this soon, or that the April update addresses it, because it's driving me crazy.
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While I agree it's absurd if it in fact is showing a 15% difference, but where is the proof that such a thing is occuring?
I've read a few articles that talk in depth about lithium ion and the takeaway is to charge your device TO 75-80% and remove it at 30. Charging to 40% and completely discharging it is in fact damaging the OP's device and that's what I was trying to say.
Sent from my Pixel 3 XL using Tapatalk

superchilpil said:
While I agree it's absurd if it in fact is showing a 15% difference, but where is the proof that such a thing is occuring?
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I've already given proof. The proof is that the battery value produced by running "dumpsys battery" does not match the actual battery value, as read by the kernel, under "/sys/class/power_supply/battery/capacity." For clarification, the statusbar uses the value output by "dumpsys battery," which has been the incorrect value for me for almost a month now. SO's Pixel 3 XL is doing the exact same thing.
Further proof is that this offset doesn't serve any functional purpose. You would think that this kind of offset would be a way to protect the battery from the user, but that argument only works if the phone shuts itself down before the actual capacity reaches zero. That doesn't happen.
Instead, once the statusbar reaches 1%, it will just stay there indefinitely until the phone doesn't have enough voltage to keep itself on.
For example, let's say I'm monitoring the battery level in a terminal. When my statusbar says 2%, the kernel reads the battery as being 16%. It takes 10 minutes for the statusbar to reach 1%, and at the same time, the kernel battery reading will show 15%.
However, in a further 10 minutes, the phone does not shut off. Instead, the kernel battery reading will continue to tick down - 14%, 13%, ... 8%, 7%, etc - until the phone shuts off due to low voltage. During this time, the statusbar will continue to display 1%, despite the fact that the actual battery level is depleting.
No graceful shutdown, and the statusbar never reaches 0%. As such, I no longer see the "Battery Empty, shutting off" message where the phone shuts itself down gracefully.

I've kept my Pixel 3 XL updated with the latest updates and Kirisakura kernel. ACC (default settings) and my battery was doing fine until around the March update when I started a difference in reported battery level between the status bar and system that worsened and grew to 15% or more (I don't exactly remember). Also the status bar battery level would hang at 1% for a ridiculously long time. After uninstalling ACC and a several of charging cycles it got better (and the April update). Now my difference is 3%.

what happens if we delete that battery file? does it regenerate on it's own?

Got the same error with a Pixel 3, /sys/class/power_supply/battery/capacity is about 10% higher than dumpsys.

Is this why my phone shuts down at 14% battery level? I'll get a notification my battery is dying, check it, it'll be between 12-15% battery left, shut down 30 seconds later, and I can't reboot bc battery is dead. When I plug it in, then boot back up, it only says it is at 2 or 3%. I'm locked down bl because I thought maybe some root apps were messing with it, and I've even tried on q beta, but still early shutdown issue. Not really bothersome as I get 7 hrs or better screen on time, but it is curious....

Bryanx86 said:
Is this why my phone shuts down at 14% battery level? I'll get a notification my battery is dying, check it, it'll be between 12-15% battery left, shut down 30 seconds later, and I can't reboot bc battery is dead. When I plug it in, then boot back up, it only says it is at 2 or 3%. I'm locked down bl because I thought maybe some root apps were messing with it, and I've even tried on q beta, but still early shutdown issue. Not really bothersome as I get 7 hrs or better screen on time, but it is curious....
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I have a similar situation. It starts with 20-25%.
I think this started for me with q.
I wiped my device and flashed factory image to a/b slot. About 3 times .
How is your device going?
RMA is on the way....