Hi !
I have a nook HD+ which has been behaving strangely. Its battery life has reduced lately. I initially had problems with 'media' and 'SDcard' draining it quickly. But I was able to check that by formatting my SD card and deleting two 0 kB files in my internal memory.
However, the battery life, since, has not improved much. Moreover, I have started to see a few spikes in the battery charge chart (like the one in the pictures attached with this post) without having plugged the Nook in.
I am on CM 11 snapshot M8. I have already tried calibrating my battery by charging it to 100% and then removing batterystats.bin system file through PlayStore's 'Battery calibration' app, but the issue still remains unresolved.
Has anyone else faced a similar issue with her or his Nook ?
You cannot calibrate batteries in Android. Those silly apps just delete batterystats.bin and that is an Android file responsible for the statistics seen in your third screenshot. It gets deleted automatically when you unplug the charger at an almost 100% charge level, and it has nothing to do with the reported battery level!
The battery percentage as shown by Android comes from the kernel, the power management unit (PMU) driver to be more specific. The PMU, which usually is a separate chip inside the device, is responsible for monitoring, charging, and discharging the battery, among other things. There are many different PMU models, so this is highly hardware-dependent, and there most likely are no apps out there that can directly talk to all the existing PMUs to do something that's actually meaningful (which deleting batterystats.bin is not).
The only thing you can do is once in a while discharge the battery until the device turns off, then recharge it in one go to full capacity. That way, the PMU hopefully "calibrates" its battery monitoring by itself and should report more accurate state of charge values again. Measuring a battery's state of charge is rather difficult and not an exact science. Those percentage values are only estimates. So, the spikes you see on the battery percentage chart are a result of the imperfect method that is used to calculate the current battery percentage. Maybe this gets worse with aging batteries, I don't know. There's nothing really you can do, other than the complete discharge/recharge cycle you've already tried. Maybe a future firmware will come with a better battery percentage calculation method - but as I said, this is totally independent from Android, it's a low-level hardware and kernel driver thing.
Thanks a lot. A very informative post indeed !
Full battery charge/discharge cycles seems like the only solution then.
How will it affect the battery and its capacity to retain the charge though ?
To prevent any misunderstanding: you should definitely not discharge your lithium-ion based batteries to 0% all the time. Li-ion batteries live longer if they are kept between 40% and 80% charge. At 80% you won't get the full capacity / runtime, of course, but the battery will be able to endure more charge/discharge cycles that way. As I said, discharging to 0% followed by recharing to 100% should only be done occasionally, if you feel that the reported battery percentage has become too inaccurate. It probably won't fix the "ghost recharging" seen on the Nook and other devices. What probably happens here is that the battery's voltage is factored into the state of charge calculation. Li-ion batteries are usually charged to 4.2V per cell, which is "100%", and discharged to some arbitrary voltage, e.g. 3.5V, which would be considered "0%". Inbetween, the voltage curve is not linear. That is, 50% would not necessarily correspond to 3.85V (=(4.2+3.5) / 2). Also, the voltage depends on the power draw to some extent. If the tablet draws a higher current from the battery, the voltage will sag. If you then put the tablet into standby, reducing the current to a very small value, the battery voltage will recover and increase again a bit. This is what might cause those spikes (although they shouldn't be that large).
This and more can be learned on Battery University. And here's a source for the batterystats.bin calibration myth.
Thanks a lot Tzul. You have been very helpful !!
I may have to replace my battery soon. If the battery life does not improve, I guess I will have to buy a replacement battery from a third party replacement battery seller.
Related
Is it really necessary to charge my phone for 8 hrs before the first use? I just got my phone and i dont know whether or not charge for 8 hrs or just use it right out of the box. thanks guys!
It's not 'necessary', your phone won't brink if you don't do it.
However, if you condition your battery - charge for 8 hours on first use and then drain it until it's dead, and repeat 2 or 3 times, the battery will have a much better life and useage time (in my experience). This is because all batteries have memory, even ones that say they don't.
xconradx said:
It's not 'necessary', your phone won't brink if you don't do it.
However, if you condition your battery - charge for 8 hours on first use and then drain it until it's dead, and repeat 2 or 3 times, the battery will have a much better life and useage time (in my experience). This is because all batteries have memory, even ones that say they don't.
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Are you sure what you are talking able? Li-ion don't have memory effect. And if fact "A stand-alone Li-ion cell must never be discharged below a certain voltage to avoid irreversible damage." (quote: http://en.wikipedia.org/wiki/Lithium_ion_battery)
so its not necessary? im confused what did everyone else do when you first received your phone?
I work in the business... I'm sure.
First off, wikipedia is not the most reliable source. Second, your phone won't let you discharge your battery that far, it will shut off long before the battery gets that dead. Lithium Ion batterys can lack the 'memory effect' (effect being the keyword), but they do have memory.
Either way, no need to get up in arms about it. Just charge your phone up all the way, use it till the kaiser tells you to recharge, something like "Replace or recharge your battery to avoid data loss". It's like 10 or 15 percent. When you get there plug it in and charge it all the way up.
You arnt going to hurt your battery as posted above. Correct, if you get way too low you may have issues (why batteries go dead when they sit for a long time), but your kaiser won't let that happen. It will shut itself off first.
xconradx said:
I work in the business... I'm sure.
First off, wikipedia is not the most reliable source. Second, your phone won't let you discharge your battery that far, it will shut off long before the battery gets that dead. Lithium Ion batterys can lack the 'memory effect' (effect being the keyword), but they do have memory.
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Thanks for the info. If they don't have the effect, then what's that memory going to hurt us?
jackleung said:
Thanks for the info. If they don't have the effect, then what's that memory going to hurt us?
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Click to collapse
I'm not completely sure what you are asking... but...
The memory won't hurt you. True, you could probably take it right out of the box and use it however you wanted. The memory just helps tell the battery know when it's completely full (to switch to trickle charging if supported by the application), or when it's dead and in danger.
I'm too lazy to try and explain it, so I copied this... I should have refered to it earlier as "digital memory" earlier because it's not at all the same as NiCAD memory which is what most people understand - hope this clarifies.
From - http://www.batteryuniversity.com/parttwo-34.htm
"Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate." ...
"Batteries with fuel gauge (laptops, *cell phone {added by me}) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely. "
Hope this helps. There is a reason why the manufacturer recommends this. Battery performance as well as the accuracy of your gauge can somewhat depend on this sort of conditioning. This is the reason you may see your battery gauge go up after a restart, or when you charge your phone it may say 90% one second and 100% a few later.
Regardless, this is a crash course in batteries.
My xperia only lasts about a day with moderate internet usage, with moderate amount of necessary programs running (I ALWAYS close all apps after finishing).
Just a note, all my data connections are closed & tweaked to close after 2 mins of inactivity.
I heard that X1 batteries should last for ages.. at least 2 days to 4 days.
But I heard I need to flat out the battery, and then full charge it to 100%, followed by a soft reset. Apparently, this recalibrates the battery levels and users have reported battery life extend to 2 days to 3 days more!
So, my question is, if anyone has recalibrated their battery meters is..
1) After flatting my battery out, do I full-charge with the phone OFF or ON?
2) After I have fully charged, can I use PHM Soft Reset after windows boot-up?
Thanks.
I think you should buy another battery if you want more time.
My battery is down to about 50% on average after 8 hour work day. I have push e-mail and IM client and they always cause drain. 2-4 days would be if you didn't have consistent background services running.
As far as what you are saying about recalibrating the battery I think you are misinformed. Xperia has a Lithium-Ion or Lithium Polymer battery. Generally recharging frequently is better for it than doing a full drain. The type of full drain before recharge that you are describing was common recommended practice for Nickel Cadmium or Nickel Metal Hydride batteries. These could develop a "memory" in the battery which would dramatically reduce the amount of charge they would hold before they refused to charge.
If anyone has good evidence to the contrary I would love to be wrong, but I am pretty sure that with PUSH and IM there is no way to get a 1500mAH battery to last 3 days.
Also the radio you use and the area you are in (proximity to towers) can have a significant effect on your battery life.
charge it when it off for - + 1 Hr .
it will saty about 2 days
Hannigan174 said:
As far as what you are saying about recalibrating the battery I think you are misinformed. Xperia has a Lithium-Ion or Lithium Polymer battery. Generally recharging frequently is better for it than doing a full drain. The type of full drain before recharge that you are describing was common recommended practice for Nickel Cadmium or Nickel Metal Hydride batteries. These could develop a "memory" in the battery which would dramatically reduce the amount of charge they would hold before they refused to charge.
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Click to collapse
This is not absolutely true. It's true that Lithium battaries don't develop "memory" problems on their energy storing part, but they have a small circuit and this circuit is possible to develop the "memory" effect. This circuit is the one that decides that battery is full and cuts energy supply or informs about the percentage of the battery power remaining. This circuit for example is the reason that there is no point anymore on having the battery charged for 24 hours when you charge it for the first time.
IMHO you could try emptying the battery and charging it again when the device is off. Don't try to drain the battery completely as it could damage its power storing part.
i think i have the same problem about my X1. when i full charge my battery and after a few hours it goes 50% and sometimes my battery indicator says that i have 80% and after a soft reset the battery indicator says i have 20% weird...
So...I don't think this has been brought up here before, so I figure I'll be the dummy who asks. If I recalibrate (bump charge), and wipe battery stats, is it safe to assume that swapping out batteries (spares) will mess this up? I plan on picking up a spare battery, but wondered about this. Any input? Thanks in advance.
Not sure about the "bump" policy around here. but...........BUMP
Just charge the battery and use the phone. Don't get caught up in the whole wipe stats to create longer battery life craze.
I just swap batteries when needed about midday. I ignore the battery stats. They don't affect my use of the phone.
newter55 said:
Just charge the battery and use the phone. Don't get caught up in the whole wipe stats to create longer battery life craze.
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I understand that wiping stats does not "improve" battery life. but I have no problem believing that with a recalibrated battery (@ 100%), wiping stats will help the phone/battery meter "read" more correctly.
ua549 said:
I just swap batteries when needed about midday. I ignore the battery stats. They don't affect my use of the phone.
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Click to collapse
I thought so too, but I believe coupling it with a bump charge helped me a lot. I'll explain:
I recalibrated my battery about a week ago, (didn't know about wiping stats) I improved by about 3 or 4 hours daily, bringing me up to about 15 hours of use on a charge.
However,before I posted this thread, I did a recalibrate along with a wipe, then allowed the battery to drain and then a complete recharge. As of right now (27 1/2 hours later) I'm still looking at 30%
However, thats not why I started this thread though, I am simply wondering if swapping batteries back and forth will affect the stats and how the phone reads the state of the battery. (makes sense that it would I guess)
any input on THAT would be awesome, thanks in advance.
True. Unplugging the charger as soon as it shows 100% won't give you a full charge since it's not really accurate. I believe the charge complete notification is triggered by the charger shutting down. Not positive but I have noticed that can be triggered at varying times after 100% is reached.
Swapping batteries does mess it up but I can't say how much. There's always going to be a difference in charge between the two, and depending on different brands, a difference in the battery capacity and voltage at different % levels.
In short: The charge circuit measures amps going in and coming out, and remembers voltage levels at different times, so swapping batteries or using external chargers probably confuses it a bit.
Would it be possible to just create a separate batterystats file for the spare battery and swap out the files when the batteries get swapped out?
There was a post recently by a Google engineer, Dianne Hackborn (can't link yet, just google "Dianne Hackborn battery stats" and you should find it).
It explains that the battery stats come from data/system/batterystats.bin and are reset every time you unplug with a "relatively full charge." The file is reflected in the battery use screen.
It won't affect how much battery level is shown to you or how long your battery lasts.
Hi guys, my battery has sarted to read 100% after only a few minutes charging. The only way I know if it's charged 100% is to charge when the phone is off. I was wandering if anyone else has experienced this and knows how to solve it.
Thanks
Sent from my Optimus 2X using Tapatalk
The battery guage isn't the best. I rebooted my phone this morning and it went from 96% to 14%
About a minute later it was back where it should have been.
try to charge with the usb cable. i have this issue only with ac charger.
You could always try the common cure-all, deleting /data/system/batterystats.bin when at 100%, but I doubt it will help.
I also have this problem, it is since nightly 105 or something. Never had it before. I use the original charger, it read 100% after a few minutes of charging. When you unplug the device, it falls back to the real reading. So you never know when it is fully charged. I already deleted the battery stats in cwm, but it did`t help.
Seems like last 20 or so nightlys have battery issues......
Sent from my Optimus 2X using Tapatalk
Updating to nightly 117 seems to resolve the issue, although I don`t know which comment it would have fixed it.
it's ROM issues.. tried few ROM and these kind of bugs happened..
Try changing BaseBand and/or Ril
spica1234 said:
Try changing BaseBand and/or Ril
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That is bull****.
Sent from my GT-P1000 using Tapatalk
Note on Li-Ion cells / battery stats
Battery life is based on the voltage detected usually on the "3rd pin" which is standard on all Li-Ion packages as regulation. Now smartphone and all electronic devices that use these single (or multiple) Li-Ion cells usually make an estimate on battery life based on the degree of discharge based on the use you make of the device during the day. Having said this, there are 2 possible ways to show battery state of charge:
1) based solely on voltage. Full battery reads 4.2V, dead will be below 3.3-3V depending on vendor. However this means that device on-time is tighly connected to how much apps you run/screen/wifi/3G usage for ex.
2) based on voltage AND usage statistics. Software monitoring will store battery statistics in a file and use them to update the battery guage accordingly so battery charge status reflects more averagely the time you have left based on your daily usage habits and battery freshness.
If you delete the battery satistics file and you still get erratic readings, either there is a software bug in the battery guage integration software readings or you may have a problematic battery cell. The simple way is to swap batteries and see if the problem is gone or not.
Note on Li-Ion cells: the cell's have a limited number of charge-discharge cycles meaning the more you reach complete discharge before charging the shorter their life span. Better charge your cell(s) everytime you can which will increase their lifespan. Avoid overheating the cells which will also decrease lifespan. If heavily using the device, keep it powerer on usb or external charger.
My XT1092, recently got updated to Lollipop i.e. Android 5.0
Two of my battery runs, starting from 100% full charge came down to like 5% and the phone shut down automatically as if it was 0%
Also on a side note, i did not put any mode on the battery saver mode for those two runs.
Now to test it, i kept my battery saver to start at 5% but i am not sure if it will run at 5% or just shut down
Anyone got an idea/solution for this issue ??
P.S. Even Motorola care chat, does not have an answer, all they said is to keep my phone in safe mode for a day and check it out....
Mine just did this the other day. When I pressed the power button it showed the battery with a little red fill and a huge yellow triangle with an exclamation mark in it. Also happened last night.
I have also had the same issue xt1092 and on lollipop.
well...
yea man, so the thing is motorola support said that, keep ur phone in safe mode for a day and recheck the issue...
so idk... :/
i am checking my battery use and for now i have kept my battery saver on 5% so i hope it starts on battery saver itself.. rather than shutting down...
My XT1095 does the same thing. Really annoying! Its really lying to you about how much battery is left if its going to do that. I just know that if i'm going below 10% i better run to find a charger ASAP!
M3drvr said:
My XT1095 does the same thing. Really annoying! Its really lying to you about how much battery is left if its going to do that. I just know that if i'm going below 10% i better run to find a charger ASAP!
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it is quite misleading to say the least..
i did not have this issue with KitKat though..
might be a lollipop thing only
I'll join this list. Really annoying, and never happened on 4.4.4
I've never let my battery get that low honestly, but...
Keep in mind that your battery percentage is completely an estimate. Battery capacity is measured in mAh, but there's no way to measure the current charge capacity in mAh of a battery. The only way to do so would be to run all of the power out of the battery and record the power over time, but then you'd have a dead battery. As a result, the system estimates your remaining battery capacity as a percentage based on the current voltage of the battery. But that can be different depending upon how quickly you've drained the battery and other factors.
So, Android has methods built-in which automatically calibrate the battery, but they only work properly if you fully charge and discharge your device on a regular basis. A battery starts off weak, then it gains strength after a few charging cycles, finally over time it peaks and then begins to taper off as far as battery life goes.
You've likely not taken your device to 0% for a while. The android solution is to fully discharge and recharge your battery a few times to allow it to recalibrate. Slow charging is the best for recalibration. Plug it into a computer for 500mAh charging rather than using a charger. Chargers can charge quicker(1.5A) but do not allow the device to calibrate as well due to the high amperage.
So, just use your device and let it drain fully, and charge fully on a computer USB port and it should recalibrate itself.
InspectifierWrectifier said:
So, Android has methods built-in which automatically calibrate the battery, but they only work properly if you fully charge and discharge your device on a regular basis. A battery starts off weak, then it gains strength after a few charging cycles, finally over time it peaks and then begins to taper off as far as battery life goes.
You've likely not taken your device to 0% for a while. The android solution is to fully discharge and recharge your battery a few times to allow it to recalibrate. Slow charging is the best for recalibration. Plug it into a computer for 500mAh charging rather than using a charger. Chargers can charge quicker(1.5A) but do not allow the device to calibrate as well due to the high amperage.
So, just use your device and let it drain fully, and charge fully on a computer USB port and it should recalibrate itself.
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Click to collapse
While it does help the calibration, it's very bad for your battery to do this deep discharge multiple times.
raptir said:
I've never let my battery get that low honestly, but...
Keep in mind that your battery percentage is completely an estimate. Battery capacity is measured in mAh, but there's no way to measure the current charge capacity in mAh of a battery. The only way to do so would be to run all of the power out of the battery and record the power over time, but then you'd have a dead battery. As a result, the system estimates your remaining battery capacity as a percentage based on the current voltage of the battery. But that can be different depending upon how quickly you've drained the battery and other factors.
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Sometimes you don't have a choice about letting battery drain get that far.
But regardless, its most definitely an issue with lollipop. Uncountable android devices, and this is the first time I've ever experienced this issue. Happens religiously at 5%. So its never happened before on any device I've used, including this moto x pure on KitKat, and it always happens at 5%.
If it were a true calibration issue, one would think it'd happen at different percentages. However I'm certain this is a bug.
qwerty12601 said:
Sometimes you don't have a choice about letting battery drain get that far.
But regardless, its most definitely an issue with lollipop. Uncountable android devices, and this is the first time I've ever experienced this issue. Happens religiously at 5%. So its never happened before on any device I've used, including this moto x pure on KitKat, and it always happens at 5%.
If it were a true calibration issue, one would think it'd happen at different percentages. However I'm certain this is a bug.
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Click to collapse
I understand that you don't always have a choice, I just meant that I have no insight as to the possible bug since I've never experienced it. And to clarify, it's not really a "calibration" issue, it's a matter of there is no way to accurately measure the charge of the battery.
Honestly, Google could have even implemented this intentionally in order to prevent damage to the battery from a deep discharge.
raptir said:
I understand that you don't always have a choice, I just meant that I have no insight as to the possible bug since I've never experienced it. And to clarify, it's not really a "calibration" issue, it's a matter of there is no way to accurately measure the charge of the battery.
Honestly, Google could have even implemented this intentionally in order to prevent damage to the battery from a deep discharge.
Click to expand...
Click to collapse
But android has been completely accurate in the past. Right down to 1 single percent.
And there's no way google implemented this as a safety feature. If they were legitimately trying to do this, they'd just have the battery monitor read less than actual capacity as to not confuse the operator.
As well as they have what they believed to be a big feature, "battery saver" which has the option to activate at 5%. So them killing your phone at 5% intentionally doesn't hold water.
qwerty12601 said:
But android has been completely accurate in the past. Right down to 1 single percent.
And there's no way google implemented this as a safety feature. If they were legitimately trying to do this, they'd just have the battery monitor read less than actual capacity as to not confuse the operator.
As well as they have what they believed to be a big feature, "battery saver" which has the option to activate at 5%. So them killing your phone at 5% intentionally doesn't hold water.
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No it hasn't. It may not have shut down until after it read 1%, but it has not been accurate because there is no accurate way to measure the current charge of a battery.
http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge
The fact that it consistently shuts down at 5% does seem like a bug, but it's a very odd bug since it seems like there would have to be some code to specifically tell the phone to shut down.
raptir said:
No it hasn't. It may not have shut down until after it read 1%, but it has not been accurate because there is no accurate way to measure the current charge of a battery.
http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge
The fact that it consistently shuts down at 5% does seem like a bug, but it's a very odd bug since it seems like there would have to be some code to specifically tell the phone to shut down.
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Click to collapse
Every android device I've owned, probably 12, including the 3 still in service with me (moto x before lollipop, nexus 7, nexus 4) all have accurate battery meters right down to 1%. Now are they adjusting on the fly and lowering/raising battery percent to accurately match calculations? Probably. But it adjusts to where the battery meter will read down to the very last percent. No surprises.
The whole point of this thread us that some moto x pures are shutting down at 5%. Maybe the battery really is at 0%, maybe its at 5 or 10%, but its a "bug" that the phone is shutting off at 5%. Its rather a flaw in on the fly calculations where its not accurately adjusting at lower percentages, or a software flaw. But it's a bug either way. That's the complaint here.
raptir said:
Honestly, Google could have even implemented this intentionally in order to prevent damage to the battery from a deep discharge.
Click to expand...
Click to collapse
That is was Microsoft did with their Surface tablets, you can change it, I have mine set to power off at 10%
raptir said:
While it does help the calibration, it's very bad for your battery to do this deep discharge multiple times.
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Click to collapse
Wrong. this is the recommended way to use every mobile phone battery. A full charge and discharge is called a cycle, and cycles are how battery lives are rated.
InspectifierWrectifier said:
Wrong. this is the recommended way to use every mobile phone battery. A full charge and discharge is called a cycle, and cycles are how battery lives are rated.
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Please don't just post "wrong" without anything to back it up.
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Table 2 provides details as to why what I said is correct. A 50% discharge will not degrade to 70% capacity for 3-4x as many cycles as a 100% discharge. That amounts to up to double the useful life of the battery assuming your usage stays the same.
InspectifierWrectifier said:
Wrong. this is the recommended way to use every mobile phone battery. A full charge and discharge is called a cycle, and cycles are how battery lives are rated.
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Click to collapse
Have fun killing your battery very quickly by fully discharging all the time
raptir said:
Please don't just post "wrong" without anything to back it up.
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Table 2 provides details as to why what I said is correct. A 50% discharge will not degrade to 70% capacity for 3-4x as many cycles as a 100% discharge. That amounts to up to double the useful life of the battery assuming your usage stays the same.
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Click to collapse
Mobile device batteries are designed to be "fully" depleted. They are software controlled. You will never discharge a properly controlled battery 100%. This is why your device still has power to turn on and tell you that the battery is too low to turn on.
There are always exceptions to the rule. However, mainstream devices will almost always keep the battery at a safe level.
You cannot use a single chart on all lithium ion batteries. In fact, every one is different due to chemical and annode/cathode changes. This is why every battery has its own MDS for shipping purposes.
The small changes to batteries cause them to react differently to different usage patterns. When designing a battery these reaction patterns are supposed to be accounted for in the battery calibration.
A key engineering principal: a device should never be capable of destroying itself. Full discharge is normal operation for most devices.