Calibrating battery to preserve capacity - General Questions and Answers

Hello. I've read some posts, tried some apps but never found what exactly I need. So there's a thing: let's say my phone's battery capacity is 2900mAh. Is there a way to calibrate my battery to put, let's say, 200mAh to reserve? So when the battery is charged to a 100%, it would actually be charged only to 2700mAh and would stop charging. This way battery would get less voltage that damages it and would have longer lifetime.
I know that I can download apps that notify me when battery is charged to wanted percentage, but it's not always the most comfortable choice on many occasions.
All the topics, apps about battery calibration are to calibrate 100% to 100%, when I actually want 80-90% to be shown as 100%.

Related

The truth about lithium-ion batteries(Charging & Battery Stats)

Firstly.... go here and read this -
http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
The battery is fully charged when it is at 4.2 Volts and fully discharged at some predefined voltage (Lets say 3 volts).
The phone can measure these voltages directly from the battery. To see the voltage of your battery type *#*#4636#*#* into your phone and go to battery information.
If all that is so then what is the point or need of "recalibrating" and deleting battery stats and all that.
It seems logical to me that battery stats is just the place where your battery usage history is stored and nothing else.
Can someone confirm this or convince me otherwise?
(I rotate between 3 batteries and cannot grasp the idea that my phone can't consistently measure the charge level of the battery and operate accordingly.)
Measuring the Voltage to get the charge level is not very accurate, and has to be done with no load on the battery (that is, when its not in your phone).
So the phone has to count "energy used from"/"energy stored in" the battery for an accurate display. (called "Coloumb counter")
Did some test
I did a test on new a battery a while ago. Measure voltage when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The voltage showed on the phone using SystemPanel app is quite accurate with 0.04V margin of error. Most smart electronic measure lithium battery capacity according to the remaining voltage. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
Yet again how is this android development.
Sent from my GT-I9000 using XDA App
xufos said:
I did a test on new a battery a while ago. Measure current when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The current showed on the phone using SystemPanel app is quite accurate with 0.04V error margin. Most smart electronic measure lithium battery capacity according to the remaining current. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
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Click to collapse
Thanks for that, but you were actually measuring the Voltage, not current (Amperes).
In any case, for laptop Li-ion batteries there is normally a capacity counter (Coulomb counter) that reports the capacity in terms of mAh (milli-ampere hours). It can normally report the remaining capacity, maximum capacity, design capacity, and can be used to measure the *actual* power drain (in terms of Watts).
I wonder if Android has APIs that let apps access that kind of information?
Not really sure about this, but:
Phone seems to measure both voltage & discharge speed, "predicting" remaining charge.
It happens that after a flash battery indicator jumps to a higher value (not compatible with the couple of minutes of dc connection it had), and fall to a way too low value after any battery intensive task (a few minutes of audio call are enough), once more not compatible with the real usage.
I should inspect android code to be shure of this, but I suspect batterystats.bin is used to keep track of battery usage and to this sort of prediction, while a firmware flash seems to mess somehow the measurement.
Edit: this is based on my direct experience, even if on just "empirical" tests. I'll take a look to code asap
'mkay, battery talk... always interesting to see what people make of this.
Let's help out all the misunderstandings here and start with the basics
First of all: read the basics on Li-ion batteries:
http://electronics.howstuffworks.com/lithium-ion-battery.htm
second:
you DON'T measure your voltage when your battery is disconnected. Because it will rise to the normal values of the battery after a while. When you connect it, and use it, the voltage will lower. Compare it to a garden hose. if you let water run out, the presure drops and water starts flowing (presure is voltage, flowing is the current). If you measure the presure when there is no water running, the presure will always mount to the default value, even if there is "not much water left in the tank". But when it starts running again, it could very well run out very fast. So in comparison: voltage says something, but only when you "use" it.
Third:
When a battery ages, it's characteristics change, it will be full... and then all at once, empty. It's not linear. So calculating the capacity is always a bit "guessing". (compare it to stones in your water tank... they don't give you water, the tank doesn't change, but all of a sudden, you're out of water).
conclusion:
capacity of a battery is a very tricky thing to do, it's a combination of voltage, current, age... so the best way to determine capacity is by using the history of the battery as the "guide" to the future. Resetting the battery statistics will remove that history and your phone will have to "learn" it's behavior again. If you don't reset your stats, your values will become more reliable over time (depending of course on the time the stats are kept )
For those who speak dutch, i put a complete battery description/howto/misunderstandings post on www.modelbouwforum.nl (search for posts of "harrydg")
If there are more questions or so, just ask, i'll try to help out as much as possible...
wow harrydg that's great explanation, wish you were my physics teacher back in high school
someone add this post to the main FAQ!
I just wanna write it in a simpler way:
You've access to the battery stats from the kernel. And of course its current consumption which is measured not voltage. Voltage doesn't tell all that much. During high draws your voltage (at the battery level) can fluctuate quite a bit.
There's a regulator (or probably a bunch of them) get a stable voltage no matter what the input voltage is (well, still it has to be in the 3.3/5v range probably else the regulator burns)
Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity.
Not only the battery capacity changes from battery to battery but it also changes during the life time of the battery.
The *only* way to calibrate the battery, is to delete the stats, have a fully charged phone and let it drain out the battery until it turns off. That way the kernel will measure for example 1457mah used until it ran out of juice, and that's your battery capacity then. Having the full capacity allows the kernel to give you a rather precise estimate of your current battery status (eg "80%" that you see on the top of the screen) (of course the actual calculation is a bit more complicate but that's the basics)
If calibration stats storage is changed for any reason (probably kernel upgrade or just a whacky samsung implementation that gets corrupted for some reason) you need to delete it and make a new one to recalibrate.
If you want to make it simpler, make it at least correct...
"Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity."
First of al, it's mAh, which means milli ampere hour, NOT per hour, that would be mA/h, which it is not.
mA is milli ampere, which is a current
there is a significant difference between the 2.
the first is "capacity"
the second is "current"
it's like a bottle. The capacity is 2l and you pour at 1l per minut...
so... make it simple please...
My guess is, that android is measuring the known min and max by the battery reported values, stores them and calculates the percentages.
So it is device and battery independent.
harrydg said:
If you want to make it simpler, make it at least correct...
"Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity."
First of al, it's mAh, which means milli ampere hour, NOT per hour, that would be mA/h, which it is not.
mA is milli ampere, which is a current
there is a significant difference between the 2.
the first is "capacity"
the second is "current"
it's like a bottle. The capacity is 2l and you pour at 1l per minut...
so... make it simple please...
Click to expand...
Click to collapse
Sorry a typo and no caps deserve heavy flaming
bilboa1 said:
Sorry a typo and no caps deserve heavy flaming
Click to expand...
Click to collapse
hehe, sorry for the rant, but if you want to put it simple, make sure the terminology and abbreviations are correct. If not, people will take over the mistakes and conversations will go totally wrong because of misunderstandings...
Thanks very much for the feedback guys. It makes more sense now.
It's using batterystats to get familiar with discharge rates in order to give an accurate estimation of remaining charge and a prediction of when it will run dry.
Can it misreprasent these values and forcibly power down the phone when there is still charge remaining?
And likewise can it stop the charging process prematurely, estimating the battery to be at 100% charge when it is lower?
Is this the reason to recalibrate?
Heres one thing what I noticed about the battery stats, some say deleting it fixes the guage and does not really recalibrate the battery, I really doubt there is a way for end users to do that, even if you never delete the battery stats bin and your drain is pretty fast, it significantly slows down when your battery hits around 25~35, the lower the power on the battery the more accurate it can be represented regardless of the calibration. This is applicaple for the SGS only.
Now it comes to the question..
If the phone create battery stats every time the phone reboot, then when is the best time to delete and the best way to calibrate?
This is what I normally do..
..delete stats at 5%, let it run dry til it turn itself off, dont turn on but connect the charger til it fully charged. Turn phone on and ill have fully charged battery along with fresh stats.
Is this correct?
vosszaa said:
Now it comes to the question..
If the phone create battery stats every time the phone reboot, then when is the best time to delete and the best way to calibrate?
This is what I normally do..
..delete stats at 5%, let it run dry til it turn itself off, dont turn on but connect the charger til it fully charged. Turn phone on and ill have fully charged battery along with fresh stats.
Is this correct?
Click to expand...
Click to collapse
On the SGS theres no real point in deleting it, unless you dont really wanna see the battery go down to 35% and stay there for a while, how ever busted your battery indicator is it gets very accurate as the lower it goes.
I never found batterystats made any difference. What did make a difference is the rom or kernel, what widgets, lagfix e.t.c
If you get more than 1% battery drain per 5hr standby then something is wrong
Sent from my GT-I9000 using XDA App
android53 said:
I never found batterystats made any difference. What did make a difference is the rom or kernel, what widgets, lagfix e.t.c
If you get more than 1% battery drain per 5hr standby then something is wrong
Sent from my GT-I9000 using XDA App
Click to expand...
Click to collapse
I find that conclusion quite flawed.
First of all, what's your definition of standby?
3g on? Wireless on? Autosync on? There are also noticeable differences between different firmwares and between 2.1 and 2.2.
In addition, most people are reporting somewhere around 1% per 1 hour standby or 1% per 2 hour standby, which it what I have been experiencing as well. Sometimes, apparently for no reason, it can drain faster than that, maybe 1% per 0,5 hour or more. I think this might be some widgets fault.
1%/5h standby 3g no sync
i get 1%/2h with data and sync
Depends on your reception, im just basically saying if your losing say 8% battery overnight or more then something is wrong unless your polling several push email accounts

Useful Battery Information and Calibration

Here is some information that should be useful to everyone in one way or another if not then you should have told us your secret months ago. lol
A Li-ion batteries life is on a time clock from the day it's produced and how it is used, maintained and the number of cycles it goes through reduces it's life. Even when not being used at all the clock is ticking and life is shortening.
So if any of you are like me I know many of you are far worse than me when it comes to the amount of stress put through it with flashing and extreme general use. Hopefully this will shed some light for us as to what we can do to try and prolong the life of our batteries.
The majority of the following information is from the book “Batteries in a Portable World – A Handbook on Rechargeable Batteries for Non-Engineers” (2nd edition) and Battery University™
Special thanks to the books author and sponsor of Battery University™,
Isidor Buchmann
CEO and Founder, Cadex Electronics Inc.
How to Prolong the Life of Li-ion Batteries
Battery wear-down on lithium-based batteries is caused by two activities: actual usage or cycling, and aging. The wear-down effects by usage and aging apply to all batteries but this is more pronounced on lithium-based systems.
The Li-ion batteries prefer a shallow discharge. Partial discharges produce less wear than a full discharge and the capacity loss per cycle is reduced. A periodic full discharge is not required because the lithium-based battery has no memory. A full cycle constitutes a discharge to 3V/cell. When specifying the number of cycles a lithium-based battery can endure, manufacturers commonly use an 80 percent depth of discharge. This method resembles a reasonably accurate field simulation. It also achieves a higher cycle count than doing full discharges.
Simple Guidelines
Charge the Li-ion often, except before a long storage. Avoid repeated deep discharges.
Keep the Li-ion battery cool. Prevent storage in a hot car. Never freeze a battery.
Avoid purchasing spare Li-ion batteries for later use. Observe manufacturing date when purchasing. Do not buy old stock, even if sold at clearance prices.
Hints to long battery life
3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is reduced capacity.
The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion).The lower charge current reduces the time in which the cell resides at 4.20V. It should be noted that a 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage up and forces it into the voltage limit prematurely.
Memory Myth or Fact?
Lithium batteries are not affected by memory, but the chemistry has its own peculiarities. Current inhibiting pacifier layers affect them through plate oxidation. This degenerative effect is non-correctable on a lithium-based system
Calibration
A more serious issue is maintenance requirements, better known as capacity re-learning. This procedure is needed on a regular basis to calibrate the battery.
Why is calibration needed?
The answer is in correcting the tracking errors that occur between the battery and the digital sensing circuit during use. The most ideal battery use, as far as fuel-gauge accuracy is concerned, is a full charge followed by a full discharge at a constant 1C rate. This ensures that the tracking error is less than one percent per cycle. However, a battery may be discharged for only a few minutes at a time and commonly at a lower C-rate than 1C. Worst of all, the load may be uneven and vary drastically. Eventually, the true capacity of the battery no longer synchronizes with the fuel gauge and "a full charge and discharge are needed to ‘re-learn’ or calibrate the battery."
How often is calibration needed?
The answer lies in the type of battery application. For practical purposes, a calibration is recommended once every three months or after every 40 short cycles.
What happens if the battery is not calibrated regularly? Can such a battery be used in confidence?
Such a battery is able to function normally, but the digital readout will be inaccurate. If not corrected, the fuel gauge information simply becomes a nuisance.
Just Tell Me WTF I Should Do!
Charge your battery as often as possible, partial discharges are actually better for your battery
Once your battery is charged to 100% avoid leaving it plugged in any longer if you are not using a OEM charger.
Your battery should never get hot from charging if it does this is a sign it may be damaged.
If fuel gauge starts acting up calibrate your battery.
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
There is so much more that it's mind boggling but I think this covers the main parts and beyond for everyone. So far it appears that the bump method is not necessary nor are the numerous other steps.
I can only laugh when I think that the reason the method of calibration I was using was actually working is due to the fact that the "wipe batt stats, drain battery completely and charge to 100%" is basically the last step and all that is essentially needed.
3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm
darkamikaze said:
3 hours? That's it? I thought whenever I charged from empty to full when it's off it's longer.. I should time it.. hmm
Click to expand...
Click to collapse
I removed the time completely since some may vary. But the 3 hours is how long it should take to charge on a standalone battery charger. So rather than confuse or have questions it's better without it.
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Battery Stats
Since this is the first time i had a really good battery life. I would like to share it with everyone. Please see the attached screen shots.
I am using Darky's 9.1 with SuckerPunch's 1280/500 Kernel and TLJL3 modem.
I hope this will help anyone trying to get more battery life out of their Captivate.
Thanks,
CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Click to expand...
Click to collapse
Thanks Curious appreciate it and thanks for the additional info.
I had some other random thoughts about the calibration because I keep seeing so many posts daily.
For example "I installed a new kernel 15 minutes ago, recalibrated and the battery drain is horrible." or "After a few charges it lasted longer."
I don't think people get the idea of calibration. Recalibrating determines the capacity of the battery to convert to a % full gauge. To do that you need to fully charge until the "Battery full. Unplug charger." notification, and not rely on the display and unplugging as soon as it hits 100%. That's the inaccurate display that you're trying to calibrate.
Think of it like having an opaque container and a teaspoon. You think the container can hold 100 teaspoons, so you stop filling at 100. All you can get out of it is 100 until you try to fill until it tops off and then count how many come back out.
The phone works the same way. It has an ammeter that monitors the charge current and drain current from the battery from the time you unplug it until it shuts off and remembers that total as the capacity. Unless it's recharged in the middle which voids the data.
After that full discharge, it should stay pretty accurate even with partial discharges. At least until the next rom/kernel flash which wipes it out. At that point (I assume) it uses a simple voltage level and some relative amps drawn to display the gauge, instead of the smarter method of keeping a constant value of mAh by adding when charging and subtracting when draining to know exaclty how full the battery is.
CuriousTech said:
Nice work!
Charging a 1500mAh battery at 500mAh for example will take 3 hours. The Captivate charges at 2 levels though depending on if it's USB (500mAh max for charge + phone use) or a charger (whatever it says on the charger up to ~1200mAh) so it can probably get done in under 2 hours.
The phone charges to 4.23V and stops charging when full but continues to run on external power, and shuts down at 3.500V where it only consumes current to monitor the power button.
Just for reference.
Click to expand...
Click to collapse
hm. so if the phone switches to external power when the charge is full, is it okay to leave my phone plugged in once it's done charging? or is it just the fact that the battery is holding a full (4.2V) charge for a long time that's bad for its health?
in any case, useful post! i knew there were ways to preserve the life of li-ion batteries, but was never well-versed on the details.
Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.
Which is it that wipes the battery stats, ROM or kernel? or is it both?
CuriousTech said:
Yes to both. Once the battery is fully charged, the charge circuit stops completely. It doesn't even need to trickle charge, so leaving it plugged in doesn't hurt anything.
Once the charge is complete the voltage isn't being held at 4.20V so it can come back down a little. I think BatteryUniversity generalizes becuase there have been many different designs over the years that weren't as good as what we have now, and some may have trickle charged their Li-Ions which shortens the life.
Click to expand...
Click to collapse
One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.
zerkai said:
Which is it that wipes the battery stats, ROM or kernel? or is it both?
Click to expand...
Click to collapse
Both. The first thing in a ROM flash script is to format all the partitions, so that means the batterstats.bin file is erased. When flashing a new kernel the file gets reset by some other means. No idea what. It could be CWM.
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?
iNFRiNGE said:
One word of caution though is to ensure that you are using an OEM charger. Battery University recommends that you unplug once capacity is reached but perhaps this is a general statement for Li-ion batteries as you state.
Click to expand...
Click to collapse
What happens when you introduce the variable of occasional car charger use?
Sanctus Peregrinus said:
Yeah but how the f^$% do I calibrate my battery?
Charge phone up and then delete your battery stats.
Unplug your phone from your wall charger and let your battery drain all the way down until phone shuts off.
While still off charge phone to 100% and then boot up as normal.
My noob question is, how do you delete the battery stats?
Click to expand...
Click to collapse
the file is located at /data/system/batterystats.bin . you'll need a file browser with root access (i use root explorer, a paid app). make sure you mount the storage as read/write or you won't be able to delete the file.
after that, reboot your phone and it will rebuild the batterystats file.
***disclaimer: be careful doing this. if you delete a crucial file, you risk messing up or bricking your phone. such is life.
Nice write up with alot of interesting information. I have never calibrated my battery but will have to try it out. Thanks for posting.
Sent from my SAMSUNG-SGH-I897 using XDA App
I'm not positive of this, but I don't think batterystats.bin holds any battery capacity or health info. I was looking at BatteryManager and it looks like a database of processes and what they use only. But there is info somewhere that gets lost easily, which is the capacity and current amount consumed.
I've been skipping the delete of that file (using CWM) and have noticed that it recalibrates fine anyway. This coming from the point of dropping just after unplugging, which is a good indication that the info is gone.
It doesn't matter if you use a car charger, USB, or AC. The phone has the actual smart charger in it, the external connection is just the power supply. The chip inside regulates and monitors the charge.
So think of it this way. The charger knows when the battery is empty or full, and measures what goes in and comes out. So to know the capacity, it has to go from full to empty. That's really all there is to it. Just wait for the real "Battery full" before unplugging.

[Q] Battery percentage display

I have my captivate running 2.3.3 mosaic III ROM the battery life is excellent with a little help from SETCPU but when it fully charges the phones says the battery is full but when i unplug it the battery percentage display says it is at 98% did a battery stats wipe. Just wondering do i need to calibrate my battery also to fix the tiny little problem. by the way i fail to mention running Purple-licious ginger style theme. This is the only issue I'm having
not every battery has the same capacity, 2 oem batteries either.
there is a 2% difference between your batteries.
if you calibrate to the lower battery, the other will show 100% when you put it in, though in comparrison it would actually be 102% ....
its not worth worrying about.
i have 4 batteries i play with... 2 oem and 2 extended... now that confuses the phone!
this is a normal behavior by samsung.
Fully discharging and recharging your battery over the course of a few days should calibrate it to your liking, however Samsung does have a little feature to prevent damage to the battery by overcharging. This is normal and should be of no worry to you as long as you are getting decent battery life.
You can also try charging to full, removing cable and shutting down phone, then charging while off until the battery says 100%. Repeat three times and wipe battery stats.
Hope this helps.

[Q] The best way to calibrate a new akku?

Hello Guys, i bought a new mugen akku and dunno what´s the best way to calibrate it.
There are a few things that are confusing me:
1.Mugen Instructions: "Never drain battery to 0%"
(but that´s required for calibration, isn´t it?)
2.the battery got its full power after a few charges/discharges
(so would it be better to wait to calibrate the akku when it got its full power?)
So finally, should i wait with calibration or do it at the beginning? I think one time is necessary to let it go down to 0%.
So what are your advice?
thx in advance, l-viz
The way I calibrate mine is to discharge it completely so it turns off by itself (normally happens around 1 or 2%) then plug it into the charger and let it charge completely to 100%. Note that the LED will turn green at 90% .. so its not done yet!
Just my 2 coppers...
Sent from my T-Mobile G2 using xda premium
You are just calibrating the battery meter on the phone, not the battery. People constantly abuse the terminology.
You don't need to drain the battery to zero, because the battery meter is not even remotely that accurate in the best of circumstances. Draining to 10 or even 20% is no different than draining to zero.
What CAN happen if you drain to zero, is you you may trip the safety circuit on the battery, and render the battery unable to take a charge, thereby rendering it useless. Its not very likely, and safeguards on the phone are designed to prevent this, but plenty of people on here have had it happen. Full power cycles (draining to zero) also shortens the long term life of the battery. Especially considering there is NO value added to draining the battery to zero, there is no point it doing so intentionally, and taking an unnecessary risk.
Just charge your battery to 100%, let it sit on the charger for a while after full, to make sure its really topped off. Then use the phone until 10-20%. Repeat this a couple times. You can also go into recovery and clear battery stats before you charge/discharge. But I haven't noticed this to make much of a difference.
redpoint73 said:
What CAN happen if you drain to zero, is you you may trip the safety circuit on the battery, and render the battery unable to take a charge, thereby rendering it useless. Its not very likely, and safeguards on the phone are designed to prevent this, but plenty of people on here have had it happen. Full power cycles (draining to zero) also shortens the long term life of the battery. Especially considering there is NO value added to draining the battery to zero, there is no point it doing so intentionally, and taking an unnecessary risk.
Click to expand...
Click to collapse
Wow. I didn't know that. Thanks!
Sent from my T-Mobile G2 using xda premium
Draining the battery to a literal 0% is almost impossible. Lithium ion batteries do not allow devices to utilize all the juice in a the battery. Once a device shuts off and tell you the battery is "dead", there's actually a bit more juice that is only used by the battery to prevent the battery's level from becoming too low.
Think of it like space partitions in hard drives. While you can use 100% of a single partition in a hard drive. There will still be space left over in the other partition.
Now what mugen means is to not allow the battery to reach the 0% of the ENTIRE battery. In order to make that happen you would have to discharge the battery until your device doesn't turn on and then NOT charge the battery for a very long period of time. I'm talking weeks and months of no charge whatsoever. Other than that, feel free to allow your phone to die and charge it back up. This in conjuction with deleting your battery stats file will speed up the calibration process.
Hope I helped out.
Sent from my HTC Vision using Tapatalk
UnSungHERO420 said:
Draining the battery to a literal 0% is almost impossible. Lithium ion batteries do not allow devices to utilize all the juice in a the battery. Once a device shuts off and tell you the battery is "dead", there's actually a bit more juice that is only used by the battery to prevent the battery's level from becoming too low.
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Click to collapse
What is supposed to happen with the failsafes on the device and what ACTUALLY happens unfortunately are not one and the same. There have been plenty of people here that have let their batteries drain to zero, and then the battery will no longer take a charge.
True, the battery is not actually zero voltage. But its low enough that the safety circuit on the battery will prevent it from accepting a charge. The phone is SUPPOSED to prevent the voltage from dipping that low, but it doesn't always work. So the only way to bring the battery back to life, is with a special battery meter with a "boost" function. Since the vast majority of us do not have access to such a thing, the battery is effectively dead, as buying one is likely cheaper and easier than getting access to such a battery meter.
As I've already mentioned, this is unlikely to happen. But its happened to at least a few people with our phone, and I've seen it happen to other XDA users with other devices. No point in playing probabilities, if it happens to you, it sucks and it doesn't matter how "almost impossible" its supposed to be. As I already discussed, the battery meters on phones are not even close to accurate enough to read single, or even 5% battery increments. So draining to zero is not any more beneficial than draining to 10%. No benefit in draining to zero, so why risk it?
I have learned the hard way that discharging lithium ion batteries below 20% is the fastest way to kill them early! (greatly shorten their life)
thanks 4 replies, a lot of useful knowledge

Battery Calibration

I have seen a few threads about calibrating the battery, and I downloaded an app on the market, but I don't want to run it yet until i get some questions answered.
Is there a way that is better than others? Does calibrating the battery help with battery life, or what is the purpose?
stevew84 said:
I have seen a few threads about calibrating the battery, and I downloaded an app on the market, but I don't want to run it yet until i get some questions answered.
Is there a way that is better than others? Does calibrating the battery help with battery life, or what is the purpose?
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Click to collapse
Battery calibration does nothing. A google employee even confirmed that battery stats are only used for keeping track of what is using your battery (which it does not do very well IMO). So deleting them and discharging the battery then rebooting and all that other crap only wastes time.
As for fully draining and recharging the battery to calibrate it... in short it does much more harm than good. Older Ni-Cad batteries used to have a 'memory' of sorts. if you did not fully discharge them from time to time they would act dead when they wernt.
The batteries in our phones (and most newer electronics) are Lithium-Ion (and in some newer phones Lithium-Polymer). these batteries have no 'memory'. in fact discharging them all the way is very bad for them, and can actually cause the battery to rupture if its done too extreme (you would have to short the terminals for this to happen)
The reality of this is that the less you let your battery discharge, the longer it will last. Every time you let it drain all the way (or almost all the way) you are harming it and reducing its lifetime.
The best way to take care of your phone's battery is to try to keep it between 50% and 80% full. Even keeping the battery fully charged for very long periods of time can be just as bad as discharging it fully.
TL;DR: get rid of that app, and dont ever think about doing any battery calibration ever again.
Further Reading Here and Here
Klathmon said:
Battery calibration does nothing. A google employee even confirmed that battery stats are only used for keeping track of what is using your battery (which it does not do very well IMO). So deleting them and discharging the battery then rebooting and all that other crap only wastes time.
As for fully draining and recharging the battery to calibrate it... in short it does much more harm than good. Older Ni-Cad batteries used to have a 'memory' of sorts. if you did not fully discharge them from time to time they would act dead when they wernt.
The batteries in our phones (and most newer electronics) are Lithium-Ion (and in some newer phones Lithium-Polymer). these batteries have no 'memory'. in fact discharging them all the way is very bad for them, and can actually cause the battery to rupture if its done too extreme (you would have to short the terminals for this to happen)
The reality of this is that the less you let your battery discharge, the longer it will last. Every time you let it drain all the way (or almost all the way) you are harming it and reducing its lifetime.
The best way to take care of your phone's battery is to try to keep it between 50% and 80% full. Even keeping the battery fully charged for very long periods of time can be just as bad as discharging it fully.
TL;DR: get rid of that app, and dont ever think about doing any battery calibration ever again.
Further Reading Here and Here
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Click to collapse
Cool man, thanks...I'll skip on the calibration.

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