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.
Click to expand...
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
Related
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.
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.
Click to expand...
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
First off this isn't a guide about how to make your battery last longer between charges, at least it isn't yet. If a demand arises I will happily facilitate. *EDIT* For simplicity's sake I am including a link to V7's battery guide which addresses increasing the time between charges. ✭[GUIDE][26-07-2016]Extreme Battery Life Thread(Greenify+Amplify+Power Nap)✭This guide is about reducing wear that happens from many thing we all either knowingly do; out of a possible misunderstanding, or ignorance. All of this information is available doing a simple Google search, I am posting it here though for those who otherwise would not think to Google it. Furthermore I claim credit for absolutely none of this, but I do hope you find it helpful.
HOW TO PROLONG YOUR Li-Ion BATTERY'S LIFE
1) Keep your battery at room temperature: Heat is the worst enemy of your cell phones battery. So keeping your battery at room temperature (65-75*F) is the first step towards prolonging your battery's life. According to Battery University
each 8°C (15°F) rise in temperature cuts the life of a sealed lead acid battery in half.
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They also go on further adding
Once the battery is damaged by heat, the capacity cannot be restored.
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There are many things you can do to keep your battery cooler, such as taking it off the charger when the phone is done charging, and avoiding prolonged continuous usage. Also avoid leaving your phone in your car, it gets upwards of 140* in a car during the summer. The worst thing that can happen to a Li-Ion battery is a full charge and high heat, so avoid charging your phone until your car has cooled off if you are charging your battery in the car. Heat is by far the greatest factor when it comes to reducing the lifespan of a Li-Ion battery.
2) Use partial-discharge cycles: According to lancair.net
Using only 20% or 30% of the battery capacity before recharging will extend cycle life considerably
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Other sites I read while researching this stated that users should use up to 80% of their energy before recharging, they were all consistent with regards to a few things including: avoiding full discharges will prolong battery life, and it takes several partial charges to use one full charge cycle. Additionally Li-Ion batteries do not have "charge memory", but your digital device most likely does. Discharging the battery until cut off after every 30 charge cycles re calibrates the devices gauge.
3) Avoid keeping your battery at 100%: Every source I referenced for this guide said the same thing about keeping your battery at a full capacity, but oranageinks.com explains it most simply by stating
Permanent capacity loss is greatest at elevated temperatures with the battery voltage maintained at maximum (fully charged).
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4) If you are going to store your battery for an extended period store it at about 50% charged: This goes hand-in-hand with number 3. Also keeping the battery cool during extended storage will slow deterioration. Keeping the battery in a sealed bag or tupperware in your refrigerator is okay, but storing your battery in the freezer is not. When a battery is fully charged oxidation is occurring at its highest rate, and oxidation is essential corrosion. Oxidation occurs whether the battery is in use or not, for this reason it is better to get a high capacity battery rather than a spare. So with this said it almost should go without saying that if you can, buy batteries with a recent manufacture date.
5) Avoid completely discharging your battery: Lancair.com states:
Very deep discharges will quickly, permanently damage a Li-ion battery. Internal metal plating can occur causing a short circuit, making the battery unusable and unsafe. Most Li-ion batteries have protection circuitry within their battery packs that open the battery connection if the battery voltage is less than 2.5 V or exceeds 4.3 V, or if the battery current exceeds a predefined threshold level when charging or is charging
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If you found this helpful please don't forget to hit the "Thanks" button
now that explain why my battery drain so fast,my phone temperature is a bit high these days,thank you :good
I decrease my battry drain with installing som suitable kernal
this way realy effective in my device battry mangement
You're absolutely right, and you hit the nail on the head,
Saeedblack said:
realy[sic] effective in my device battry[sic] mangement
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But the physical battery itself needs care too. Device battery management is more related to how much power the CPU sees that the device has. Understanding how a Li-Ion battery works is kinda important at this point. So basically the positive electrode is made of Lithium cobalt oxide (cathode), or LiCoO2. The negative electrode is made of carbon (anode). When the battery is charging, ions of lithium move through the electrolyte from the positive electrode to the negative electrode and attach to the carbon. During discharge, the lithium ions move back to the LiCoO2 from the carbon. Over time the Lithium ions bond to the carbon thereby restricting the flow, creating resistance which decreases the battery's ability to deliver current. So properly caring for your battery is really the only thing that will slow the inevitable. Its kinda the same thing for a car...all cars eventually die, but if you take care of them they will last much longer than if you neglect them.
Thanks for this. It's not the usually same guide for battery improvementent.
My battery life got a little better.
Thanks mate, that's some good information.
Hi.
Just wondering:
in "5) Avoid completely discharging your battery"
Most battery calibration softwares say you SHOULD fully discharge your battery then fully charge it for a good calibration.
So, someone like me, who likes to try new roms, new nightlys all the time, are "slowly" burning the battery to ashes by calibrating it after every flash.
It looks like running the processor faster than specified (overclocking) can result in higher temperatures inside the device and faster battery wear as a result.
azraelus said:
Hi.
Just wondering:
in "5) Avoid completely discharging your battery"
Most battery calibration softwares say you SHOULD fully discharge your battery then fully charge it for a good calibration.
So, someone like me, who likes to try new roms, new nightlys all the time, are "slowly" burning the battery to ashes by calibrating it after every flash.
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YES you are slowly burning the battery out, by draining it after every flash. The battery is going to die inevitably anyways though, most of the sources I found suggest doing a "full drain" every 30 charge cycles. Perhaps this is when you should go ahead and do your battery calibration. Also a full drain is not exactly self-explanatory in this case. Your device may say that a battery has 1% of its energy left and to an extent it does, but the battery is designed to cut off before it gets too hot or too low. If you have a tendency to cut your phone back on after it dies then you will deplete the battery completely, possibly resulting in permanent damage.
adrian816 said:
It looks like running the processor faster than specified (overclocking) can result in higher temperatures inside the device and faster battery wear as a result.
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Yes O/C can raise temperatures of the device. Certain kernels run a little hotter than others. My device is currently O/C'd and isn't any hotter than normal when I am not using the device due to CPU governors and what not, and its only marginally hotter than it is when at the stock clock speed. Prolonged heavy use takes a toll on the battery, due to the heat its creating. Also don't let the little bit of heat increase stop you from O/C'ing your device. Many manufacturers use the same cpu with different clock speeds, EX Snapdragon S3 chip is used in the EVO 3D @ 1.2GHz, and the HTC Rezound @ 1.5GHZ from the factory. This is done to reduce power consumption on power hungry phones or to extend the life of a cpu that has proven itself reliable(such as in the example of the Snapdragon S3)...it also helps to market devices without spending more on development.
Good adwise! :good:
This is all very good advice. A lot of it I knew, but I learned a couple new things as well. Glad to see someone making it more easily available to our community!
Sent from my SGH-I777 using xda app-developers app
Found this same information when researching my netbook battery.Turns out there is a good reason it will sleep/hybernate/power off at 3 percent, can damage a cell. On the upside this one will charge faster.
Thanks for the information.
Sent from my GT-S5360 using Tapatalk 2
Oh god, by "avoiding keep it at 100%" you mean "don't use it constantly while charging", right?
I have a seriously problem.
Wish I could do something about #1. My phone can get pretty hot when I'm using it and I like to do a lot of things like playing games or dling torrents which gets it toasty.
Will definitely unplug before 100% from now on though. Thanks
Jane Shizuka said:
Oh god, by "avoiding keep it at 100%" you mean "don't use it constantly while charging", right?
I have a seriously problem.
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Yea that's pretty much the gist of it...heavy use while charging creates even more heat than just heavy use or just charging. Since doing the research for this thread I've been doing things a little differently myself. Instead of leaving it on the charger most of the day I charge it at night and use it til about 50% then charge it up to 80%...it may be in my head but I highly doubt it. Doing as I described I have had 1 full charge (from 40% to 100%) and a top off charge (50% to 80%) and my device has been on since yesterday morning (so 36 hours+ with only a 30% top off charge). This is with moderate use, and my phone is currently at 70%...MUCH better than before though.
This guide is still meant more for longer term physical battery care, but it appears to have helped extend time between charges.
zlc1 said:
Wish I could do something about #1. My phone can get pretty hot when I'm using it and I like to do a lot of things like playing games or dling torrents which gets it toasty.
Will definitely unplug before 100% from now on though. Thanks
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Try a different kernel, or underclocking your phone, that should help with the heat.
Thanks, I'll keep this in mind!
Thanks for the advice, but i thought discharge it completely wont do any harm to the battery since the protection circuit will stop at around 3..0-3.4 mV?
ryanshady said:
Thanks for the advice, but i thought discharge it completely wont do any harm to the battery since the protection circuit will stop at around 3..0-3.4 mV?
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That is about the point the device will cut off, but if you turn it back on like I used to until the device won't turn back on that's when the battery is completely discharged. Battery University goes on to say
Each cycle wears the battery down by a small amount. A partial discharge before charge is better than a full discharge. Apply a deliberate full discharge only to calibrate a smart battery and to prevent “memory” on a nickel-based pack.
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Link to article HERE
*EDIT*
i wish there's a way to stop charging once it reaches 85-95% like my laptop...
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
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that is true. the affect is probably minimal though(like we probably lose .7% of our battery per month if dont let it get low before charging it, instead of the typical 1% per month)
i get through half of my day with about 50% battery less, sometimes more. so i've made it a habit of charging it once i see it's around this 50% mark.
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
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The effect is accelerated/more pronounced below 20%...
Here is the good thing though... These phone's minimum operating voltage is higher than the minimum voltage of a Li ION battery. Using standard battery life measurements, the 0% according to the phone, is about 20% of standard.
Should you do a full discharge every now and then in order to calibrate the battery? I haven't been able to find a definitive answer on this in other related threads. Some say you should, some say it's not necessary since the battery doesn't have memory cells. I have never let my battery get below 50% and everything seems to work fine but it does seem to make sense to do a full discharge from time to time so the battery knows its capacity.
Jspeer said:
Should you do a full discharge every now and then in order to calibrate the battery? I haven't been able to find a definitive answer on this in other related threads. Some say you should, some say it's not necessary since the battery doesn't have memory cells. I have never let my battery get below 50% and everything seems to work fine but it does seem to make sense to do a full discharge from time to time so the battery knows its capacity.
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Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
I let mine get low all the time I use my phone a lot. Hopefully its not to expensive to replace battery since Google thinks that replacing a battery is to complicated for us tech savvy people
Justice for Kelly Thomas RIP
I don't worry about it. I charge it overnight. If I've over used it in the day and I feel it will die before bed, i'll top it up but not to protect the battery. Just to ensure I can use my phone.
If they wanted you to do anything special with charging / draining, it would be in the instructions
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markdapimp said:
Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
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The battery itself does not but occasionally the controller needs a kick in the pants. Deep drains on li-ion should be avoided at all costs. The phone hasn't been out long enough to even think about the sort of problem. But after a couple hundred charges you might see a behavior that will be corrected by one full discharge.
Its not uncommon to see cases where you actually replace the cell behind a controller and the controller not picking up the change in capacity. Never in cell phones mostly laptop battery rebuilds etc but it exhibits an idea of what happens. The battery controller takes note of the original, current maximum and current charge capacity. Not sure how I suppose voltage versus read amp hours. But as a battery gets old you might start seeing the maximum capacity reading fluctuate. But if at any time the actual chemical capacity is higher than the controller thinks it is the controller will prevent the battery from reaching its potential.
Used to have older PSP batteries reach 100% real quick, quick fix was to deep discharge through the controller using a small light bulb. The battery would then take a significant charge and last a few more months before kicking the bucket.
Jspeer said:
I read that a battery will last longer if you don't let it get below 40%, and full discharges are bad for the longevity. Is this true? Here is a good read on the subject. http://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
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40% is a good number for storage, its actually better to store it at 40% than 100%. Actual use 20 to 25% is my personal range but I would say just never let it get below 15%. Lithium Ion does not mind being topped off. Deep discharged will ruin it real quick. My laptop battery lasted 3 years never letting it go below 25%, murdered a cell phone battery once a year letting it die.
I let it go to 1% and turn itself off. Then I charge it back up. But if I know I am going out in the next few hours I charge it as much as I can before I leave.
markdapimp said:
Li-ON battery's do not need to be calibrated. that was only with old battery tech such as Ni-Cad or NIMH
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lots of the fuel gauges for these types of batteries do need to be calibrated. this is not true for the N5 though(i think). I want to say i remember reading that this fuel gauge is different, like a 'smart fuel gauge' or something
kmx said:
I let it go to 1% and turn itself off. Then I charge it back up. But if I know I am going out in the next few hours I charge it as much as I can before I leave.
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You shouldn't do that almost ever. And by no means as a regular practice.
Molitro said:
You shouldn't do that almost ever. And by no means as a regular practice.
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Thats what the built in protection is for:
Marine6680 said:
The effect is accelerated/more pronounced below 20%...
Here is the good thing though... These phone's minimum operating voltage is higher than the minimum voltage of a Li ION battery. Using standard battery life measurements, the 0% according to the phone, is about 20% of standard.
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Enddo said:
lots of the fuel gauges for these types of batteries do need to be calibrated. this is not true for the N5 though(i think). I want to say i remember reading that this fuel gauge is different, like a 'smart fuel gauge' or something
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Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
LI-ON battery's have a different chemistry which allows them to store greater capacity without loss like NI-CAD and NIMH did this is why you turn off your phone for a week and turn it on you find it still has about the same battery percentage as you turned it off before.
here's an example of a NI-CAD battery which needs to be calibrated.
You have a drill you haven't used for 3 days it was fully charged before you put it away if you take that same drill 3 days later you'd find it dead. where as LI-ON battery's would still be alive and full capacity. if you charge it from there it wouldn't be calibrated. as calibration requires you to drain the battery 2 times or more till it reaches it full capacity and charge it back up to 100% and repeat.
If you were to do that with a LI-ON battery you're basically doing nothing but wasting your charge cycles on the battery and you could kill it as LI-ON battery's DO NOT LIKE TO BE EMPTY
Because of all that NI-CAD and NIMH mess mostly all power tools you'd find in a shop such as home depot are now equipped with LI-ON battery's as they don't require calibration and can be left for months and it would still have its initial capacity prior to charging because Ni-cad battery's suffer from a memory effect and LI-ON does not, NI-CAD Requires full discharge before recharge LI-ON does not you get the point here right? LI-ON is better!
Now for those apps that claim calibrate the battery they do nothing they just Improve the reading of the software in android to get the battery percentage which is reset every time the battery charges to 100% so in short don't calibrate your battery
You can read more here http://www.diffen.com/difference/Li-ion_vs_NiCad
and watch this video: http://www.youtube.com/watch?v=hrcbcm11830
markdapimp said:
Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
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The battery controller is still the source of the problem. If the batteries chemical capacity at a given moment is 1800 mah down from its original 2300 and the charge controller thinks the capacity is 500 the controller will only charge the battery to 500. Most controllers do not act like their dumber counter parts which will trickle or cut off when the cells characteristics indicate it is reaching a full charge.
The controller in these batteries while varying greatly in design all have one thing in common. They are designed for safety. The controller will actually stop accepting a charge forever if the voltage of the cell goes below a certain point. It will also never charge it above the current observed maximum capacity no matter what reality is.
You can poll a battery using vendor specific commands to get the designed, current maximum and current charge. The current maximum charge capacity is a changing value it will change over the life of the battery. This was an aging laptop battery that while the controller knew what the "Full Charge Capacity" was currently it decided not to report that to windows resulting in a hilarious 410%.
But we are talking about a problem that really won't rear its head for 1 or 2 years and were talking about doing it once or twice over the life of the battery. People doing it now and all the time WILL kill the battery very quickly for no benefit.
markdapimp said:
Its not any different. as with older battery technologies they would loose capacity until they are calibrated 0% to 100% this is due to the chemistry of the battery
LI-ON battery's have a different chemistry which allows them to store greater capacity without loss like NI-CAD and NIMH did this is why you turn off your phone for a week and turn it on you find it still has about the same battery percentage as you turned it off before.
here's an example of a NI-CAD battery which needs to be calibrated.
You have a drill you haven't used for 3 days it was fully charged before you put it away if you take that same drill 3 days later you'd find it dead. where as LI-ON battery's would still be alive and full capacity. if you charge it from there it wouldn't be calibrated. as calibration requires you to drain the battery 2 times or more till it reaches it full capacity and charge it back up to 100% and repeat.
If you were to do that with a LI-ON battery you're basically doing nothing but wasting your charge cycles on the battery and you could kill it as LI-ON battery's DO NOT LIKE TO BE EMPTY
Because of all that NI-CAD and NIMH mess mostly all power tools you'd find in a shop such as home depot are now equipped with LI-ON battery's as they don't require calibration and can be left for months and it would still have its initial capacity prior to charging because Ni-cad battery's suffer from a memory effect and LI-ON does not, NI-CAD Requires full discharge before recharge LI-ON does not you get the point here right? LI-ON is better!
Now for those apps that claim calibrate the battery they do nothing they just Improve the reading of the software in android to get the battery percentage which is reset every time the battery charges to 100% so in short don't calibrate your battery
You can read more here http://www.diffen.com/difference/Li-ion_vs_NiCad
and watch this video: http://www.youtube.com/watch?v=hrcbcm11830
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look man
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles to prolong life, other than to calibrate the fuel gauge on a smart battery once in a while.
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now believe what you want
Once in a while isn't explicit. The video posted earlier says once a year or so... both of those are "a while" to me
It all depends on the controller and the software but mostly its no longer necessary.
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Molitro said:
You shouldn't do that almost ever. And by no means as a regular practice.
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Thanks for the recommendation.:angel:
rootSU said:
Thats what the built in protection is for:
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Fair enough.
But still doens't seem like a good practice given how the recommendations with this kind of tecnology are usually don't go too low and try to charge at different values, not always plug the charger at the same level.
Li Ion batteries charge to a maximum voltage before the charge stops in a phone or other device that charges while also operating.
To fully charge a Li Ion battery you need to monitor current draw of the battery as it is charging, it drops as the cell reaches saturation. This is difficult to do in an operating circuit... Though the tech may be getting better, as load sharing was not common for charging cell phones a few years ago, but it may now be, I have actually been looking for info on powered device charging, but find little beyond load sharing type.
So the battery in a phone could hold more juice if it was charged out of the device, and more still if the phones could run at the 3v minimum of Li Ion. (min voltage of arm devices is around 3.5v) Load sharing chargers can charge fully though.
Also charge rate affects battery life... slower charging is better for long lifespan. If you overnight charge, use the lowest rated charger you have, or standard USB charging. The current phones come with higher amp chargers now... It really doesn't speed up the overall charge cycle to 100% very much, but it does make charging to 80% quicker. So you can do a quick charge of a low battery to a usable level in a hurry.
Power tools use LiFe chemistry batteries which are more tolerant of abuse and misuse... at the cost of less voltage and capacity and more weight.
I work from home so it's easy for me to top off the phone as needed. I'll usually throw it on the charger for a while around 3-ish PM to make sure that I have a full charge going into the evening since I do a lot of reading on it after the kids are in bed. I'm definitely what you would call an opportunistic charger - there's no need to drain the battery all the way unless you absolutely can't get to a charger. I don't understand why people choose to run their batteries down all the way when they don't have to.
For some reason once my phone hits 8% battery life it drops to 2% immediately.
This happens on viperxl & cm, so its not ROM related.
Any ideas on how to fix it? Is there a way to recalibrate the battery ?
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There's nothing wrong with your battery. That's normal behaviour when the battery is at such a low level. The battery percentage is never an exact value, it's only an estimate based on the current voltage that is being reported by the battery. When a battery is that low it isn't abnormal at all for it to jump down drastically like that.
On a side note, unless you're performing an initial charge cycle after flashing a new ROM you really shouldn't let your battery deplete to such a low level. With this specify type of battery technology it's quite bad for it and will actually affect the long term life of the battery. The preferred method of charging is to do regular top up charges from anywhere between ~80% and ~30% battery level right up to the 100% mark.
Sent from my Evita
The_Zodiac said:
Any ideas on how to fix it? Is there a way to recalibrate the battery ?
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There is no such thing as "recalibrating the battery". This term is sometimes used by folks who confuse Li ion technology with old NiCad batteries that need to be "conditioned".
What you may mean is recalibrating the battery meter, which has to do with software, not battery chemistry. Battery meter is usually not accurate after a ROM flash, and should be recalibrated. This is done by charging to 100% (let it sit for half hour or so at full, to ensure any saturation charge is achieved) then deplete until around 10 or 20%.
Other than that, the meter is as accurate as its going to get. As timmaaa already stated, the battery % is just an inaccurate approximation of the amount of usage left that corresponds to various voltages. It often can't be trusted to be accurate to within 1% (or even 5%) increments. And also as timmaa stated, you should not be draining your battery that low on a frequent or habitual basis, as its harmful to the long term life of the battery. Charge frequently.