Database Info

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
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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.
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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.
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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.
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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?
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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.
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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] just got my new g2x how should i charge the battery?

my last g2x battery lasted like 4 hrs on a full charge what is the best way to charge the new one? do i let the battery run out then charge it?

When you first get a phone, you should let the battery die before charing it. Then charge it completely after it dies, this will maximize your battery life. If you charge it right out the box, you're actually reducing the amount of juice the battery can hold.

rashad1 said:
When you first get a phone, you should let the battery die before charing it. Then charge it completely after it dies, this will maximize your battery life. If you charge it right out the box, you're actually reducing the amount of juice the battery can hold.
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That's not really accurate. Lithium Ion batteries have no memory effect like older batteries so charging them from halfway full does not reduce the maximum capacity.
What happens is the phone needs to learn to measure the amount of mAh from the phone and recognize what battery % that means. By taking the phone through the full discharging and charging cycle, the battery drivers pick up on this and will better report the battery level. With a poorly calibrated battery, you do not get less battery, but instead you just will not see accurate information about the charge level. For example, my first discharge went quickly to about 10%, and even quickly below 5%, but stayed on for hours between 5% to eventually shutting off.
The battery still will not die faster, but my phone thought it was much lower than it was, giving it the appearance of dying faster. Point is, you can do the charge/discharge cycle whenever, not just the first time, and it won't effect your long term battery health.

1) do factory reset
2) drain completely
3) charge completely

thanks!
thanks everyone for your advice!

I think it really depends on who you ask. lol Some people will say let it drain first then charge it fully. I have read info on battery maker sites that suggest when you get their battery that you let it charge fully for at least 8 hours, then let it discharge fully. They say to do this the first 5 charges to increase battery life.
When I get a new phone or battery that's what I do. as soon as I get it I charge it up overnight, then let it discharge completely for the first 5 charges. I can only speak by my experience and my experience tells me it makes a difference. Here is my reasoning: me and my ex gf went one day to get new phones. We got the same phone. She started using hers as soon as we left the store. I waited. I charged it up overnight fully and did the conditioning procedure. Our phones were pretty much mirrors of each other app and software wise. Her battery would die out a couple of hours before mine. Battery usage also didnt report any HUGE differences in consumption .
Also every once and a while I go into Clockwork recovery and wipe battery stats(after it's been fully discharged) and re do the conditioning process. It might just be a mental thing, but for me this seems to work

supposedly from htc.....
1) Turn your device ON and Charge the device for 8 hours or more 2) Unplug the device and Turn the phone OFF and charge for 1 hour 3) Unplug the device Turn ON wait 2 minutes and Turn OFF and charge for another hour Your battery life should almost double, we have tested this on our devices and other agents have seen a major difference as well

I heard/read somewhere that you should never let a lithium ion battery fully discharge. It supposedly shortens its lifespan every time you fully discharge it. Instead, you are suppose to just top it off and not let it remain on the charger, for extended periods of time, once its reached a full charge. YMMV

*Omnipresent* said:
I heard/read somewhere that you should never let a lithium ion battery fully discharge. It supposedly shortens its lifespan every time you fully discharge it. Instead, you are suppose to just top it off and not let it remain on the charger, for extended periods of time, once its reached a full charge. YMMV
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Click to collapse
This is "more" true for everyday normal usage. Yes, you shouldn't constantly fully charge and fully discharge every time you use your phone. But for battery calibration it is necessary/beneficial.

I also hard that during the first charge after turning the phone off you have to strange on your head for ten minutes, then only use your left hand for the rest of the day and you will double your battery life

rashad1 said:
When you first get a phone, you should let the battery die before charing it. Then charge it completely after it dies, this will maximize your battery life. If you charge it right out the box, you're actually reducing the amount of juice the battery can hold.
Click to expand...
Click to collapse
Well I did it this way too. I get good batt
Sent from my LG-P999 using XDA Premium App

[Q] leaving the Transformer connected to the charger good or bad?

Hello everyone
I was wondering if its ok to leave the transformer connected to the charger.
Is it like the Evo with trickle down when it reaches 100%
I dont want to over charge it. If it were my laptop i would disconnect the battery at full charge. But its not possible to do that with the transformer.
I want to keep my cycle count low and prevent over charing.
I also wonder what happens in a few years when the battery is shot...

Charging is what damages Li-Ion batteries... I'd recommend not keeping it on the charger all the time. Android will purposely not keep the battery at 100% to help avoid some damage.
Li-ion prefer to be around 20-80% charge.

When battery is 100% and you keep the charger connected, heat will begin to build up and eventually you will kill your battery.
I'd do as with a notebook: charge till 100%, then remove battery or charger (in case of the tablet charger ) . Then use your tablet and recharge when needed / desired. And from time to time a full charge / discharge cycle won't do any harm.
Just my 2 cents.
Regards.

These tablets don't automatically recognize when it's fully charged and turn off the charging?

Ravynmagi said:
These tablets don't automatically recognize when it's fully charged and turn off the charging?
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Click to collapse
They do. There are other threads asking why thier TF's don't show 100% when unplgged from the charger. Same as it does on my Evo.

I think pretty much every modern device recognizes a full charge and responds accordingly. In fact, MacBooks will throttle performance if the battery ISN'T kept in while the system is running on A/C.
Heat will damage a battery, but it's not heat from charging but heat from operation. If a notebook is poorly designed and the battery is near a heat source, then removing the battery might be a good idea (except with the aforementioned MacBooks), but that's independent of the charging issue.
I think it's fine to keep it plugged in. These devices are smart enough to manage such things. Of course, the TF's charging cable's so short it's hard to use when plugged in, but that's a different issue entirely.

CalvinH said:
When battery is 100% and you keep the charger connected, heat will begin to build up and eventually you will kill your battery.
I'd do as with a notebook: charge till 100%, then remove battery or charger (in case of the tablet charger ) . Then use your tablet and recharge when needed / desired. And from time to time a full charge / discharge cycle won't do any harm.
Just my 2 cents.
Regards.
Click to expand...
Click to collapse
From what I understand this process cannot and will not kill the battery. This did happen in the old type of batteries with the ,emory effect but these new batteries and the OS's management system for charging does not allow the battery to be killed.
it will heat up and that would happen as there is a flow of electricity but not to a level that would kill the battery.
Cheers

IS it normal to go from 4% battery to 99% in under 3 hours ?
I thought this was supposed to take 8 hours to charge.
Cheers,
gpearson1968

gpearson1968 said:
IS it normal to go from 4% battery to 99% in under 3 hours ?
I thought this was supposed to take 8 hours to charge.
Cheers,
gpearson1968
Click to expand...
Click to collapse
Yes that's normal. It's meant to take about 3hrs.

Thanks guys...
Still dont know about it. Because I think its like my EVO and technology got so good that my battery is protected.
I really dont want my transformer to become a expensive paper weight or non-mobile because after a few years it has 45 mins battery life.

I've got the first full charge and full depletion done. Is it ok to use while charging now as long as I fully charge and fully deplete it a couple more times?

error12 said:
Thanks guys...
Still dont know about it. Because I think its like my EVO and technology got so good that my battery is protected.
I really dont want my transformer to become a expensive paper weight or non-mobile because after a few years it has 45 mins battery life.
Click to expand...
Click to collapse
batteries will degrade over time....would you be keeping this tablet for over 2-3 years? a simple battery change could work if ever needed

I am no expert, but I have spent some time searching around the internet looking for information on the best methods for improving the life of a battery. Most of the information I have found said it is bad to completely discharge a Li-polymer battery. The articarles stated it was best to charge the battery when it reaches 20% to avoid shortening its life.
Sent from my DROIDX using XDA App

Batteries are like muscles - they like to be exercised.
Leaving the unit plugged in WILL NOT HURT YOUR BATTERY. Period. The charging circuitry in modern devices is smart enough to cut current to the battery once it has reached a certain level of resistance.
Batteries do not like being deeply discharged. Most devices will shut off before the battery gets too deeply discharged, but it's never a good idea to tempt fate by running it until the device shuts off.
What really determines a battery's life is the number of cycles it has been put through. A cycle would be a full charge followed by a full (or to a lower end threshold) discharge.
The old original Lithium Ion batteries used in laptops would usually last about 300 full cycles or so - about a year if you used it on the battery every day. Partial discharges of course only count as fractions of a cycle.
Given the life of these types of devices, considering we'll likely upgrade to the next big thing in a year or so, I don't think anyone here will come close to 'wearing out' a battery.

EMINENT1 said:
I've got the first full charge and full depletion done. Is it ok to use while charging now as long as I fully charge and fully deplete it a couple more times?
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Click to collapse
As stated, these are Li-Ion batteries, and they do not need to be trained. The only reason you might need to do any training is to calibrate Android's understanding of the battery (although I doubt you need to do a full discharge for that, either).
It's not going to suddenly kill it, but it will over time hurt your battery's life.

I went ahead and did a full discharge/charge cycle, but only because Asus said to do so in the manual. Maybe the copywriter just copied/pasted from a circa 1990's manual for a device with a NiCd battery, but I figured if they're suggesting it, I might as well do it.

New device, how to deal with charge

Hi there, I own a Nexus 5 recently. The phone arrives soon and by everyone is know that battery comes with some charge. Should I leave discharge the battery complete and then charge back or how is this procedure in order to not kill the battery and gain a good calibration?
I have an extra question, is there any problem for battery if I leave the USB cable connected all the time even if battery is full?
Sent from my Galaxy Nexus using Tapatalk

Just charge it, don't fully discharge it and use it normally. You don't need to worry about calibrating

jd1639 said:
Just charge it, don't fully discharge it and use it normally. You don't need to worry about calibrating
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Click to collapse
You can use as normal..I normally drain it.
And in general, when dealing with lithium ion batteries, leaving them plugged in excessively when fully charged kills the battery in the long run

teh roxxorz said:
You can use as normal..I normally drain it.
And in general, when dealing with lithium ion batteries, leaving them plugged in excessively when fully charged kills the battery in the long run
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Click to collapse
Bad form on both counts. Li-ON batteries shouldn't be deep discharged. They have built in circuitry to prevent ACTUAL 0% (they shut down before getting to real 0%) but still not good to run it down to 5% all the time.
Unless you have some crappy charger & phone, the IC in the phone will instruct the charger to kill power when it's full so leaving it plugged in all the time wont make a difference - this is for a phone.
This is not the same and not for the same reasons in laptops. Reason it's not so good is if your laptop has crappy cooling system or like some people need it on "Performance" all the time because they don't want their CPUs "slowing them down". As a result of the heat from the system now going into idle state, the battery lifespan degrades. This is where your "plugged in all the time" stance comes from but it's not valid with all applications.

shotta35 said:
Bad form on both counts. Li-ON batteries shouldn't be deep discharged. They have built in circuitry to prevent ACTUAL 0% (they shut down before getting to real 0%) but still not good to run it down to 5% all the time.
Unless you have some crappy charger & phone, the IC in the phone will instruct the charger to kill power when it's full so leaving it plugged in all the time wont make a difference - this is for a phone.
This is not the same and not for the same reasons in laptops. Reason it's not so good is if your laptop has crappy cooling system or like some people need it on "Performance" all the time because they don't want their CPUs "slowing them down". As a result of the heat from the system now going into idle state, the battery lifespan degrades. This is where your "plugged in all the time" stance comes from but it's not valid with all applications.
Click to expand...
Click to collapse
Well very true, and I have an electronics background, so I know what works and what's alright. Discharging it is fine.

Thanks to all of yours I'll learn something new and now I know how to handle battery lifetime for best
Sent from my Galaxy Nexus using Tapatalk

Actually Shotta35 is 100% correct with regards to deep discharges and li-ion batteries. There is a write up I did in 2012 about battery care from a hardware prospective in my sig, and it has nothing to do with battery memory. teh roxxorz is also right about leaving batteries plugged in for extended periods of time. More energy = more heat = shorter lifesan.

Charging Battery

What's the consensus on when to charge and how long?
Is it safe to charge the S7 battery overnight, even if only around 50%? Or is it better to wait until your almost dead?
One of the I.T. guys at work was saying you should wait until you're below 20%, then always charge to 100%.

Just charge it whenever you want, this isn't the 90's or 2010. You'll probably replace your phone before you start to see it majorly affecting your battery.

You'll get a very slight improvement in overall battery life if you keep the charge between 25% and 75%. But we're talking very small. But yes, it's perfectly safe to charge your phone over night. The battery / phone / charger electronics won't overcharge the battery.
What you do want to avoid is draining the battery down to zero, or close to it. If at all possible, don't let the charge drop below 20 - 25% on a regular basis.

meyerweb said:
You'll get a very slight improvement in overall battery life if you keep the charge between 25% and 75%. But we're talking very small. But yes, it's perfectly safe to charge your phone over night. The battery / phone / charger electronics won't overcharge the battery.
What you do want to avoid is draining the battery down to zero, or close to it. If at all possible, don't let the charge drop below 20 - 25% on a regular basis.
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Click to collapse
Thanks for the info. I thought it was beneficial to charge all the way to full?
Sent from my SM-G930V using XDA-Developers mobile app

Lithium Ion batteries are different than older technologies, such as NiCad and NiMH. These batteries suffered from the "memory effect" (although not as badly as most people thought), so it was good to charge those fully. If you always charged them to, say 80%, they would eventually only take an 80% charge. Li batteries don't suffer from a memory effect, so you don't need to worry about that.
The other thing is that Li batteries hate three things: excessive heat, being fully drained, and being overcharged. Tesla stops charging when the battery pack reaches 75% of full charge, and displays that as a full charge. Similarly, they consider a 25% charge as "empty." Then again, a Tesla battery pack costs something like 10,000 bucks, so it's important to as much as possible to maximize the life of the pack.