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I always keep my pda in the cradle charging whenever I can (most of an average day) just like the instructions say so. A guy I work with says it's better for battery life to discharge them (near) fully and then recharge.
My battery life is now very short (after about 10 months use) and I am going to buy a replacement. Anyone know for sure which is the best way to keep batteries in good shape?
Thanks in advance ... Dr Firstpost
http://www.batteryuniversity.com/parttwo-34.htm
How to prolong lithium-based batteries
Battery research is focusing heavily on lithium chemistries, so much so that one could presume that all portable devices will be powered with lithium-ion batteries in the future. In many ways, lithium-ion is superior to nickel and lead-based chemistries and the applications for lithium-ion batteries are growing as a result.
Lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.
A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.
Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate. (Read more in 'Choosing the right battery for portable computing', Part Two.)
Aging of lithium-ion is an issue that is often ignored. Depending on the state-of-charge and storage temperature, lithium-based batteries have a typical lifetime of 2-3 years (longer if partially charged and kept cool). The clock starts ticking as soon as the battery comes off the manufacturing line. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance will reach a point where the pack can no longer deliver the stored energy, although the battery may still contain ample charge. Increasing internal resistance is common to cobalt-based lithium-ion, a chemistry that is found in laptops and cell phones. The lower energy dense manganese-based lithium-ion, also known as spinel, maintains the internal resistance through its life but loses capacity due to chemical decompositions.
The speed by which lithium-ion ages is governed by temperature and state-of-charge. Figure 1 illustrates the capacity loss as a function of these two parameters.
Figure 1: Permanent capacity loss of lithium-ion as a function of temperature and charge level.
High charge levels and elevated temperatures hasten permanent capacity loss. Improvements in chemistry have increased the storage performance of lithium-ion batteries.
There are no remedies to restore lithium-ion once worn out. A momentary improvement in performance is noticeable when heating up the battery. This lowers the internal resistance but the condition reverts back to its former state when the temperature drops.
If possible, store the battery in a cool place at about a 40% state-of-charge. Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. The most harmful combination is full charge at high temperature. This is the case when placing a cell phone or spare battery in a hot car. Running a laptop computer on the mains has a similar temperature problem. While the battery is kept fully charged, the inside temperature during operation rises to 45°C (113°F).
Removing the battery from the laptop when running on fixed power protects the battery from heat but some battery and laptop manufacturers caution against it. They say that dust and moisture accumulating inside the battery casing could damage the laptop. The dealers will be happy to provide you with a new pack when a replacement is needed a little sooner.
The question is often asked, should the laptop be disconnected from the main when not in use? With lithium-ion it does not matter. Once the battery is fully charged, no further charge is applied. It is recommended, however, to turn the laptop off overnight because heat harms the battery.
A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed batteries are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.
Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead. A charge with the original charger is no longer possible. Some battery analyzers (Cadex) feature a boost function that reactivates the protection circuit of a failed battery and enables a recharge. However, if the cell voltage has fallen below 1.5V/cell and has remained in that state for a few days, a recharge should be avoided because of safety concerns. To prevent failure, never store the battery fully discharged. Apply some charge before storage, and then charge fully before use.
All personal computers (and some other electronic devices) contain a battery for memory back up. This battery is commonly a small non-rechargeable lithium cell, which provides a small current when the device is turned off. The PC uses the battery to retain certain information when the power is off. These are the BIOS settings, current date and time, as well as resource assignment for Plug and Play systems. Storage does shorten the service life of the backup battery to a few years. Some say 1-2 years. By keeping the computer connected to the main, albeit turned off, a battery on the PC motherboards should be good for 5-7 years. A PC should give the advanced warning when battery gets low. A dead back-up battery will wipe out the volatile memory and erase certain settings. After battery is replaced, the PC should again be operational.
Simple Guidelines
Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.
Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.
Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing date. Do not buy old stock, even if sold at clearance prices.
If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.
_________________________
Created: February 2003, Last edited: June 2005
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About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc
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V
The short answer.
No. Lithium batteries prefer to be topped up frequently and don't like being fully discharged.
Thanks TheBrit :wink:
Just to add - you can do damage to a lithium battery by entirely discharging it, so don't. Top up away. But expect to replace after a couple of years!
V
Thanks for the replys & detail.
Maybe my batteries are suffering from 'digital memory' - they have hardly ever been run down to device switch-off. For my new ones I'll try fully discharging every 30 recharges as suggested and see how that goes.
I'll post results of test in a years time!
I don't believe in topping them constantly. A friend and I bought our new phones 2 weeks apart from each other. I always heard to discharge them before charging, he on the other hand never cared. Just 6 months in now, his dies in 2 hours or less, with light use. I am playing music, surfing FB etc. all day long. Right now at 15 hours discharging and still 40% battery. He has charged his 5 times today due to phone going into low battery life, and only been up 11 hours.
It only happens with the Niquel-Cadmium not with the Lithium
jrodcamaro said:
I don't believe in topping them constantly. A friend and I bought our new phones 2 weeks apart from each other. I always heard to discharge them before charging, he on the other hand never cared. Just 6 months in now, his dies in 2 hours or less, with light use. I am playing music, surfing FB etc. all day long. Right now at 15 hours discharging and still 40% battery. He has charged his 5 times today due to phone going into low battery life, and only been up 11 hours.
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Wut
Firstly.... go here and read this -
http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
The battery is fully charged when it is at 4.2 Volts and fully discharged at some predefined voltage (Lets say 3 volts).
The phone can measure these voltages directly from the battery. To see the voltage of your battery type *#*#4636#*#* into your phone and go to battery information.
If all that is so then what is the point or need of "recalibrating" and deleting battery stats and all that.
It seems logical to me that battery stats is just the place where your battery usage history is stored and nothing else.
Can someone confirm this or convince me otherwise?
(I rotate between 3 batteries and cannot grasp the idea that my phone can't consistently measure the charge level of the battery and operate accordingly.)
Measuring the Voltage to get the charge level is not very accurate, and has to be done with no load on the battery (that is, when its not in your phone).
So the phone has to count "energy used from"/"energy stored in" the battery for an accurate display. (called "Coloumb counter")
Did some test
I did a test on new a battery a while ago. Measure voltage when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The voltage showed on the phone using SystemPanel app is quite accurate with 0.04V margin of error. Most smart electronic measure lithium battery capacity according to the remaining voltage. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
Yet again how is this android development.
Sent from my GT-I9000 using XDA App
xufos said:
I did a test on new a battery a while ago. Measure current when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The current showed on the phone using SystemPanel app is quite accurate with 0.04V error margin. Most smart electronic measure lithium battery capacity according to the remaining current. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
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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...
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Sorry a typo and no caps deserve heavy flaming
bilboa1 said:
Sorry a typo and no caps deserve heavy flaming
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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?
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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
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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
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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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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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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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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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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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?
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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.
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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Click to collapse
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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Click to collapse
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.
As we all know, batteries, overtime tend to lose their capacity to hold charge, due to loss of free ions. Something, which we, the smartphone users are constantly worried about. I mean,nobody would like to let degrade a factory provided product.
So here, I am presenting a thorough analysis, which might help to slow down their deterioration.
Readers note, that the processes analysed below , are evidential for both the type of batteries, powering the current generation smartphones i.e LI-PO/LI-ION
INTRODUCTION-
Just as with other lithium-ion cells, LiPos work on the principle of intercalation and de-intercalation of lithium ions from a positive electrode material and a negative electrode material, with the liquid electrolyte providing a conductive medium. Thus,the more frequent are the charging times, more will be the ionic flow, further improving the withstanding capability of the electrolyte. Li-Ion and Li-Polymer batteries, if charged often, after about 1 month, would reach to their maximum performance, and by performance, I mean, the maximum capacity of charge it can hold. This doesn't have any noticeable effect on the battery life and so you are recommended to charge them every time you find an outlet.
EFFECTS OF COMPLETE/PARTIAL CHARGING -
Complete and partial charging, has their positive effects on battery's performance and life respectively, whilst harmful, vice-versa. Personal preference, here.
[COMPLETE]Improving the battery performance
For this section, performance should be prior to life cycle. This can be attained by allowing the battery to charge to their maximum potential permitted by its voltage rating. Adding full saturation of the permissible voltage boosts the capacity by about 10 percent but adds stress due to high voltage gradually affecting the battery life in the process.
OR
[PARTIAL]Maintaining the battery life.
For this section, life of the battery is everything for the user. The small boost may not feel significant, when you are sacrificing its lasting time. So they need not be fully charged, as is the case with lead acid, nor are desirable to do so. In fact, it is better not to fully charge, because a high voltage stresses the battery, as evident from above case. Choosing a lower voltage output, or limiting the saturation voltage altogether, effectively prolongs the battery life.
CHARGING WITH A HIGHER POWER OUTPUT
This misconception is popular in today's power users, charging with a output of a greater ampere rating, speeds up the charging. Yes, of course it does but distorting the final phase of charging in the process. Increasing the charge current does hasten or appears to hasten the charging process. But, though the battery reaches the voltage peak quicker, the saturation charge will take longer accordingly. The amount of charge current applied alters the time required for each stage; Stage 1 will be shorter but the saturation Stage 2 will take longer. A high current charge will quickly fills the battery to about 70 percent which is the initial phase. And reaching the peak voltage quickly, yet again pressurize the battery,reducing its life. However, choosing a lower voltage output, or limiting the saturation voltage altogether, adds up to the battery life.
MYTHS
The first time charging and "wait-until-full-discharge-before-recharge" and "don't-use-when-charging" are not applicable to these modern batteries. Waiting for complete discharge of a li-ion or li-po battery, totally stops the ionic conduction. And which might take a while to reactivate for their next conduction. Charging from scratch is recommended..
OTHERS-
Also follow the instructions about the batery temperature range.
Avoid keeping battery completely discharged for long periods of time.
Hope the article helps you all, get the most of your battery.
techy97 said:
As we all know, batteries, overtime tend to lose their capacity to hold charge, due to loss of free ions. Something, which we, the smartphone users are constantly worried about. I mean,nobody would like to let degrade a factory provided product.
So here, I am presenting a thorough analysis, which might help to slow down their deterioration.
Readers note, that the processes analysed below , are evidential for both the type of batteries, powering the current generation smartphones i.e LI-PO/LI-ION
INTRODUCTION-
Just as with other lithium-ion cells, LiPos work on the principle of intercalation and de-intercalation of lithium ions from a positive electrode material and a negative electrode material, with the liquid electrolyte providing a conductive medium. Thus,the more frequent are the charging times, more will be the ionic flow, further improving the withstanding capability of the electrolyte. Li-Ion and Li-Polymer batteries, if charged often, after about 1 month, would reach to their maximum performance, and by performance, I mean, the maximum capacity of charge it can hold. This doesn't have any noticeable effect on the battery life and so you are recommended to charge them every time you find an outlet.
EFFECTS OF COMPLETE/PARTIAL CHARGING -
Now this is a personal choice. You can choose either to-
1)Improve the performance of the battery (or)
For this section, performance should be prior to life cycle. This can be attained by allowing the battery to charge to their maximum potential permitted by its voltage rating. Adding full saturation of the permissible voltage boosts the capacity by about 10 percent but adds stress due to high voltage gradually affecting the battery life in the process.
2)Maintain the battery life.
For this section, life of the battery is everything for the user. The small boost may not feel significant, when you are sacrificing its lasting time. So they need not be fully charged, as is the case with lead acid, nor are desirable to do so. In fact, it is better not to fully charge, because a high voltage stresses the battery, as evident from above case. Choosing a lower voltage output, or limiting the saturation voltage altogether, effectively prolongs the battery life.
CHARGING WITH A HIGHER POWER OUTPUT
This misconception is popular in today's power users, charging with a output of a greater ampere rating, speeds up the charging. Yes, of course it does but distorting the final phase of charging in the process. Increasing the charge current does hasten or appears to hasten the charging process. But, though the battery reaches the voltage peak quicker, the saturation charge will take longer accordingly. The amount of charge current applied alters the time required for each stage; Stage 1 will be shorter but the saturation Stage 2 will take longer. A high current charge will quickly fills the battery to about 70 percent which is the initial phase. And reaching the peak voltage quickly, yet again pressurize the battery,reducing its life. However, choosing a lower voltage output, or limiting the saturation voltage altogether, adds up to the battery life.
MYTHS
The first time charging and "wait-until-full-discharge-before-recharge" and "don't-use-when-charging" are not applicable to these modern batteries. Waiting for complete discharge of a li-ion or li-po battery, totally stops the ionic conduction. And which might take a while to reactivate for their next conduction. Charging from scratch is recommended.
OTHERS-
Also follow the instructions about the batery temperature range.
Avoid keeping battery completely discharged for long periods of time.
Hope the article helps you all, get the most of your battery.
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Click to collapse
Great Guidance Sir! It's Little bit scientific but over all good job!
Suggestion:-
Add More Things To the post like why we should not use power saver apps, cache cleaners! How can we save juice of our device without using any app. Etc.
HIT THANKS IF I HELPED YOU SOMEHOW!!
dark_optimistic said:
Great Guidance Sir! It's Little bit scientific but over all good job!
Suggestion:-
Add More Things To the post like why we should not use power saver apps, cache cleaners! How can we save juice of our device without using any app. Etc.
HIT THANKS IF I HELPED YOU SOMEHOW!!
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That is a great suggestion, but based on my personal experience, the apps promising better battery life and others similar ones,were found to have no such noticeable effect,on either the battery's life or its performance,other than ram-eating hogs., which in turn actually, eats up the battery. I definitely wouldn't recommend any of those apps, for battery saving purposes, and neither do I use any of them.
techy97 said:
That is a great suggestion, but based on my personal experience, the apps promising better battery life and others similar ones,were found to have no such noticeable effect,on either the battery's life or its performance,other than ram-eating hogs., which in turn actually, eats up the battery. I definitely wouldn't recommend any of those apps, for battery saving purposes, and neither do I use any of them.
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Yap!