Related
Firstly.... go here and read this -
http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
The battery is fully charged when it is at 4.2 Volts and fully discharged at some predefined voltage (Lets say 3 volts).
The phone can measure these voltages directly from the battery. To see the voltage of your battery type *#*#4636#*#* into your phone and go to battery information.
If all that is so then what is the point or need of "recalibrating" and deleting battery stats and all that.
It seems logical to me that battery stats is just the place where your battery usage history is stored and nothing else.
Can someone confirm this or convince me otherwise?
(I rotate between 3 batteries and cannot grasp the idea that my phone can't consistently measure the charge level of the battery and operate accordingly.)
Measuring the Voltage to get the charge level is not very accurate, and has to be done with no load on the battery (that is, when its not in your phone).
So the phone has to count "energy used from"/"energy stored in" the battery for an accurate display. (called "Coloumb counter")
Did some test
I did a test on new a battery a while ago. Measure voltage when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The voltage showed on the phone using SystemPanel app is quite accurate with 0.04V margin of error. Most smart electronic measure lithium battery capacity according to the remaining voltage. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
Yet again how is this android development.
Sent from my GT-I9000 using XDA App
xufos said:
I did a test on new a battery a while ago. Measure current when the battery completely empty and fully charged.
Empty battery
1% remaining, using SystemPanel
Take the battery out and measure it with Multimeter
Fully charged
100% charged
Again, measure it with Multimeter
The current showed on the phone using SystemPanel app is quite accurate with 0.04V error margin. Most smart electronic measure lithium battery capacity according to the remaining current. In this case, fully charged SGS is 4.2V, empty is 3.5V.
Me too, don't know why we have to delete batterystats.bin to recalibrate battery indicator But I do know that SGS keep track on power consumption on each of its component/application. Its a little bit silly if SGS reads batterystats.bin and display it as battery indicator.
Click to expand...
Click to collapse
Thanks for that, but you were actually measuring the Voltage, not current (Amperes).
In any case, for laptop Li-ion batteries there is normally a capacity counter (Coulomb counter) that reports the capacity in terms of mAh (milli-ampere hours). It can normally report the remaining capacity, maximum capacity, design capacity, and can be used to measure the *actual* power drain (in terms of Watts).
I wonder if Android has APIs that let apps access that kind of information?
Not really sure about this, but:
Phone seems to measure both voltage & discharge speed, "predicting" remaining charge.
It happens that after a flash battery indicator jumps to a higher value (not compatible with the couple of minutes of dc connection it had), and fall to a way too low value after any battery intensive task (a few minutes of audio call are enough), once more not compatible with the real usage.
I should inspect android code to be shure of this, but I suspect batterystats.bin is used to keep track of battery usage and to this sort of prediction, while a firmware flash seems to mess somehow the measurement.
Edit: this is based on my direct experience, even if on just "empirical" tests. I'll take a look to code asap
'mkay, battery talk... always interesting to see what people make of this.
Let's help out all the misunderstandings here and start with the basics
First of all: read the basics on Li-ion batteries:
http://electronics.howstuffworks.com/lithium-ion-battery.htm
second:
you DON'T measure your voltage when your battery is disconnected. Because it will rise to the normal values of the battery after a while. When you connect it, and use it, the voltage will lower. Compare it to a garden hose. if you let water run out, the presure drops and water starts flowing (presure is voltage, flowing is the current). If you measure the presure when there is no water running, the presure will always mount to the default value, even if there is "not much water left in the tank". But when it starts running again, it could very well run out very fast. So in comparison: voltage says something, but only when you "use" it.
Third:
When a battery ages, it's characteristics change, it will be full... and then all at once, empty. It's not linear. So calculating the capacity is always a bit "guessing". (compare it to stones in your water tank... they don't give you water, the tank doesn't change, but all of a sudden, you're out of water).
conclusion:
capacity of a battery is a very tricky thing to do, it's a combination of voltage, current, age... so the best way to determine capacity is by using the history of the battery as the "guide" to the future. Resetting the battery statistics will remove that history and your phone will have to "learn" it's behavior again. If you don't reset your stats, your values will become more reliable over time (depending of course on the time the stats are kept )
For those who speak dutch, i put a complete battery description/howto/misunderstandings post on www.modelbouwforum.nl (search for posts of "harrydg")
If there are more questions or so, just ask, i'll try to help out as much as possible...
wow harrydg that's great explanation, wish you were my physics teacher back in high school
someone add this post to the main FAQ!
I just wanna write it in a simpler way:
You've access to the battery stats from the kernel. And of course its current consumption which is measured not voltage. Voltage doesn't tell all that much. During high draws your voltage (at the battery level) can fluctuate quite a bit.
There's a regulator (or probably a bunch of them) get a stable voltage no matter what the input voltage is (well, still it has to be in the 3.3/5v range probably else the regulator burns)
Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity.
Not only the battery capacity changes from battery to battery but it also changes during the life time of the battery.
The *only* way to calibrate the battery, is to delete the stats, have a fully charged phone and let it drain out the battery until it turns off. That way the kernel will measure for example 1457mah used until it ran out of juice, and that's your battery capacity then. Having the full capacity allows the kernel to give you a rather precise estimate of your current battery status (eg "80%" that you see on the top of the screen) (of course the actual calculation is a bit more complicate but that's the basics)
If calibration stats storage is changed for any reason (probably kernel upgrade or just a whacky samsung implementation that gets corrupted for some reason) you need to delete it and make a new one to recalibrate.
If you want to make it simpler, make it at least correct...
"Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity."
First of al, it's mAh, which means milli ampere hour, NOT per hour, that would be mA/h, which it is not.
mA is milli ampere, which is a current
there is a significant difference between the 2.
the first is "capacity"
the second is "current"
it's like a bottle. The capacity is 2l and you pour at 1l per minut...
so... make it simple please...
My guess is, that android is measuring the known min and max by the battery reported values, stores them and calculates the percentages.
So it is device and battery independent.
harrydg said:
If you want to make it simpler, make it at least correct...
"Anyway, that's also why the battery stats have to be calibrated, while you can measure how much current is used (in maH aka milli amp per hour, or in mA aka "instant" milli amps), you don't know the battery capacity."
First of al, it's mAh, which means milli ampere hour, NOT per hour, that would be mA/h, which it is not.
mA is milli ampere, which is a current
there is a significant difference between the 2.
the first is "capacity"
the second is "current"
it's like a bottle. The capacity is 2l and you pour at 1l per minut...
so... make it simple please...
Click to expand...
Click to collapse
Sorry a typo and no caps deserve heavy flaming
bilboa1 said:
Sorry a typo and no caps deserve heavy flaming
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Click to collapse
hehe, sorry for the rant, but if you want to put it simple, make sure the terminology and abbreviations are correct. If not, people will take over the mistakes and conversations will go totally wrong because of misunderstandings...
Thanks very much for the feedback guys. It makes more sense now.
It's using batterystats to get familiar with discharge rates in order to give an accurate estimation of remaining charge and a prediction of when it will run dry.
Can it misreprasent these values and forcibly power down the phone when there is still charge remaining?
And likewise can it stop the charging process prematurely, estimating the battery to be at 100% charge when it is lower?
Is this the reason to recalibrate?
Heres one thing what I noticed about the battery stats, some say deleting it fixes the guage and does not really recalibrate the battery, I really doubt there is a way for end users to do that, even if you never delete the battery stats bin and your drain is pretty fast, it significantly slows down when your battery hits around 25~35, the lower the power on the battery the more accurate it can be represented regardless of the calibration. This is applicaple for the SGS only.
Now it comes to the question..
If the phone create battery stats every time the phone reboot, then when is the best time to delete and the best way to calibrate?
This is what I normally do..
..delete stats at 5%, let it run dry til it turn itself off, dont turn on but connect the charger til it fully charged. Turn phone on and ill have fully charged battery along with fresh stats.
Is this correct?
vosszaa said:
Now it comes to the question..
If the phone create battery stats every time the phone reboot, then when is the best time to delete and the best way to calibrate?
This is what I normally do..
..delete stats at 5%, let it run dry til it turn itself off, dont turn on but connect the charger til it fully charged. Turn phone on and ill have fully charged battery along with fresh stats.
Is this correct?
Click to expand...
Click to collapse
On the SGS theres no real point in deleting it, unless you dont really wanna see the battery go down to 35% and stay there for a while, how ever busted your battery indicator is it gets very accurate as the lower it goes.
I never found batterystats made any difference. What did make a difference is the rom or kernel, what widgets, lagfix e.t.c
If you get more than 1% battery drain per 5hr standby then something is wrong
Sent from my GT-I9000 using XDA App
android53 said:
I never found batterystats made any difference. What did make a difference is the rom or kernel, what widgets, lagfix e.t.c
If you get more than 1% battery drain per 5hr standby then something is wrong
Sent from my GT-I9000 using XDA App
Click to expand...
Click to collapse
I find that conclusion quite flawed.
First of all, what's your definition of standby?
3g on? Wireless on? Autosync on? There are also noticeable differences between different firmwares and between 2.1 and 2.2.
In addition, most people are reporting somewhere around 1% per 1 hour standby or 1% per 2 hour standby, which it what I have been experiencing as well. Sometimes, apparently for no reason, it can drain faster than that, maybe 1% per 0,5 hour or more. I think this might be some widgets fault.
1%/5h standby 3g no sync
i get 1%/2h with data and sync
Depends on your reception, im just basically saying if your losing say 8% battery overnight or more then something is wrong unless your polling several push email accounts
My Droid 2 global's battery life is not good,nearly 1 day for each full charge(i used room fission 2.4.3)Is there any way to improve the battery life
If you're getting a whole day out of one charge that's outstanding battery life.
Sent from my Droid 2 Global running Fission Rom
Too sad to hear that exacly i used about 20 hours.How about you?i heard that if use CDMA the battery life will better?
I've heard something of the like, but nothing conclusively. I've heard that underclocking the cpu can help (if you want to root your phone). So can using a rom like Fission, which doesn't have the stock Blur that, although somewhat nice, is a big drain on batteries. This would naturally be a pretty big change though. You can also get the extended battery for <$50 which I heard helps a bunch.
adridge said:
I've heard something of the like, but nothing conclusively. I've heard that underclocking the cpu can help (if you want to root your phone). So can using a rom like Fission, which doesn't have the stock Blur that, although somewhat nice, is a big drain on batteries. This would naturally be a pretty big change though. You can also get the extended battery for <$50 which I heard helps a bunch.
Click to expand...
Click to collapse
Yep,underclocking the cpu and use room Fission make the battery maintain more longer(i'm using gsm not cdma).In my country (VietNam) someone sells Droid's battery for only 10$,i'm thinking to get one
Just got my D2G, I put it on CDMA only and the battery still sucks. It went from 80% to 40% overnight and it was set for night time battery save mode.
eaglewwit said:
Just got my D2G, I put it on CDMA only and the battery still sucks. It went from 80% to 40% overnight and it was set for night time battery save mode.
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Click to collapse
Wow that's strange, I left my phone overnight not charging because it hit 100% before I went to bed, and 10 hrs later it was still at 90%, sitting idle my phone uses nearly no power. However I never used the battery save mode and I only just recently put it in only CDMA mode just to see if that makes life any better.
I've found that the biggest drain on the battery is having mobile data switched on in an area where the phone can't keep a clear lock on 3G and is constantly switching between 1x and 3G.
After switching to Fission, underclocking, keeping gps and wifi off unless I'm using them, turning the brightness down to 10% except when outside in the sun, and managing apps that sync background data, I can use the phone pretty heavily and get a full day (15-18 hours) out of my battery. Considering I put it in the media dock for use as my alarm clock every night, that amount of battery life is perfectly fine.
BTW, I use SetCPU for underclocking. I set the max speed to 1GHz with On Demand scaling. I also have profiles to scale down the speed to 600MHz when the battery gets low or when the screen is off (which helps with the background data stuff). At 600MHz it's still faster than my original Droid, thanks to the doubling of memory in the D2G.
So far Today after 5 hours of moderate use I went from 100 At 50 on the battery. Is this normal?
Update:
Phone on for 7 hours and the battery is down to 30%, something must be wrong, right?
eaglewwit said:
So far Today after 5 hours of moderate use I went from 100 At 50 on the battery. Is this normal?
Update:
Phone on for 7 hours and the battery is down to 30%, something must be wrong, right?
Click to expand...
Click to collapse
Check what's been using the battery. That might help pinpoint what's going on.
eaglewwit said:
So far Today after 5 hours of moderate use I went from 100 At 50 on the battery. Is this normal?
Update:
Phone on for 7 hours and the battery is down to 30%, something must be wrong, right?
Click to expand...
Click to collapse
I wouldn't call it very unusual TBH
900 am to 900pm and battery down to 30% with moderate usage. I hope there is someway to improve this. My iphone during the same time period with about the same usage and at least an hour playing bejewled only droped to 70%
zse45tgb said:
BTW, I use SetCPU for underclocking. I set the max speed to 1GHz with On Demand scaling. I also have profiles to scale down the speed to 600MHz when the battery gets low or when the screen is off (which helps with the background data stuff). At 600MHz it's still faster than my original Droid, thanks to the doubling of memory in the D2G.
Click to expand...
Click to collapse
zse45tgb,
Does SetCPU only require root and SU?? BTW I used SetCPU on my Eris and it was a lifesaver.
Haven't gone the Fission route just yet but loved ROMs on my Eris, such a battery saver. Really hope the dev's can make it happen.
Don't mean to sound like a twit here, but I used to have a huge problem with the battery life... when I was dicking around with it for hours at a time. Try only using it when you need to. Don't sit on facebook/maps/using it for pointless things for extended periods of time. I have found that just using it moderately has had the most dramatic impact on battery life. I can maintain complete functionality of my phone when I need it, and still have at least 50% battery by midnight. If you are using it that heavily, then maybe you should carry a charger around with you? Hope this helps.
Idk how you guys get such terrible batt life. i have mine OVERclocked to 1.35 ghz. i also have profiles to lower that as the batt goes down. I have everything that updates set to update every 30 mins, which is quite frequent. i dont mess with screen brightness, i let it auto adjust. I play games on occasion (SNESoid), facebook frequently, alot of texting and my battery lasts 18-20 hours every day, consistently. When you first got the phone you let it charge for 8 hours right away right? if not...theres your problem, and your battery will probably self destruct in a few months...give or take a few months lol.
Use The Following Settings to Help Maxmize Your Battery Life
I've been using the following settings on the Fission 2.4.3 Rom and I've noticed my battery life has increased at least 6-8 hours longer. I was considering returning my D2G before, but now it is definitely manageable.
Installing the SIM Card HotFix using the Fission Rom Manager
Adjusting my mobile networks to "CDMA / EvDo auto" in "Settings" -> "Wireless Networks" -> "Mobile Networks" -> "Network Mode"
Underclocking my CPU to 1Ghz using SetCpu
If you really want to save some more power combine these settings with Juice Defender. I've noticed a bit of lag here and there while using it, but that's the trade off for longer battery life.
I can confirm zse45tgb post about losing a lot of battery in an areas with poor 3g reception. When I'm at work my battery will drop much faster then when I'm at home where my 3g reception is great.
Props to AngDroid and the rest of Team Defuse.
Hope this helps someone else out there begin to enjoy their D2G.
botnryan said:
Idk how you guys get such terrible batt life. i have mine OVERclocked to 1.35 ghz. i also have profiles to lower that as the batt goes down. I have everything that updates set to update every 30 mins, which is quite frequent. i dont mess with screen brightness, i let it auto adjust. I play games on occasion (SNESoid), facebook frequently, alot of texting and my battery lasts 18-20 hours every day, consistently. When you first got the phone you let it charge for 8 hours right away right? if not...theres your problem, and your battery will probably self destruct in a few months...give or take a few months lol.
Click to expand...
Click to collapse
these are li polymer batterys...not nicad. lol. so they dont need "warming" up the first time... the first charge is the same as the rest. it should be charged in around 90mins tops. a li-pol battery isnt able to accept a trickle charge (would damage it) so leaving it on past 100% is uneccessary and potentially damaging. i wouldnt recommend ever leaving your battery on for 8hrs. as soon as its charged unplug it. if you leave it connected then the charger will switch off, you will then be using the battery, the battery will eventually drop to 90% and then the charger will turn back on. youll be continuously topping the battery from 90 up to 100 and back again. a waste of electricity and im sure it wont do the battery or charger any good.
theres also no need to fully discharge the battery.
a quote from http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
"Preparing new lithium-ion for use
Unlike nickel and lead-based batteries, a new lithium-ion pack does not need cycling through charging and discharging. Priming will make little difference because the maximum capacity of lithium-ion is available right from the beginning. Neither does a full discharge improve the capacity of a faded pack. However, a full discharge/charge will reset the digital circuit of a 'smart' battery to improve the state-of-charge estimation"
ckfalls said:
zse45tgb,
Does SetCPU only require root and SU??
Click to expand...
Click to collapse
Yes, that's all. You can use it on the stock Moto rom.
anothadave said:
these are li polymer batterys...not nicad. lol. so they dont need "warming" up the first time... the first charge is the same as the rest. it should be charged in around 90mins tops. a li-pol battery isnt able to accept a trickle charge (would damage it) so leaving it on past 100% is uneccessary and potentially damaging. i wouldnt recommend ever leaving your battery on for 8hrs. as soon as its charged unplug it. if you leave it connected then the charger will switch off, you will then be using the battery, the battery will eventually drop to 90% and then the charger will turn back on. youll be continuously topping the battery from 90 up to 100 and back again. a waste of electricity and im sure it wont do the battery or charger any good.
theres also no need to fully discharge the battery.
a quote from http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
"Preparing new lithium-ion for use
Unlike nickel and lead-based batteries, a new lithium-ion pack does not need cycling through charging and discharging. Priming will make little difference because the maximum capacity of lithium-ion is available right from the beginning. Neither does a full discharge improve the capacity of a faded pack. However, a full discharge/charge will reset the digital circuit of a 'smart' battery to improve the state-of-charge estimation"
Click to expand...
Click to collapse
well thats certainly odd since i bought 2 OEM replacement batteries and used one out of the box til it died without charging it and it now wont hold a charge. Just coincidence that the one i did that to was a lemon?
Extended Battery Comments
adridge said:
You can also get the extended battery for <$50 which I heard helps a bunch.
Click to expand...
Click to collapse
I purchased the BP7X extended battery from a local Verizon store for $37 with corporate discount. It makes a HUGE difference. With corporate e-mail, two POP accounts at 30-minute intervals, and about 2 hours of music playing, I had 40% left after 12 hours yesterday. I know some people want to see more than that left, but coming from a number of -gasp- Windows Mobile devices, this is pretty much what I'm used to.
T BP7X is 1820/1860mAh, vs. the stock BP6X at 1390/1420mAh. I've seen other batteries listed with as much as 3500mAh. I would think such a battery would get one throught the day with very heavy usage, but I don't want to think how large that battery door would have to be!
The first post at this link shows a comparion of a D2 with the normal battery door and the Moto/VZW extended door. As somebody posted somewhere, the extended door actually makes the device "feel" better in the hand.
https://supportforums.motorola.com/message/224663
I'm new to this phone, and still learning my way around a bit. A couple of items that I'm wondering about...
1) When my battery starts getting low, and it goes into power saver mode, there is a button I can hit that says "Battery Info." It seems to almost be like the battery history in Spare Parts, which is nice, since Spare Parts doesn't work. However, I'm not absolutely certain how to interpret this data. Is it telling me what percent of my battery drain has been due to certain apps? Or is it telling me what percent of the time they have been running? Also, how can I get to this information when I'm not in power saver mode?
2) On a related note, what is considered to be typical battery life for this phone? I know that's a completely loaded question and differs by use. But maybe like a min/max range? And what things can I tweak to maximize battery life?
Many thanks.
flu13 said:
I'm new to this phone, and still learning my way around a bit. A couple of items that I'm wondering about...
1) When my battery starts getting low, and it goes into power saver mode, there is a button I can hit that says "Battery Info." It seems to almost be like the battery history in Spare Parts, which is nice, since Spare Parts doesn't work. However, I'm not absolutely certain how to interpret this data. Is it telling me what percent of my battery drain has been due to certain apps? Or is it telling me what percent of the time they have been running? Also, how can I get to this information when I'm not in power saver mode?
2) On a related note, what is considered to be typical battery life for this phone? I know that's a completely loaded question and differs by use. But maybe like a min/max range? And what things can I tweak to maximize battery life?
Many thanks.
Click to expand...
Click to collapse
1) to get into the battery stats go into Menu*Settings*About Phone*Battery*Battery Use* and its my understanding that the percentage shown for each app/task shows how much of a percentage of the battery that has been used was used by said task so right now my display shows 58% and im at 36% battery so 58% of the used battery was due to my display, then if i click on display it shows a time for how long an app/task has been active, so in my case phone has been on for 9 hours and display has been used for 4 hours i hope that helps
2)Battery life on the Shift is pretty solid im still at 35% and my phone hasnt charged since yesterday at about 6pm and i used it till maybe 2 am went to bed no charge woke up used the phone for about 30 minutes and have been on tapatalk and gtalk, facebook...the longest standyby i have had with my shift is 48 hours of very light usage but i normally get about 8-10 hours of extreme usage, so if your not a power user you should see some amazing battery life
Sent from my Supreme Shift using Tapatalk
Awesome. Thanks. That battery history thing blows Spare Parts out of the water.
Hi alI, I have a query regarding battery percentage drop. I’ve noticed that I can be using my Mate 9 for about 20 to 25 minutes and the battery percentage doesn’t drop at all, then it will drop about 3% or 4% in about 3 mins. I’ve had this phone for about ten days now but this wasn’t happening for the first week. Has anyone else noticed this? I know smartphones have issues generally with accurate battery percentage readings, so is this normal or a potential issue?
I've been told I should run my battery down completely and recharge all the way to 100% as it could be that my phone needs to re-calibrate, could this help?
Thanks.
Sounds to me like that drop is just a small delay in registering the previous use.
As you say, it's very difficult to measure battery charge accurately. The battery is not a precise electronic component like every other part of the phone. It's a box of messy chemicals, and no two are precisely the same.
If you discharge the battery fully and then charge it fully, that will give the most accurate calibration. But it still won't be perfect.
First of all, i have removed the battery from the tablet and i am supplying energy from the battery terminals (in this case, i want to be able to use my charging socket for the “OTG function”)
Even though giving the constant 4.2 volt electricity with this technic, battery gauge still drains from the tablet
im using chinese branded device as tablet by the way.Device is rooted with Android 10 go edition in it.
Normally, it has 2000mAh battery and the draining speed/principle is same as the above scenario
i’m waiting for the solution ideas or any suggestions
What exactly are you trying to accomplish?
Lithium ion batteries should NEVER be directly charged with a power source. Tablets and phones have charging controllers that regulate the charging current and voltage to avoid overcharging the battery, which at best reduces battery life, and at worst can cause catastrophic failure - including explosion and fire.
V0latyle said:
What exactly are you trying to accomplish?
Lithium ion batteries should NEVER be directly charged with a power source. Tablets and phones have charging controllers that regulate the charging current and voltage to avoid overcharging the battery, which at best reduces battery life, and at worst can cause catastrophic failure - including explosion and fire.
Click to expand...
Click to collapse
First of all, thank you for thinking of me. I am an experienced electronic engineer and have knowledge of Li-ion batteries. For the project that I am working on, I have to not use batteries due to the variation in ambient temperature.
Since I know that a fully charged battery provides 4.2 volts of energy, i remove the battery and so, supply this voltage from the place where the battery should normally be inserted.
When I turn on the tablet, the battery percentage shows 100%, after 20 minutes it drops to 85% approximately.
I don’t give the direct energy to the battery btw, on the contrary, i’m giving the energy from another source that the battery should normally give.
The attached photo can help you to have an idea for the situation
I just need to prevent the system for lowering the battery level as if like there is still battery in the tablet
brkedmrts said:
First of all, thank you for thinking of me. I am an experienced electronic engineer and have knowledge of Li-ion batteries. For the project that I am working on, I have to not use batteries due to the variation in ambient temperature.
Since I know that a fully charged battery provides 4.2 volts of energy, i remove the battery and so, supply this voltage from the place where the battery should normally be inserted.
When I turn on the tablet, the battery percentage shows 100%, after 20 minutes it drops to 85% approximately.
I don’t give the direct energy to the battery btw, on the contrary, i’m giving the energy from another source that the battery should normally give.
The attached photo can help you to have an idea for the situation
I just need to prevent the system for lowering the battery level as if like there is still battery in the tablet
Click to expand...
Click to collapse
Oh okay, I suspected that's what you were doing, I was just trying to make sure in the interest of safety and all that. It's all fun and games until someone gets hurt...
It's really hard to say why the battery gauge reports 85% even though you're supplying 4.2 volts of power. Depending on the firmware, Android battery gauges aren't simple voltmeters that simply display a percentage based on a certain voltage curve. They're a bit more advanced than that, and factor in the load on the battery too.
Here is a better explanation on how the systems work.
I would like to add another question that makes me wonder, will the battery percentage stay constant somewhere and/or will it start to rise after some point?
If there is no way to prevent the battery from decreasing in terms of software, I don't want the screen to go black when it reaches 15% and turn off at 0%. I'm going to make a supercapacitor and a modification to charge.
Or if I arrange the android as if there is a battery near infinity, I think that I can almost stop the battery percentage decrease rate, is that logic possible?
Up
brkedmrts said:
I would like to add another question that makes me wonder, will the battery percentage stay constant somewhere and/or will it start to rise after some point?
Click to expand...
Click to collapse
I honestly don't know.
brkedmrts said:
If there is no way to prevent the battery from decreasing in terms of software, I don't want the screen to go black when it reaches 15% and turn off at 0%. I'm going to make a supercapacitor and a modification to charge.
Or if I arrange the android as if there is a battery near infinity, I think that I can almost stop the battery percentage decrease rate, is that logic possible?
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If you're powering the device via a constant DC supply that doesn't drop voltage under load, I would imagine the battery indicator would eventually stop at some point and just remain at a certain percentage. Again, this depends on what sort of controller the device has; if it's an adaptive learning battery management system, it might be ignoring the supply voltage, and is calculating how much power the device has used so far. Eventually it'll figure out that the voltage isn't dropping as expected, but I have absolutely no idea what it'll do.
I'd say just leave it playing video or something for a while and see what happens.
V0latyle said:
I honestly don't know.
If you're powering the device via a constant DC supply that doesn't drop voltage under load, I would imagine the battery indicator would eventually stop at some point and just remain at a certain percentage. Again, this depends on what sort of controller the device has; if it's an adaptive learning battery management system, it might be ignoring the supply voltage, and is calculating how much power the device has used so far. Eventually it'll figure out that the voltage isn't dropping as expected, but I have absolutely no idea what it'll do.
I'd say just leave it playing video or something for a while and see what happens.
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Click to collapse
I had decided to try my super capacitor idea. However, For a device whose charge level drops while charging with its original battery installed, this was not very wise.
but I added a capacitor as shown in the attached image and I've been testing it for 25 minutes.
battery percentage 99% for last 20 minutes.I t hope I managed to manipulate it somehow.
I will be sharing the results,Also, thank you for your interest.
brkedmrts said:
I had decided to try my super capacitor idea. However, For a device whose charge level drops while charging with its original battery installed, this was not very wise.
but I added a capacitor as shown in the attached image and I've been testing it for 25 minutes.
battery percentage 99% for last 20 minutes.I t hope I managed to manipulate it somehow.
I will be sharing the results,Also, thank you for your interest.
Click to expand...
Click to collapse
Hey there, were you able to work it out?