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Charging the battery with phone off makes it last longer?

Havent you noticed that when you charge the phone powered off it takes like 40 % more time for the batetry to charge but it also makes the battery last longer? is there any truth in this or im just crazy?

Chad_Petree said:
Havent you noticed that when you charge the phone powered off it takes like 40 % more time for the batetry to charge but it also makes the battery last longer? is there any truth in this or im just crazy?
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This is a very well know issue related to battery calibration. Take a look at the many calibration threads to learn about bump charging.
Basically, it takes longer with the phone off (or when you pull and put back the battery while charging) because in some cases android was stopping the charge before a full charge.
Try this
Charge your phone to 100% (inside android)
Turn you phone off
Reboot
Pull the battery before it boots
Wait for the ?
Put the battery back in and notice the %
If it says 60%, then you had 40% of your battery not being charge.
If you leave it in that spot and wait for it to go to 100%, your battery will be better calibrated.
Sent from my Milstone running CM7

Caz666 said:
This is a very well know issue related to battery calibration. Take a look at the many calibration threads to learn about bump charging.
Basically, it takes longer with the phone off (or when you pull and put back the battery while charging) because in some cases android was stopping the charge before a full charge.
Try this
Charge your phone to 100% (inside android)
Turn you phone off
Reboot
Pull the battery before it boots
Wait for the ?
Put the battery back in and notice the %
If it says 60%, then you had 40% of your battery not being charge.
If you leave it in that spot and wait for it to go to 100%, your battery will be better calibrated.
Sent from my Milstone running CM7
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Click to collapse
and this hasnt been fixed even with gingerbread? yeah i have gotten the message saying it has 60 % :/

I pay no attention to the battery meter anymore. I've found that it just reads low. It's not that it doesn't get a fully charge, the phone can't read the level correctly. I tried draining the battery once by playing an episode of Top Gear with the screen on full brightness. The phone said the battery was at 5% but the video kept playing for another 1.5 hours.

baoli said:
I pay no attention to the battery meter anymore. I've found that it just reads low. It's not that it doesn't get a fully charge, the phone can't read the level correctly. I tried draining the battery once by playing an episode of Top Gear with the screen on full brightness. The phone said the battery was at 5% but the video kept playing for another 1.5 hours.
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Click to collapse
noup , when my batetry says low , it dies pretty quickly

Go with mV.
4200mV=100%
3200mV=0%
Battery monitor widget kicks ass

zeppelinrox said:
Go with mV.
4200mV=100%
3200mV=0%
Battery monitor widget kicks ass
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Click to collapse
mV?

Chad_Petree said:
mV?
Click to expand...
Click to collapse
millivolt. there are other ways to read out this value... I'm using osmonitor, since it's installed anyways

[Q]Battery indicator showing wrong?

The last couple of days I've got a weird problem. When my battery is fully charged everything seems okay and it drains in normal speed (compared to stock).
But when my phone runs out off battery and i start to charge in the beginning everything seems fine.
But suddenly it can go from 75 to 100% in 1 minute.When i look at the stats in MIUI ROM it seems like it's not at same height as it was the last day of 100%. Maybe only 80%.
Sorry for my bad English, but i hope it makes sense.
I've wiped battery stats in CWM. But is it possible that the phone actually is only 80% charged, even though the indicator shows 100% after wipe?
Because if the ROM think the battery is charged and wipe stats it will afterwards only charge to that point and the battery maximum will decrease over days?
If that's possible, how do i full charge the battery? Just leave it in the charger or?
I hope you can understand what I mean.
Thanks in advance

Hello
Does your phone charge to fx 75% and after that doesnt get higher until after you restart the phone?
Sent from my LG-P990 using XDA App

CescMusta said:
Hello
Does your phone charge to fx 75% and after that doesnt get higher until after you restart the phone?
Sent from my LG-P990 using XDA App
Click to expand...
Click to collapse
Yes excactly. But the numbers differs.
Today it charged to 100% though.
Got the same problem?
Sent from my Optimus 2X using XDA App

have you try calibrate your batt again
yes my friend have this problem too, maybe there is software bug

After flashing Celebration HD 2.0.1b I first used Battery Calibration from market to wipe battery stats. Afterwards the battery indicator problems started.
Yesterday i decided to wipe battery stats manually in CWM and drain to phone to 2% before charging, and afterwards I was able to fully charge the phone.
So maybe the bug in is Battery Calibration app?
I decided to install Juice Plotter to monitor the battery and compare it to one build in in MIUI. Just to get some more data.

Hello again
Yes i had the same problem as you, with my previosly 2 lg optimus 2x, and returned them because of the problem you mentioned. I am on the third op2x and luckily this work good
So if i were in your position i would try to go to the dealer and shift the phone with another lg optimus 2x.
Best regards
Sent from my LG-P990 using XDA App

CescMusta said:
So if i were in your position i would try to go to the dealer and shift the phone with another lg optimus 2x.
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Click to collapse
The user said that he started to have problem after a new rom and wiping battery stats, changing phone for that is not the smartest move at all. Is like changing phone because your rom doesn't work.
I have a similar problem, after you wipe battery stats you don't have a reliable indicator, for me the phone took 3 hours to get from 99 to 100%.
I also noticed that my miui ( 1.8.5 same for 1.7.29) doesn't update battery stats when the screen is off so all those plotter don't work, and i think this messes up with the battery indicator (I guess the phone doesn't have enough data to make a decent estimate)
I think is miui + wipe battery stats that can be problematic

I know that but i am just saying that i also had the same problem with the stock rom.
Best regards
Sent from my LG-P990 using XDA App

How old is the battery? How many cycles does it have?
I know from laptop Li-Ion batteries that the voltage vs. capacity is not linear.
When discharging, the voltage will steadily drop to a "wear-level" where it will jump to an almost depleted level. When charging, this "wear-level" will be at the top.
Why I am telling this? Because if this mapping is kept in SW and you wiped it, Android needs to relearn it again. So at 1st complete charging/discharging you would see a % sudden drop/raise, but at the next cycles it would be linear with time (although the total time will be smaller than a new battery).
When laptop/phone battery tips talk about calibration, it is so whoever monitors the voltage (circuit in battery or SW) to know were the wear drop will be, so your estimates to be better.
As an example, I had a very old Thinkpad that did not have any calibration, and it would discharge to about 40% and drop to 5% within seconds. But when charging, it would raise steadily to 70% (from that 5%) but 70% to 95% in seconds. After years of use, that percentage gap would just increase (40-5 got 60-5, 70-5 on discharging).
PS: my current Thinkpad has 4 years and the battery capacity is 49% with 150 cycles. But this one has a nice feature where if the battery was above a certain percentage, plugging AC would not charge it (and thus save a few cycles). I used it set at 70%.
PS: LiIon batteries have cycle count, heat and time as main enemies. Also don't like prolonged (think storage) low charge.

battery on wallcharger screen of error
CenaDK said:
The last couple of days I've got a weird problem. When my battery is fully charged everything seems okay and it drains in normal speed (compared to stock).
But when my phone runs out off battery and i start to charge in the beginning everything seems fine.
But suddenly it can go from 75 to 100% in 1 minute.When i look at the stats in MIUI ROM it seems like it's not at same height as it was the last day of 100%. Maybe only 80%.
Sorry for my bad English, but i hope it makes sense.
I've wiped battery stats in CWM. But is it possible that the phone actually is only 80% charged, even though the indicator shows 100% after wipe?
Because if the ROM think the battery is charged and wipe stats it will afterwards only charge to that point and the battery maximum will decrease over days?
If that's possible, how do i full charge the battery? Just leave it in the charger or?
I hope you can understand what I mean.
Thanks in advance
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Click to collapse
I have when i turn off my fhone and i charge it it shows a battery icon whit an error in it ics lgp990 please help i dont no what tho do

Swapping batteries

What is the best way to swap batteries with different capacity?
I noticed then when you put a new one it retains the old %. Wiping the battery stats helped a little but the reading is still incorrect because the phone stayed on web surfing in 3g for 30m with 1% which is impossible.
Also what app can I use to test the battery duration? like a stress tool that does the same thing in cycles so I can see which battery lasts more.

Just use the phone normally, after a few charging cycles the readings will match the actual %. Wiping battery stats doesn't really help, as it is not really related to reading the battery's state as some people used to believe.
Use the Battery Drain app by Waza_Be found in Google Play. It records the time every 1% decrease, letting you to know how long 1% of your battery lasts

Like silentmelodies said,
this will settle with your battery being fully charged a few more times.
I am using battery calibration app everytime I install a new rom.

It doesn't work The indicator is stuck at the previous level

Leave the battery out for at least 15 seconds before inserting the new battery. Then you'll get the correct reading. Don't be quick ;-)

TrymHansen said:
Leave the battery out for at least 15 seconds before inserting the new battery. Then you'll get the correct reading. Don't be quick ;-)
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Click to collapse
Yep, what I also do is tap the power button to clear any residual charge, seems to allow me to change batteries faster.

its bad practice, but I pull the battery out with the phone on, but screen off. the new battery will show the correct percentage...

kemmo123 said:
its bad practice, but I pull the battery out with the phone on, but screen off. the new battery will show the correct percentage...
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Click to collapse
Yes it's a really bad practice!
Inviato dal mio LG-P990

Battery is discharging very fast

Hello I have a problem with my 4 month Nexus 7 3G. I noticed that recently the battery drains very fast in standby mode - for example 6-7% per hour. I installed better battery stats to see the deep sleep time and kernel/partial wakelocks... For example the tablet is 1hour and 20 mins in deep sleep and 1 min awake and has gone from 100 to 94 just in hour... Put the the tablet in Airplane mode, did hard reset, reflashed stock rom - no go... Is it possible that my battery has failed? And is it covered by warranty?

kopchev said:
Hello I have a problem with my 4 month Nexus 7 3G. I noticed that recently the battery drains very fast in standby mode - for example 6-7% per hour. I installed better battery stats to see the deep sleep time and kernel/partial wakelocks... For example the tablet is 1hour and 20 mins in deep sleep and 1 min awake and has gone from 100 to 94 just in hour... Put the the tablet in Airplane mode, did hard reset, reflashed stock rom - no go... Is it possible that my battery has failed? And is it covered by warranty?
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Click to collapse
Read the first post in the BBS thread, do it. Post the log to their thread. Perhaps they can come up with something.
First thing I'd try is turning off wifi while it's asleep and see what happens. I've always turned off wifi while my tablets slept and I see about 1% every 6 or so hours, at most.

I factory reseted the tablet, switched the cellular off, the wifi off, turned off sync, didn't install or update any program... I put it in standby mode and after 57 mins it was 5% down. No kernel wakelocks, nothing at all, just deep sleep.

As with any form of problem isolation, you are going to try a few experiments to figure out where the problem is... and where it isn't.
If the problem is the battery itself, it will self-discharge even when the tablet is off and disconnected. (Not only that but the battery might be slightly warm when disconnected, but it might be hard to detect that without an IR Camera).
One experiment to eliminate this possibility is to charge the battery, turn the tablet off, and disconnect the battery overnight. Reconnect the battery, boot the tab, and then examine
the change in battery VOLTAGE, NOT "percent charge" *
You can use something like the app "Current Widget" to read the before/after voltage.
Note that you can't just turn the tablet off in this experiment without disconnecting the battery connector, as there is a possibility the the motherboard has a defect that drains power even when the tablet is off; although if you run this first experiment and find no drop in (unplugged) battery voltage, then doing this ("does the battery voltage fall a lot with the device turned off?") is a useful 2nd experiment.
*The TI BQ72451 battery charge controller IC attempts to gauge battery state by measuring both voltage and cumulative charging/discharging currents (by measuring voltage across a small resistor in the battery terminal path). This means that it is stateful (it has onboard flash memory) and more importantly that the "% charge" value this circuit produces is a computed value, not a measured value. If you are experiencing battery problems, the % charge value should be regarded with some amount of suspicion. For a healthy battery with about a 0.6-0.7v range (say 3.5v-4.2v), a 10% drop in battery capacity will be roughly a drop of about 0.06 volts.
This isn't a solution - but a place to start to eliminate some possibilities.
good luck
PS what does
Code:
$ cat /sys/class/power_supply/battery/health
return? (Should say "Good")

My tablet does the exact same thing. My battery average is 20 hours with use.
Sent from my Nexus 7 using xda premium

It says the battery health is good. I tried everything - reflashed the factory image, even 4.2.1 image, reset to factory defaults, removed the sim, switched off the wifi/nfc/3g... it drains exactly 5%/h in standby and the battery grafic show straight line downwards...The betterbattery stats says the 99% of time the tablet spends deep sleep. I came to the following conclusions: a) the battery has failed, b) the chip (or component) reading the battery stats is faulty c) a hardware defect that drains battery...It's not software since there are no indications that any piece of software is draining the batt.

If you turn the tablet completely off, let it sit for a few hours, and then boot the tablet, does it also lose charge this way as well?
How about if you do the above experiment - but unplug the battery completely instead of simply turning the tab off?
Doubtful this will fix anything, but it will give you more info about where the problem lies.
Along this same line of thinking, I note you have said nothing about voltages. Imagine that the charge controller chip thought that the 100% charge state was a lower voltage than what it should be - this would show up as anomolously large discharge rates (%/hr) even if the current draw was nominal.
I think 100% should be around 4150-4200 mV, and 5% around 3500 mV. (You can use the "Current Widget" app to observe the voltage in a convenient way.)
good luck

bftb0 said:
If you turn the tablet completely off, let it sit for a few hours, and then boot the tablet, does it also lose charge this way as well?
How about if you do the above experiment - but unplug the battery completely instead of simply turning the tab off?
Doubtful this will fix anything, but it will give you more info about where the problem lies.
Along this same line of thinking, I note you have said nothing about voltages. Imagine that the charge controller chip thought that the 100% charge state was a lower voltage than what it should be - this would show up as anomolously large discharge rates (%/hr) even if the current draw was nominal.
I think 100% should be around 4150-4200 mV, and 5% around 3500 mV. (You can use the "Current Widget" app to observe the voltage in a convenient way.)
good luck
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Click to collapse
Hi, I tested the things u mentioned. The n7 charges until it reaches 4200 MV. It doesn't drain battery when powered off. Here are screenshots of usage:

kopchev said:
Hi, I tested the things u mentioned. The n7 charges until it reaches 4200 MV. It doesn't drain battery when powered off. Here are screenshots of usage:
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Click to collapse
Note that the charger chip may not report a "% charge" drop even if the battery is self-discharging with the device off, as no current is detected in the battery lead. Hopefully what you mean by "doesn't drain" is "voltage didn't fall".
Well, I guess you now know that the problem probably is not the battery (although you should still confirm that the almost-discharged voltage is down around 3.5v).
Doesn't solve your troubles though. That 5%/hr drain with the tablet sleeping should be closer to 5% in 12 hours, so your tablet is doing at least 10x worse than it should.
Warranty return to Asus at this point?

Will relock the bootloader and return it to the Asus authorized service in bulgaria.

kopchev said:
Hi, I tested the things u mentioned. The n7 charges until it reaches 4200 MV. It doesn't drain battery when powered off. Here are screenshots of usage:
Click to expand...
Click to collapse
wow, that is something. very nice discharging graph.

A nicer discharging graph...
ando1993 said:
wow, that is something. very nice discharging graph.
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Click to collapse
Here is the graph after I factory reseted the N7 chrged to full and turned off the screen.

I've seen my battery standby performance get worse these last couple of weeks - I used to get between 5-7 days of standby time on a charge, if left unused, but the last few weeks it only goes for 2/3 days now, not sure what's changed...

NFC services were killing mine... Shut NFC off, killed the service, and it's been great for the last few days.

What is the average battery stats for nexus 7 ..
Sent from my Nexus 7 using xda premium

if you go into maps.....settings...location settings...uncheck all options, that seemed to do the trick for me

It's most likely the baseband_xmm_power wakelock, it's a nasty one. It comes and goes when it likes. Google hasn't come out with a fix yet. Reverting to stock doesn't help it. the only fix is to run Franco kernel, he patched it.
.Sent from my Nexus 7 using xda app-developers app

androo45 said:
It's most likely the baseband_xmm_power wakelock, it's a nasty one. It comes and goes when it likes. Google hasn't come out with a fix yet. Reverting to stock doesn't help it. the only fix is to run Franco kernel, he patched it.
.Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Mkernel also has it fixed, same with trinity and dmore kernel and I'm pretty sure faux kernel does as well, as for the stock kernel, it does not have the fix
Sent from my Nexus 7 using xda app-developers app

My battery was being murdered. Eventually I traced it to having Beautiful Widgets on the lock screen. Removed that and battery life is fantastic again. Are others using widgets on the lockscreen?

Try wakelock detector from playstore which will find you your wakelocks...

Inaccurate battery %??

After charging my battery fully to 100%, I unplug it from the charger and without even turning the screen on, the battery drains to 92% within one hour. I check the battery stats and there are maybe only a couple wakes during this time.
Sometimes, the battery shows a certain percentage longer than others. Example, my phone will be on 65% longer than it would be on 60%.
Battery still gives me a solid 2 days usage with about 3+ hours screen on time. The service menu also says that the battery is good.
Is there a way to get the battery reading to show more accurately?
Thanks,

Hope I could Help You
For your battery problem, I guess you could try calibrating it. And also try to install "Greenify" along with "Clean Master or 360 Security" and try to close all running apps before turning off the screen. I also turn on Stamina Mode when the battery is at 100%, in an attempt to further save battery life. And the result has been kinda meh, but well, battery drains about 1% per hour. It lasts about a day and half with light usage. In my case, light usage being, browsing, youtube videos for about 2 hours, listening to music, social networking and taking some pictures
Squatrack Curler said:
After charging my battery fully to 100%, I unplug it from the charger and without even turning the screen on, the battery drains to 92% within one hour. I check the battery stats and there are maybe only a couple wakes during this time.
Sometimes, the battery shows a certain percentage longer than others. Example, my phone will be on 65% longer than it would be on 60%.
Battery still gives me a solid 2 days usage with about 3+ hours screen on time. The service menu also says that the battery is good.
Is there a way to get the battery reading to show more accurately?
Thanks,
Click to expand...
Click to collapse

jeseunpark said:
For your battery problem, I guess you could try calibrating it. And also try to install "Greenify" along with "Clean Master or 360 Security" and try to close all running apps before turning off the screen. I also turn on Stamina Mode when the battery is at 100%, in an attempt to further save battery life. And the result has been kinda meh, but well, battery drains about 1% per hour. It lasts about a day and half with light usage. In my case, light usage being, browsing, youtube videos for about 2 hours, listening to music, social networking and taking some pictures
Click to expand...
Click to collapse
Hey,
im using greenify (my phone is rooted). Battery is quite good for me though. I get about 3 days with light usage. I start charging my phone again when the battery gets to anywhere between 10-20%.
I read that maybe its better not to let it get so low?
I have no wake locks either.

Umm.. IMO, 10-20% is okay. I usually charge the phone when the battery gets around 5%. I read somewhere that charging battery too early can affect the battery's overall standby time (reducing it). It's better not to let the battery reach 0% though.
I had that happen with my Samsung Galaxy Note 2 earlier. I once let the battery dip all the way to 0% many times. After a few charge cycles, I found out that the battery was dead and wouldn't charge at all so I ended up buying a new battery :-/
Umm.. Coming back to our Z1's, could you try putting the phone in stamina mode everytime the phone is kept on standby mode? This boosted my battery life a lot I even put my phone on stamina mode throughout the whole night yesterday to test the battery life again, and when I switched on in the morning, I saw that the battery had dipped by just 2% (standby time of 7 hours). I'm really confused how your battery drops so fast, 100% to 92%.
Could you try calibrating the battery and then putting it in Stamina Mode while on Stanby and tell me the results? I hope I could help :fingers-crossed:
Squatrack Curler said:
Hey,
im using greenify (my phone is rooted). Battery is quite good for me though. I get about 3 days with light usage. I start charging my phone again when the battery gets to anywhere between 10-20%.
I read that maybe its better not to let it get so low?
I have no wake locks either.
Click to expand...
Click to collapse

jeseunpark said:
Umm.. IMO, 10-20% is okay. I usually charge the phone when the battery gets around 5%. I read somewhere that charging battery too early can affect the battery's overall standby time (reducing it). It's better not to let the battery reach 0% though.
I had that happen with my Samsung Galaxy Note 2 earlier. I once let the battery dip all the way to 0% many times. After a few charge cycles, I found out that the battery was dead and wouldn't charge at all so I ended up buying a new battery :-/
Umm.. Coming back to our Z1's, could you try putting the phone in stamina mode everytime the phone is kept on standby mode? This boosted my battery life a lot I even put my phone on stamina mode throughout the whole night yesterday to test the battery life again, and when I switched on in the morning, I saw that the battery had dipped by just 2% (standby time of 7 hours). I'm really confused how your battery drops so fast, 100% to 92%.
Could you try calibrating the battery and then putting it in Stamina Mode while on Stanby and tell me the results? I hope I could help :fingers-crossed:
Click to expand...
Click to collapse
Yeah i could try to calibrate it. Im a little confused on what you do to calibrate the battery (ive read way to many opinions on this). Can you please tell me the steps.

Squatrack Curler said:
Hey,
im using greenify (my phone is rooted). Battery is quite good for me though. I get about 3 days with light usage. I start charging my phone again when the battery gets to anywhere between 10-20%.
I read that maybe its better not to let it get so low?
I have no wake locks either.
Click to expand...
Click to collapse
Squatrack Curler said:
Yeah i could try to calibrate it. Im a little confused on what you do to calibrate the battery (ive read way to many opinions on this). Can you please tell me the steps.
Click to expand...
Click to collapse
I used this to help me - http://forum.xda-developers.com/showthread.php?t=1024867