Nexus 7 Battery issues - Nexus 7 Q&A, Help & Troubleshooting

Haven't switched from the OEM charging cord so I don't know why my battery meter showed that I remained at 22% for more than 3 hours...
All day yesterday the only time the percentage would go above that was when I put the tablet down completely, killed all apps and processes and shut off wifi....I've never had to do so much just to see an increase So I attempted to recalibrate and wipe battery stats in cwm for the first time as I have done on all my other devices...
With most if not all devices the fastest way to charge is with the device powered off....for the strangest reason the N7 charges faster with the power on. Ive had this thing plugged in for 5 hours from a fully discharged state and the batter meter only reads half....whats taking so long? With the device on all i need is 2.5-3 hours....Can someone explain this as i have combed Google search like mad looking for an answer...
Sent from my Nexus 7 using xda app-developers app

oneG said:
All day yesterday the only time the percentage would go above that was when I put the tablet down completely, killed all apps and processes and shut off wifi....I've never had to do so much just to see an increase So I attempted to recalibrate and wipe battery stats in cwm for the first time as I have done on all my other devices...
Click to expand...
Click to collapse
Looks like you missed the memo...
Wiping battery stats does not affect battery indication in any way, shape, or form, nor can you actually ”recalibrate” your battery. The misinformation regarding wiping battery stats was emphatically debunked by Google's Android team about a year ago.
Rather than wasting time with snake oil such as ”calibration” and wiping battery stats, more viable solutions are a factory reset or ensuring your battery connector is fully seated on the mainboard.
Sent from my Nexus 7 using Tapatalk HD

Related

Wipe battery stats made it worse

I followed directions on what I thought to be a battery fix, but it ended up making my battery life twice as bad. Actually it takes longer to charge now than it does to drain.
Anyone else have this happen?
Sent from my ADR6300 using XDA App
I did the same thing, but I've only charged once and I didn't time it. I haven't been timing any of my charges or discharges, but maybe give it some more time, that's kind of how stats work isn't it....usage over time? Good luck.
Today I started at 100% (not a powered off full charge though). After 2 hours of moderate use I was down to 50%. I have been charging for an hour via car charger and currently at 67%.
Sent from my ADR6300 using XDA App
Not to be a dink, but then it would appear that you didn't follow the instructions. As a result, YMMV I guess.
1. You will need to charge the phone to 100% (while the phone is off).
2. Leave charging cable plugged in.
3. Boot into recovery and wipe the battery stats (should be under Advanced).
4. Then boot into Android.
5. Then remove the charging cable.
Click to expand...
Click to collapse
Give it another shot, and I would suggest that maybe it not be thought of as a "fix". Try using the wall charger as well. I only use the wall charger as I have a converter in my vehicles. Let us know how it goes!
Wynnded said:
Not to be a dink, but then it would appear that you didn't follow the instructions. As a result, YMMV I guess.
Give it another shot, and I would suggest that maybe it not be thought of as a "fix". Try using the wall charger as well. I only use the wall charger as I have a converter in my vehicles. Let us know how it goes!
Click to expand...
Click to collapse
Those are actually the directions that I followed yesterday afternoon. I didn't notice the battery life being any different after doing that initially. At the end of the day I charged my phone via wall charger for roughly 8 hours while I slept.
I was unplugged for less than two hours and watched it drop down 50%. Wifi was off, Gps also off. I was doing some web browsing and also using the xda app. I played a game for a couple of minutes.. That was it. I really should've checked the battery usage but I didn't think of it in time.
I only charged it in the car today out of necessity because of the super quick discharge. When I'm at home I only charge with the wall charger.
Sent from my ADR6300 using XDA App
I'd venture a guess that you have something else running the background. I honestly wish that I had something more for you, but I'm going to have to fold.
Wynnded said:
I'd venture a guess that you have something else running the background. I honestly wish that I had something more for you, but I'm going to have to fold.
Click to expand...
Click to collapse
I've heard others say they found facebook or twitter running in the background and that when they killed that it made a big difference in battery life. Perhaps that?
WiFi set to never turn off
I noticed this morning that WiFi had been set to never sleep, I just changed that t 15 min.
Had a full 100% charge last night did not leave on the charger, minimal use this morning down to 78%.
Let's see how the new WiFi settings works.
oldman_58 said:
I noticed this morning that WiFi had been set to never sleep, I just changed that t 15 min.
Had a full 100% charge last night did not leave on the charger, minimal use this morning down to 78%.
Let's see how the new WiFi settings works.
Click to expand...
Click to collapse
that doesn't do anything unless you leave wifi on all the time, and if you do then that would be one solution to this problem.
htc_woe_is_me said:
Those are actually the directions that I followed yesterday afternoon. I didn't notice the battery life being any different after doing that initially. At the end of the day I charged my phone via wall charger for roughly 8 hours while I slept.
I was unplugged for less than two hours and watched it drop down 50%. Wifi was off, Gps also off. I was doing some web browsing and also using the xda app. I played a game for a couple of minutes.. That was it. I really should've checked the battery usage but I didn't think of it in time.
I only charged it in the car today out of necessity because of the super quick discharge. When I'm at home I only charge with the wall charger.
Sent from my ADR6300 using XDA App
Click to expand...
Click to collapse
I experienced the exact same issue after doing the battery thing yesterday. Tried several different kernals since then - no change: I could just about watch the battery go down. This morning I wiped and loaded SR Sense 2.5.2 and the updated stock kernal from ROM manager. We'll see how it goes...
rfarrah said:
I experienced the exact same issue after doing the battery thing yesterday. Tried several different kernals since then - no change: I could just about watch the battery go down. This morning I wiped and loaded SR Sense 2.5.2 and the updated stock kernal from ROM manager. We'll see how it goes...
Click to expand...
Click to collapse
I did this and just installed 2.5.2. I then installed the Hydra kernel and wiped battery stats when I was at 100% and the unit was off/green light. The battery has gone to crap too. Any ideas?
thats weird, i did wipe battery stats (correctly) at 11 last night. i woke up at 9:30 (lol) with 93% battery left. the phone was sleeping the whole time, but i had sync turned on and had recieved several facebook updates, txts, and emails. now im losing around 10%battery every two hours or so, and i am using the phone to send txts and emails every three to five minutes. so battery life is actually much better. after the cable is unplugged, is it necessary to let the battery die fully, then charge, or can i charge it now? (its at around 30%)
so basically, i was wondering if it is necessary to run your battery fully down after doing a wipe battery stats
I don't know what to tell you guys. Since wiping stats, my phone has been up for 36 consecutive hours with an awake time of 2:40 and the battery is at 30%.
For reference I guess....
SLOflatlander said:
so basically, i was wondering if it is necessary to run your battery fully down after doing a wipe battery stats
Click to expand...
Click to collapse
Great question. Anyone have any knowledge on this? I didn't let mine discharge all the way.
I do have some kind of update. I had to do a factory wipe today and since I did that my battery life has been much better.
Sent from my rooted Incredible using XDA App
Has anyone else done this that can report there results?
I was about to do this but now I am skeered.
It's completely impossible for wiping your battery stats to make your battery life worse. It's a common misconception that by wiping your battery stats you somehow condition your battery. It's actually quite the opposite, because you're actually conditioning Android by wiping your stats. No matter what your battery percentage or meter says, your battery is still capable of holding a certain amount of electrical charge and your phone will not die until it's fully discharged. On the other hand it *might* make your percentage or battery meter read wrong if you either:
a. wiped your battery stats without a full bump charge (e.g. wiping your stats at 60% charge *might* make your phone think 60%=100% and as a result, you'd see huge decreases. but, you would most likely sit there with a phone showing a 1% charge for hours after it got there.)
b: didn't allow your phone to discharge fully after wiping your stats (same problem as example a, but the inverse of it)
All wiping your battery stats does is delete the file "batterystats.bin" from your /data/system folder. This file is recreated when you boot your phone after wiping them. It keeps the data on what's using your battery for when you click "battery use" in the settings menu. It's also thought to hold the stats that tell you phone what a full charge and no charge feels like and that if you fully bump charge your phone, wipe that battery stats, and then full discharge your phone (without interrupting it by switching ROMs or doing updates) that you will have a more accurate battery meter. It won't eliminate the need to bump charge your phone or make your battery life better. It will just be perceived as better since you won't get 20% drops in your reading in 30 minutes due to a badly calibrated batterystats.bin file. Also, you'll feel better because instead of looking at a 50% reading, you'll be looking at 60%.
Your battery still has the same capacity, charges to the same level, and discharges in the same amount of time. The only thing that can change those things are usage levels.
so should i redo my wipe battery stats then? when i originally did it, i ran it down to around 40%, then rebooted, then i plugged it in around 15%. would this mess it up then?
vantagejuan said:
It's completely impossible for wiping your battery stats to make your battery life worse. It's a common misconception that by wiping your battery stats you somehow condition your battery. It's actually quite the opposite, because you're actually conditioning Android by wiping your stats. No matter what your battery percentage or meter says, your battery is still capable of holding a certain amount of electrical charge and your phone will not die until it's fully discharged. On the other hand it *might* make your percentage or battery meter read wrong if you either:
a. wiped your battery stats without a full bump charge (e.g. wiping your stats at 60% charge *might* make your phone think 60%=100% and as a result, you'd see huge decreases. but, you would most likely sit there with a phone showing a 1% charge for hours after it got there.)
b: didn't allow your phone to discharge fully after wiping your stats (same problem as example a, but the inverse of it)
All wiping your battery stats does is delete the file "batterystats.bin" from your /data/system folder. This file is recreated when you boot your phone after wiping them. It keeps the data on what's using your battery for when you click "battery use" in the settings menu. It's also thought to hold the stats that tell you phone what a full charge and no charge feels like and that if you fully bump charge your phone, wipe that battery stats, and then full discharge your phone (without interrupting it by switching ROMs or doing updates) that you will have a more accurate battery meter. It won't eliminate the need to bump charge your phone or make your battery life better. It will just be perceived as better since you won't get 20% drops in your reading in 30 minutes due to a badly calibrated batterystats.bin file. Also, you'll feel better because instead of looking at a 50% reading, you'll be looking at 60%.
Your battery still has the same capacity, charges to the same level, and discharges in the same amount of time. The only thing that can change those things are usage levels.
Click to expand...
Click to collapse
Do you know how we can see what's inside the actual batterystats.bin file? I tried in root explorer and cannot open in no matter how I try.
i dont care what vantagejuan says, when i tried this process...and did it correctly, my battery was down to 85% within an hour..i know this because i unplugged it when i woke up for work, and i when i clocked in, it was at 85%
it was never this bad, i tried locating the file again from an old backup, but it didnt help...im hoping that like someone else said, a couple cycles through it will get better
im using the skyraider 2.5.2 vanilla with the hydra oc/uv kernal
i had this setup before AND after trying the battery fix and im using the seidio 1750...
frustrations are back from when i first got the phone

Proper way of calibrating battery?

Hi folks, I'm running CM6 8/26 nightly with Snap v7.4 kernel with SetCPU set to conservative on 998mhz max and 245mhz min. I'm getting horrid battery life and I think I'm doing something wrong: I wiped battery stats in Clockwork and now my battery SUCKS. -.-
Question is, what its the proper way of calibrating an Evo battery? I've seen the official HTC response but I don't think it's going to make a difference. Isn't there another method that requires you to drain the battery? Any info will be appreciated I've been looking at forums all day.
Sent from my PC36100 using XDA App
letshaveDEX said:
Hi folks, I'm running CM6 8/26 nightly with Snap v7.4 kernel with SetCPU set to conservative on 998mhz max and 245mhz min. I'm getting horrid battery life and I think I'm doing something wrong: I wiped battery stats in Clockwork and now my battery SUCKS. -.-
Question is, what its the proper way of calibrating an Evo battery? I've seen the official HTC response but I don't think it's going to make a difference. Isn't there another method that requires you to drain the battery? Any info will be appreciated I've been looking at forums all day.
Sent from my PC36100 using XDA App
Click to expand...
Click to collapse
You can't just wipe battery stats - there's a process to go through. What you're referring to is Cyanogen's battery recalibration method found here. Read through fully before wiping anything.
Thank u very much, I wiped the stats by mistake
Sent from my PC36100 using XDA App
fachadick said:
You can't just wipe battery stats - there's a process to go through. What you're referring to is Cyanogen's battery recalibration method found here. Read through fully before wiping anything.
Click to expand...
Click to collapse
Actually it is almost as simple as wiping battery stats. That command he gives is what the wipe battery stats command in the recoveries do.
1. Charge battery to full (where it's actually 100% not green light.
2. Boot into recovery wipe battery stats.
3. Fully boot into os then unplug charger.
4. Leave unplugged until the phone shuts itself off.
At that point you should be calibrated.
On a related topic, the Battery Graph app available in the market also has an option to wipe battery stats from within the OS, doesn't it? Might save having to reboot into recovery once you're charged up.
It's a lithium battery. You can't condition it. Just use it as normal and ignore all these placebo effect steps.
Sent from my PC36100 using XDA App
daving313 said:
It's a lithium battery. You can't condition it. Just use it as normal and ignore all these placebo effect steps.
Sent from my PC36100 using XDA App
Click to expand...
Click to collapse
This is all about calibrating the software (battery stats).
daving313 said:
It's a lithium battery. You can't condition it. Just use it as normal and ignore all these placebo effect steps.
Click to expand...
Click to collapse
They're not calibrating the battery. they're calibrating the phone to know when the battery is really fully charged which, until you do this, is not the case when the charge light turns green.
Regardless, none of this worked. I've quit all services, no sync, auto brightness and wifi and I'm still getting horrible battery life. SetCPU is set to conservative. It's BULL**** my display is on for thirty minutes and the battery dies 20%. I played a game on my friend's iPhone 4 for twenty minutes and his battery barely died 3%. This is really unacceptable and I'm probably going to return my Evo or sell it if the battery life doesn't get better soon from these methods I'm seeing online
Sent from my PC36100 using XDA App
Crazy man, maybe something happened cause that is pretty bad.
Have a backup to go back to, prior to this happening, to see if it reverts back to normal?
Naw nothing happened to my phone...... All of us Evo owners should be able to use this beautiful phone with all of the features at max without the battery going to ****. My phone has behaved this way since unboxing. I'm not a big fan of the iPhone 4 but I will give it props on battery life. I have yet to try the longer HTC method but it seems kind of pointless.....
Sent from my PC36100 using XDA App
If it has always been like that then you may have a bad battery, if it started after you wiped the battery data then it is just showing you bad readings.
You should be able to get a good calibration if you reset your battery data again, maybe try through your recovery if possible, and then fully charge it with your phone turned off. Once it is charged you can either use it normally till it dies or you can tether, use gps, watch youtube, etc, and drain the battery down. Just make sure you go from a full charge to the phone shutting itself off without plugging it in to anything. Do that charging with it off and using it till it dies two or three times and your battery stats will be calibrated.
When I did this to mine it showed my battery at 0% for at least half an hour before it finally died, and that was with me listening to pandora and browsing the web.
Edit: FYI, the Evo's talk time is usually between 6.5 to 7.5 hrs, the iPhone 4 is around 7 hours also. If your battery is not lasting that long you need to take it in to sprint and have them give you a new battery.
letshaveDEX said:
......I have yet to try the longer HTC method but it seems kind of pointless.....
Click to expand...
Click to collapse
HTC's method worked wonders for me. i'm a heavy heavy HEAVY user (no, not fat) and I get a good 10 hours with everything besides 4g on plus surfing, gaming and tethering for SEVERAL hours. For all that I do on my EVO 10 hours is HUGE. If I have a moderate day of usage (maybe a little more than moderate for the average user) I get around 19 hours.
Btw none of this will help if you are getting near 100% awake time. If that's the case you need to find the software causing that first.
Sent from my PC36100 using Tapatalk
Try this, it helped me. I did not come up with this btw.
With phone on, charge until green.
Unplug and turn phone completely off.
Charge phone until green once again.
Unplugand turn on. Once phone had turned completely on turn the phone back off again.
Charge until green one more time then unplug and turn on and you're done!
Sent from my Htc Evo 4g

[Q] CM7 battery charging % stuck

Hi guys,
I'd gladly post this on the CM7 RC's thread over at the dev forum but I have yet to accumulate 10 posts.
Lately I've been experiencing weird battery % issues in CM7RC2 and now CM7RC4, that the charging would be stuck at a certain percentage even if I charged it overnight. It never goes to full, until I pulled the battery and rebooted.
Is something wrong with my battery?
Thanks in advanced!
Are you using an official battery or a third-party battery?
I'm using the official one
I'd try charging the battery to full then wiping battery stats from within Clockwork Recovery.
drumist said:
I'd try charging the battery to full then wiping battery stats from within Clockwork Recovery.
Click to expand...
Click to collapse
I would definitely try this.. I had the same problem and it worked for me.. after you reset the stats, drain the battery again till the phone dies, fully charge again, and wipe again
Sent from my Liberty using XDA App
TNPaparazzi said:
I would definitely try this.. I had the same problem and it worked for me.. after you reset the stats, drain the battery again till the phone dies, fully charge again, and wipe again
Click to expand...
Click to collapse
First, doing the battery drain is effective in calibrating the battery meter but is still probably a bad idea because by doing it you are decreasing how much charge the battery can hold (i.e., a full charge will not last as long). It might not be super noticeable, and doing it once in a blue moon is likely not a big deal, but don't do it often or you'll just end up having to replace your battery. Deleting battery stats should be enough to correct the OP's problem, and allowing your phone to recalibrate under normal use is fine but takes longer.
That said, I do the battery drain anyway, but I would definitely suggest not doing it more than once every 6+ months. Wiping battery stats often is not necessary at all, unless of course you are actually having a problem like the OP is.
Second, you definitely should not clear battery stats AFTER performing a battery drain and recharge. The whole point of doing the battery drain is to let the phone gather new information about the battery since you just wiped the battery stats. If you wipe them again after doing that, the battery drain was useless.

Phone won't charge past 95%

OK so I'm having a issue with the 2.3.4 rom I'm on the latest cherry blurr on the stock radio also stock kernel and my phone won't charge past 95% I'm using transfer recovery to install the rom and also I use fastboot to wipe the phone before any rom install, can anyone tell me why im having this issue and I have wiped battery stats before
Sent from my MB860 using Tapatalk
You have to keep it charging even at 95.it does take some time to charge beyond 95%.
When it hits 95% the charging status shows the phone is unplugged but the phone is plugged in
Sent from my MB860 using Tapatalk
Did you try running CWM and resetting your battery stats? Do that once you've reached 95. Then let it drain completely. Then charge it to F. Then reset the battery stats again. I did that when mine wouldn't go beyond 99.
My ATRIX does the same thing, just leave it in until it reaches 100%. it will take a little while but it'll work.
rdubyah said:
My ATRIX does the same thing, just leave it in until it reaches 100%. it will take a little while but it'll work.
Click to expand...
Click to collapse
I've left mine on overnight and it stops at 98.. gonna drain and recalibrate
Sent from my MB860 using XDA App
Mine gets All the way to where it says phone fully charged. But as soon as I unplug it, it says 99%. Did a battery wipe then giving to let drain and recharge and will, wipe battery status again. Will report back.
Sent from my MB860 using XDA App
The phone will charge upto 100% and then stop till it hits around 95% again(not exactly 95% but example). This is a safety feature to protect the battery from charging continuesly.
Alright ill let it charge some more now and report back
Sent from my MB860 using Tapatalk
phro321 said:
Mine gets All the way to where it says phone fully charged. But as soon as I unplug it, it says 99%. Did a battery wipe then giving to let drain and recharge and will, wipe battery status again. Will report back.
Sent from my MB860 using XDA App
Click to expand...
Click to collapse
let us know how you get on as i have the same exact problem
Wiped and recalibrated and it's still the same. The second i unplug it goes down to 99 and pretty much downhill for the rest of the day
I think there is a general issue with the battery and GB and i don't think there is a concrete fix yet.
Thanks guys phone charged to 100% gave it some extra time
Sent from my MB860 using Tapatalk
If this happens, there is no need to drain the battery.
Boot into CWM and clear the battery stats.
Download Battery Calibration from the Market.
Start Battery Calibration, (and leave running).
Put your phone on charge with the AC charger. The phone will take a while to get to 100%, especially the last couple %.
You will hear a chime when the battery is fully charged. Leave charging for another 15 minutes, (sometimes if you unplug it right after it hits 100% it drops to 99% straight away).
Calibrate with Battery Calibration.
Enjoy.
Thanks for the tip!
Mine's been stopping at 98. It gets to 95 at a normal pace that I'm used to seeing with this phone, then takes probably 8-10 hours to get up to 98 and then just stops there and won't charge any more, no matter how long I leave it in. The OP said he just gave his extra time and it eventually got back up to 100...but how much extra time should I be giving it? No amount of calibration has helped me yet.
Any thoughts?
what I have done is when the phone is close to charged but not fully is to wipe the battery cache, then connect it to charge. for the first few charges it will stay at 100% for some time before it starts to drop, an it will drop faster then it should and be out of power before it hits 1% but on the 3rd charge it always seems to calibrate itself. I do not drain it fully just till it is pretty low. To put in hard number fully charged it is about 4200mV and so I wipe the battery stats close to 4150 and charge when it gets around 3700
do this a few times and for me at least the battery seem to be pretty well calibrated.
thebeardedchild said:
Mine's been stopping at 98. It gets to 95 at a normal pace that I'm used to seeing with this phone, then takes probably 8-10 hours to get up to 98 and then just stops there and won't charge any more, no matter how long I leave it in. The OP said he just gave his extra time and it eventually got back up to 100...but how much extra time should I be giving it? No amount of calibration has helped me yet.
Any thoughts?
Click to expand...
Click to collapse
Have you tried what I suggested in post #12?
Tao_Man said:
what I have done is when the phone is close to charged but not fully is to wipe the battery cache, then connect it to charge. for the first few charges it will stay at 100% for some time before it starts to drop, an it will drop faster then it should and be out of power before it hits 1% but on the 3rd charge it always seems to calibrate itself. I do not drain it fully just till it is pretty low. To put in hard number fully charged it is about 4200mV and so I wipe the battery stats close to 4150 and charge when it gets around 3700
do this a few times and for me at least the battery seem to be pretty well calibrated.
Click to expand...
Click to collapse
Phon shouldn't be going all the way to 1% I believe. Battery internal safety should shut it off at around 5% to prevent a complete drain which will ruin the battery. If you are seeing 1%, that would lead me to think you are not calibrated properly.
CaelanT said:
Have you tried what I suggested in post #12?
Click to expand...
Click to collapse
More or less.. for one, though, the battery calibration app should be doing the same thing as wiping the stats in cwm. And even still, my battery will never get to 100 no matter what, so I can't really wait til then to calibrate.. I've tried forcing earlier calibrations but to no avail
Sent from my MB860 using XDA Premium App
Try charging with the phone off overnight, turning it on while still charging then calibrate. Hope this helps.
Sent from my MB860 using Tapatalk
BBock9 said:
Try charging with the phone off overnight, turning it on while still charging then calibrate. Hope this helps.
Sent from my MB860 using Tapatalk
Click to expand...
Click to collapse
Thanks, I'll try doing that. I think I'm gonna let it discharge almost all the way, then turn off and charge while that little battery icon is the only thing on the screen. I'll try wiping again at the end, and let you guys know.

[GUIDE] Preserving Battery Life

This is particularly true for those who are un-rooted and on Stock where wiping battery stats is not available.
I bought my N4 on 1st of Feb, and the first two charge cycles, when the phone powered off due to the OS reporting the battery at 0%, I was unable to power it back on. This is great, as the phone battery is truly empty!
Some charge cycles later, my phone would power off due to the OS reporting 0% - however, I would feel as though the battery didn't last as long as I was used to.
So to make sure the battery is truly dead... I boot into fastboot mode by pressing Volume Down and Power on straight after it shut itself down. The phone stayed on for a further 27mins, bearing in mind that in this mode, the screen is on full brightness and always on. 27mins of screen on time for a phone that manages only about 4hrs of screen on time at best, is a considerable amount of left over juice in the battery that the OS is missing out on.
Normally to correct this, we charge up to 100% and wipe battery stats in CWM.
[GUIDE]
I have found that to leave the phone on in fastboot mode until it drains the battery out completely, plug in your charger, then boot into Android, would show the battery at 0% - this is a TRUE 0%... charge it all the way up to 100% and you should have back your full battery performance. Don't forget to allow the 99% - 100% time. This is very important - It will make it to 100% eventually, be patient.
This is all based on my assumptions/guestimates/theory - please do comment and correct if you are the wiser. [though for now, it works flawlessly]
OT - This does highlight a flaw in the OS however, it's a problem with all Android devices, will they ever fix it?
You're just calibrating the battery. I'm sure most of us already let it die without needing t enter fast boot.
Sent from my Nexus 4 using Tapatalk 2
scream4cheese said:
You're just calibrating the battery. I'm sure most of us already let it die without needing t enter fast boot.
Sent from my Nexus 4 using Tapatalk 2
Click to expand...
Click to collapse
Also, you should not drain it to such an extent. If a battery ever reaches true zero, it won't turn on again or charge. The phone turns off (says zero) around an actual 5% because they don't want you to destroy your battery
Sent from my Nexus 4 using xda premium
Censura_Umbra said:
Also, you should not drain it to such an extent. If a battery ever reaches true zero, it won't turn on again or charge. The phone turns off (says zero) around an actual 5% because they don't want you to destroy your battery
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
Exactly.
Sent from my Nexus 4 using Tapatalk 2
Censura_Umbra said:
Also, you should not drain it to such an extent. If a battery ever reaches true zero, it won't turn on again or charge. The phone turns off (says zero) around an actual 5% because they don't want you to destroy your battery
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
These are Li-Po batteries
scream4cheese said:
You're just calibrating the battery. I'm sure most of us already let it die without needing t enter fast boot.
Sent from my Nexus 4 using Tapatalk 2
Click to expand...
Click to collapse
I guess I wasnt clear or there was a misunderstanding... I let it die, reaches 0% and starts to power off, I then boot it into fast boot mode, and find the battery with at least another 30mins of screen on time. This extra battery is what I'm trying to calibrate back into the OS stats.
Censura_Umbra said:
Also, you should not drain it to such an extent. If a battery ever reaches true zero, it won't turn on again or charge. The phone turns off (says zero) around an actual 5% because they don't want you to destroy your battery
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
Good observation, always worthwhile hearing other opinions. I would say though, that 30mins of screen on time would be more than 5%.
I'm in my experience, the phone was fully dead after leaving it on in fastboot mode, battery all out. Then I plugged it into the charger, I got a flashing red light, and then the battery charge icon appeared. I then booted up and the OS reported a true 0%. This charge cycle, since I did this I'm at 28hrs with 20% to go with everything on [Wifi etc]
But so far, it's been a great way to get the most out of the battery.... lets get some more opinions, good or bad..
All thoughts welcome!
The flaw in this argument is that wiping battery stats in recovery does absolutely nothing.
Sent from my Nexus 4 using Tapatalk 2
joshnichols189 said:
The flaw in this argument is that wiping battery stats in recovery does absolutely nothing.
Sent from my Nexus 4 using Tapatalk 2
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If that really is the case, then surely that makes this approach even more convincing as something that "works" in maintaining good battery life!
Vyker said:
I guess I wasnt clear or there was a misunderstanding... I let it die, reaches 0% and starts to power off, I then boot it into fast boot mode, and find the battery with at least another 30mins of screen on time. This extra battery is what I'm trying to calibrate back into the OS stats.
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You can't drain the battery fully when its on because the device has protection against draining the battery to a point which will damage it. In fast boot this control is not in place.
Is this worth doing? No. Our battery aren't replaceable and shortening its life to gain 5% is not worth it.
jhericurls said:
You can't drain the battery fully when its on because the device has protection against draining the battery to a point which will damage it. In fast boot this control is not in place.
Is this worth doing? No. Our battery aren't replaceable and shortening its life to gain 5% is not worth it.
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I understand, good point, however we're not talking about just 5% here!
Explain how I was able to get an additional 30 mins screen on time!
Sent from my Nexus 4 using xda app-developers app
As skeptical as we can be, a lot of things can affect battery life so the extra 30mins could come from a number of factors.
On another note, I usually get 4-5 hours of screen time on my nexus 4.
Sent from my Nexus 4 using Tapatalk 2
Vyker said:
Explain how I was able to get an additional 30 mins screen on time!
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Click to collapse
Because it takes much less battery on fastboot mode? Radios don't need to be on , brightness is minimal, only 1 CPU runs at lowest frequency, flash memory is not powered on?
To have a logical argument here, we must know how long fully charged battery lasts under fastboot.
And in agreement with many other voices, I don't think draining battery obove manufacturer threshold is a brilliant idea.
Sent from my Nexus 4 in a Faraday cage

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