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With the HD2's pretty short battery life compared to my previous HTC phones, and also as I was a bit bored , I decided to have a look at how much the different systems drain in the HD2, and did some tests.
So for anyone interested, here are the results:
Base consumptions: (pick the one that suits your situation)
Standby, phone on, WIFI+BT off, no connections active: 5mA
Processor running idle, screen off, connections as above: 55mA
100% CPU usage (Coreplayer benchmark), connections as above: 315mA
USB connected, connections as above: 125mA
Additions: (add this to the base one depending on what you have on)
Connections:
BT on, idle: +1mA
Wifi on, idle: +5mA BUT!! If you enable wifi during standby (with BsB Tweaks or the WifiNoStandby CAB), the processor does NOT go to standby
anymore, so the base needs to be the 55mA above!
Connected to EDGE, idle: not measureable
Connected to 3G, idle: +4mA
Beware those 2 will occasionally and unpredictably send data every now and then, so this doesn't necessarily mean much.
BT transfer (file copy through ActiveSync, 120kB/s, CPU usage ~2%): +80mA
Wifi transfer (file copy with Wifi Remote access, 1MB/s, CPU usage ~3%): +200mA
EDGE/3G transfer: Pretty impossible to measure due to so many variables, but can be extreme (total current consumptions of 850-1150mA, so very approximative 500-800mA draw from the data connection during page loads are common!), and leads to most of the energy draw when using the net a lot. EDGE uses more power than 3G, consumption is higher when network coverage is lower, bad network throughput or congestion also mean lots of retries/overhead and less effective data transfer, using power for a longer time until the data is finally there.
Memory access (large file transfer):
Internal read/write through ActiveSync (speeds 2.5 / 2.1 MB/s respectively): +20mA / +130mA
Card read/write through ActiveSync (speeds 3.2 / 2.7MB/s respectively): +25mA / +40mA
Card read/write in USB disk mode (speeds 7.5 / 5MB/s respectively): +40mA / +45mA
Backlight:
10%: +65mA
20%: +78mA
30%: +90mA
40%: +105mA
50%: +121mA
60%: +136mA
70%: +154mA
80%: +170mA
90%: +190mA
100%:+210mA
GPS:
+95mA
Flashlight (with HTC Flashlight):
Level 1: +32mA
Level 2 (same as camera flash on): +107mA
Level 3 (same as camera "bright flash during shot"): +530mA
And remember the battery capacity: 1230mAh
So with this you can calculate your battery life for various activities. For example:
- Playing a video with full backlight: Let's say the video is well encoded (30% CPU use, for example 720x400 1Mbps DivX), that's about 150mA base, + 210mA backlight = 360mA, resulting in about 3h20 battery life.
- Same at night with only 40% backlight: Life goes up to about 5h!
- Wifi during standby for an 8h night, or a program that somehow prevents the phone from entering standby: 60mA or 55mA respectively, draining about 40% of the battery during that time.
- GPS program, with 70% backlight: Let's assume 150mA for the processor as it has some work to do, 90mA for the GPS, 154mA for the backlight = 394mA, or 3 hours.
- Music through wired headphones, screen off: the 55mA base plus a little 5mA as MP3 decoding is nothing for the CPU = 60mA or 20h.
- Same with a BT headset, with about half the BT bandwidth: 60+40 = 100mA or 12h
etc.
Charging
[EDIT 14.04.10]
This is now a dedicated section as I did some more thorough charging tests.
So, as some of you might know, the HD2 has 2 charging "modes".
- One is USB, that is used if the phone is connected to a PC, or an unknown device. In this mode, the current the HD2 will draw from the port/charger is limited to approx. 470mA, to stay within the maximum of 500mA a USB port can supply.
- The other is "dedicated charger", which is recognised on the original HTC charger (and some others, it's becoming a standard for a "dedicated charging USB port") by shorting of the 2 data pins of the USB connector in the charger.
USB charge
Important to know, during USB charge, the phone will NOT go to sleep, as it's supposed to be connected to a PC, and be running either ActiveSync, Disk drive mode, or modem, and in all 3 cases would be expected not to shutdown. So not only the current supplied to the HD2 is low, but the phone draws some of it for itself, leaving very little for actual charge - so expect loooong charge times.
USB charge with screen on (backlight dimmed, 10%): 285mA
USB charge with screen off (standby): 345mA (which shows the processor still runs and draws the "base USB" current)
Dedicated charger
When used with a charger that has the 2 USB data pins shorted, such as the original charger, the HD2 will draw a current that is proportional to the voltage on the USB power lines. To measure this I have used the original supplied USB cable, a variable regulated power supply, USB socket (with data pins shorted), and 2 meters for voltage/current. Voltages are measured at the "PC" end of the USB cable, so not taking account of losses in the USB cable. Will talk more about this later on.
Current vs Voltage diagrams are attached. Charge current is proportional to voltage, linearly until it reaches the max charge current, approx 830mA. This was measured so that the only draw is charge. If the phone is turned on while at max charge current, it will draw extra, until it reaches about 980mA, and will then stop to respect the 1A rating of the stock charger.
Now, to the influence of USB cables. I initially had some trouble with inconsistant numbers, phone only drawing 670mA from the stock charger, i.e matching neither the ~350mA from USB, or ~830mA from stock charger in "normal" condition. Turns out that to make it more convenient on my workplace I was using an USB extension between charger and HD2 cable. It was a $2 extension I bought on Dealextreme. Removing it solved the problem... and after making those measurements I poked with it again. Turns out that at 1A current, the voltage drop in the extension (which by the way isn't longer than the HD2's USB cable) was 1.8V! Yep, nearly 2 Ohms for a 1.5m extension! Couldn't believe it.
I have a cheap Chinese microUSB cable that wasn't as bad,but still significantly more resistive than the stock one, hence me noting I used the stock cable for my tests. So, quality of the cables, extensions, adapters IS important! Note the phone correctly reaches full charge current a little bit under the 5V USB spec, so everything is well tuned.
Now, important to know, Most 3rd party chargers will not have the 2 USB data pins shorted, and will thus result in the same behavior as mentioned under USB charge, the processor will also be running continuously drawing the "base USB" current.
It is often possible to modify 3rd party chargers by opening them and shorting the pins, speeding up charge. The voltage/current curve behavior is actually helping there, because thanks to it if the charger is overloaded its voltage will most likely fall a bit, and the HD2 will thus draw less and find a nice balance point. This DOES NOT mean there's no possiblilty of damaging the charger, but all 3 I modified did well. One that was really weak resulted in not much more current being drawn after the mod than before (i.e voltage fell very low, approx. 4.4V), however the gain from not having the processor running like in USB mode still sped up charge a little.
Thank you, that is one useful chunk of comprehensive information
Could you please explain the exact measuring method for these tests?
40% backlight at night is a tough example tho, Lumos on my device is set to 10% for 0 sensor value, and only because I can't set it to lower than 10%... nice to know battery drain goes up twice from 10% to 60%!
Also, 100% is usually really necessary under direct sunlight, in a normal lit room probably 40% backlight is more than enough to watch a video... all in all, with your superinteresting info, the battery doesn't look like lasting "too short" now, but more or less "the right amount considering the battery capacity".
My iPaq 210 has a 2200mAh battery, just to make a comparison... that's why I could go for 8 hrs during some bus trips while watching tv series, and I just needed to swap battery and used a little of the second one.
What's your estimate of the drain caused by activating push email? I've recently been doing some rather crude experiments myself, and one provisional conclusion is that push email on a hotmail account uses a lot more battery than push email on an Exchange server.
Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?
Battery levels
I found that power consumption of the battery got even worse after I went to Rom 1.66.707.1. However, after a few days, I let it run all the way out, switched back on, it ran out after a few minutes. Then after an overnight charge I found the battery (on standby) only went down by about 10 -12 % in 24hrs. I'm hoping this performance will continue.
What did you use for the testing?
pa49 said:
Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?
Click to expand...
Click to collapse
That would be reasonable as reading from an external media will need energy to access its contents... still, once the app files have been loaded into the device's RAM, it shouldn't matter much
You could also test by comparing:
1) copy say 30mb from one location to another of the internal mem
2) copy from microsd to microsd
3) copy from mem to microsd
4) copy from microsd to mem
ephestione said:
Could you please explain the exact measuring method for these tests?
Click to expand...
Click to collapse
Simply using the built-in current sensor, getting the reads from AEBPlus battery information screen, and methodically turning things on/off once the others are evaluated and can be subtracted from the total reading.
ephestione said:
40% backlight at night is a tough example tho, Lumos on my device is set to 10% for 0 sensor value, and only because I can't set it to lower than 10%...
Click to expand...
Click to collapse
Really? You should force the backlight off then
I love bright images myself, so even in my bed in total darkness if I watch a video or photos I'll force 100% backlight I have Lumos set to force 100% for Coreplayer, Resco Photo manager and HTC album
Of course not for browsing or just messing around, in that case it's 20% for me
Shasarak said:
What's your estimate of the drain caused by activating push email? I've recently been doing some rather crude experiments myself, and one provisional conclusion is that push email on a hotmail account uses a lot more battery than push email on an Exchange server.
Click to expand...
Click to collapse
That's one thing I'd have no idea about... I've never used push email at all. And that's "standby usage", so hard to evaluate, as you never know when it kicks in.
Measuring that would need to be done on a long time. I'd say to leave your phone one night with push email off, one night with Exchange only, and one night with hotmail only, and then check the difference, preferably with a battery at about 80% charge at the start (mine seems to fall from 100% to 90% in a few minutes before becoming more regular, so I'd say the top of the scale isn't that reliable).
And I should really try push email once, that would be nice, but I *think* I have no provider that can do it for me... well I have a gmail account I never use, I should try to see if I can have it check my usual 3 mail accounts, aggregate and push... never really looked into that stuff.
pa49 said:
Excellent stuff, you are to be congratulated.
I have a long held theory and I wonder if you are in a position to to test it?
I believe that battery consumption is greatly increased when an app is run from mem card and would be intrigued to see a comparison between an install to this as opposed to phone mem.
Any chance?
Click to expand...
Click to collapse
Thanks
Well I'd tend to refute that theory, because when I tested the BT and Wifi in use I tried read from internal memory, write to internal, read from card and write to card, and all 4 were identical. I should have mentioned it indeed, but I was mostly interested to seeing if reads (wifi/BT "sending") and writes (wifi/BT "receiving") would have an influence on consumption, which wasn't the case, as well as whether the throughput was different, which wasn't the case either.
But I've done a few more tests, see the updated first post
One intersting thing is firstly that when the HD2 is connected to USB, the current draw grows significantly, so I've made a new "base consumption".
Next, the card is actually faster than the internal memory both in reads and in writes, tested both through activesync for consistency. Writing to the internal memory eats a LOT more than writing to the card. Reading from the card eats a little more than reading from internal memory, probably evens out as the reads are shorter due to faster transfer rate.
I've added some charging tests as well. Apparently, even if the phone "disconnects" from USB when turned off, the processor still runs and uses about the "USB connected" base current.
kilrah said:
Simply using the built-in current sensor, getting the reads from AEBPlus battery information screen, and methodically turning things on/off once the others are evaluated and can be subtracted from the total reading.
Click to expand...
Click to collapse
d'oh aebplus has a battery information screen, checking it right away In that case you'd have to take into consideration aebplus' current absorption anyway... which is not measurable as you cannot check the current intake of aebplus without aebplus being running
I have the cab on the sd already, but didn't install if after noticing that didn't work for button assignments with later versions of the rom... does it work for you on that side? I used the program all the time on my previous ipaq because it was oh so useful but never got around to notice it had a battery info subsection.
Really? You should force the backlight off then
Click to expand...
Click to collapse
Wouldn't have much sense doing it in the dark would it (admitting it's possible altogether on the HD2!)
But I actually used my oooold casio cassiopeia, about 7 years ago, with backlight turned off, while reading ebooks with speed reader plus during train trips, as the neon lights created a reflection good enough on the display so that I didn't need backlight...
in the end, the backlight died altogether and until I bought a new device, I managed to use it with light turned off
A flashing LED (incoming SMS warning, e.g.) seems to add consumption of 1-3mA.
Running FlexMail in background with a push service (IMAP IDLE) adds up to 30mA.
ephestione said:
does it work for you on that side?
Click to expand...
Click to collapse
AEBPlus works fine for me yes... but I don't have a "latest version" ROM AFAIK. I don't like WM6.5.x new softkey arrangement, so I'm staying with 6.5.
Anyway more about Push, I configured that through gmail yesterday, and it works just fine. I left it on during the night, and this morning I had lost 8% battery. So it's pretty much negligible. I received 2 e-mails during the night and was on 3G network.
this is a nice topic! i am interested in how much extra it uses when you are playing a MP3 with the build in HTC app?
maybe it would be a nice idea to make a program that outputs results like you pasted fast and easy (something like a benchmark app) so we can test different rom's fast? too bad i cant write anything otherwise i would try..
OK, seems MP3 uses 120mA screen off, both with Sense player and Coreplayer, so:
Processor running idle, screen off base + 65mA
But it seems to make some pretty big "jumps" once in a while. Maybe they both decode ior fetch from memory by "batches"...
my test,
HD2 rom 1.66
with BT on and BT off (configured but no connection to headset) difference in consumption is 60mA .!
BT is draining my HD2 .!
kilrah said:
OK, seems MP3 uses 120mA screen off, both with Sense player and Coreplayer, so:
Processor running idle, screen off base + 65mA
But it seems to make some pretty big "jumps" once in a while. Maybe they both decode ior fetch from memory by "batches"...
Click to expand...
Click to collapse
OK, I can't confirm the BT issue. Did you observe over a long period of time? The "quiet" current for MP3 I seem to get is 185mA with screen on and backlight at 10%, but sometimes it will climb to 280-320mA for a moment and go down again, both with BT on and off. With screen off for a while it seems to stabilise at the "quiet" level.
BTW, it seems that Advanced task manager isn't reporting CPU usage levels properly. Does someone know of a CPU monitor that works correclty on the HD2?
Yup. review over multiple 6 mins. all baseline(3g/brightness) setting the same. resetting each time for off on BT.
kilrah said:
OK, I can't confirm the BT issue. Did you observe over a long period of time? The "quiet" current for MP3 I seem to get is 185mA with screen on and backlight at 10%, but sometimes it will climb to 280-320mA for a moment and go down again, both with BT on and off. With screen off for a while it seems to stabilise at the "quiet" level.
BTW, it seems that Advanced task manager isn't reporting CPU usage levels properly. Does someone know of a CPU monitor that works correclty on the HD2?
Click to expand...
Click to collapse
Another consideration:
Data connection sucks power when used actively. Badly. As mentioned in the OP I haven't made comprehensive tests due to low monthly allowance, but I've had a look during normal use.
I'm pretty regularly doing 1hr train rides, during which I will be listnening to music , and browse the net at the same time. It's usually bright, so backlight will probably be at 70%. Signal is relatively low most of the time, on EDGE, inbetween small towns. When I'm on a "static" page (reading an already loaded page), current drain varies between 250 and 350mA.
But while loading a page, it will easily soar to 800mA+. Considering it takes 30-60 seconds to read a page, 20 to load a new one, and repeat... you can quickly see that this kind of usage leads to serious drain... in less than 2 hours the battery would be dead.
So be aware of how much power data connection will use. It's directly proportional to the amount of transferred data, and the worse the reception the more power it uses.
I should try using opera mini again, like I was always doing on my Kaiser. I never noticed excessive drain with it, but opera mini easily divides traffic by a factor of 10...
Just wanted to report that the new version of the superuseful BattClock has now a builtin battery current output, even if it's not really update once per second... seems more like one every 10 seconds.
I get ~240mA playing fullscreen stretched Frasier in lowest backlight (but that's with the keypad leds turned on all the time, I don't know why they don't go off, and I don't have keypadledcontrol installed... so that's a problem), and I get a total 630mA with HTC flashlight at maximum.
Good news! Bye bye Batti
Normal about the refresh time, the sensor only updates every 20 secs or so.
Some new considerations I posted somewhere else but should have put here.
After some time the HD2 seems to have better battery life, but usually it's not your battery lasting longer, it's just you not spending your day playing with the thing anymore.
It's always the same thing, the more a device can do, the more you do with it. On my first 1h train journeys after getting my HD2, I was able to kill 50% battery in 1hr. My first thought was "wow, with my Kaiser I would only use like 15%!!"
But then I took a second thought. I used 50%, but I was browsing the web, in bad reception areas, while listening to music the whole time. With my Kaiser, I'd put music on, check 3 webpages, then put it on the tray with just MSN connected and just pick it up to read/type a message once in a while.
On a next trip, I "forced myself" to do the same with the HD2. Just checked the news for 5 mins, then only listened to music and picked up msn once in a while, plus an unexpected 10min phone call. Guess what? I've only used 20% battery during the trip this time
The "problem" is that browsing with the Kaiser was just painful, so I'd just check the news and put it away. On the HD2 it's so comfortable I forget it and just spend my whole trip browsing heavy pages, which obviously kills battery in no time...
exactly my thoughts and findings
I've noticed it previously during usage (like on the internet while having MSN running, or while playing games)
but I just got off a phone call which lasted about 20 minutes, and the front (and back) of my phone was just too warm for me to ignore. I would have suggested that it was the heat from my cheek against the phone but that wouldn't explain how the phone was quite noticeably warmer than my cheek.
The backlight wasn't on (i doubt the LED backlight would cause much heat anyway).
Does the mega have any internal temperature sensors like PC's have? And any software to read them?
My previous phones NEVER got this hot on even hour long calls,
and mix this with the fact that at my work one of the PDA's blew up a few weeks ago (was the battery), it just makes me that more paranoid!
I am going to Hard Reset soon anyway as things started running a little slowly recently, I hope it will also stop any hidden processes that may be running in the background and overworking the cpu. But I would still like to know of any software
Weznezz said:
I've noticed it previously during usage (like on the internet while having MSN running, or while playing games)
but I just got off a phone call which lasted about 20 minutes, and the front (and back) of my phone was just too warm for me to ignore. I would have suggested that it was the heat ..../QUOTE]
I think its pretty normal to heat up during long conversation. Their manual also says "Using any function for long time will heat up the phone", but only upto a level.
Click to expand...
Click to collapse
i've never experienced warming of the phone which is coused by operating it , well maybe just a lil utube watching for an hour but it was warm of my hands , i'm only worried when i leave it charging and after 15-20 mins LOL ! the phone is HOT i know that is normal , just sharing opinion
Heat comes from 2 sources in general external and internal.
External is from sun, your hands or phone in your pocket. On longer run this is not good for battery life.
Using navigation in your car during summer can run your phone real hot and feels quite uncomfortable! From a 20 min call it should not. But this is subjective.
Internal heat is caused when your processor has to work hard; like when several programs running and processes in back ground. You can check and kill them with task manager (FDC soft task manager) and batteryguard. Also soft reset kills most "unwanted" processes. A good indication for high level of processor activity is when your battery level goes quickly down.
Its normal mate, on mine when i use GPS for long time it does the same, processor works hard and battery gets hot.
Not sure if navigation alone causes your battery to run hot. Since navigation can run on 200Mhz processors and Mega processor has much higher clock speed it is overspecified.
The influence of phone close to windscreen and therefor impact of light/sun may be much bigger. When I run navigation (TomTom) in winter phone stays nicely "cool".
Not sure if it could help but once i noticed the Mega too warm and discharging instead of charging, after i connected it to the notebook via usb cable!
Rebooted PC and HTC and everything luckly returned normal...
gfreeman86 said:
Not sure if it could help but once i noticed the Mega too warm and discharging instead of charging, after i connected it to the notebook via usb cable!
Rebooted PC and HTC and everything luckly returned normal...
Click to expand...
Click to collapse
Indeed a soft reset in most cases solves this.
Thought the title would get your attention.
After upgrading to Froyo, I have many issues, two of which I'll cover here in hope that someone can resolve them.
First issue is battery life. Absolutely horrible after upgrading. Thought it would be the opposite. Can someone please provide some resolution to this issue? I've disabled a number of things said to resolve this problem but none have worked.
The second issue is the accelerometer after upgrading. Most screens end up in landscape view and switching back to portrait is difficult. I have tried to calibrate it but that didn't work. Don't like the huge delay or failed attempt to switch between both on this version. Calibration does not work.
Any help is appreciated...
pookieguy said:
Thought the title would get your attention.
After upgrading to Froyo, I have many issues, two of which I'll cover here in hope that someone can resolve them.
First issue is battery life. Absolutely horrible after upgrading. Thought it would be the opposite. Can someone please provide some resolution to this issue? I've disabled a number of things said to resolve this problem but none have worked.
The second issue is the accelerometer after upgrading. Most screens end up in landscape view and switching back to portrait is difficult. I have tried to calibrate it but that didn't work. Don't like the huge delay or failed attempt to switch between both on this version. Calibration does not work.
Any help is appreciated...
Click to expand...
Click to collapse
buy a new battery and a good charger
menu>settings> display> uncheck Auto-rotate screen
screen
Why would I want to uncheck that option? I want it to auto rotate but want it to happen quicker than it has after upgrading.
battery..
In addition, the battery is obviously not the problem here. This started after upgrading to Froyo.
Were you using a custom ROM with 2.1?
Are you using a custom ROM with 2.2?
As far as I know, the stock ROM with 2.1 didn't have great battery life either (thought I'm not sure, I rooted my phone the day I got it ). So if you're using a stock ROM with 2.2, you could have the same issue.
Also, if you are rooted, try using SetCPU. Even with the default kernel you can use it to underclock your phone when the screen's off and save a lot of battery.
pookieguy said:
Thought the title would get your attention.
After upgrading to Froyo, I have many issues, two of which I'll cover here in hope that someone can resolve them.
First issue is battery life. Absolutely horrible after upgrading. Thought it would be the opposite. Can someone please provide some resolution to this issue? I've disabled a number of things said to resolve this problem but none have worked.
The second issue is the accelerometer after upgrading. Most screens end up in landscape view and switching back to portrait is difficult. I have tried to calibrate it but that didn't work. Don't like the huge delay or failed attempt to switch between both on this version. Calibration does not work.
Any help is appreciated...
Click to expand...
Click to collapse
You hate Froyo then please return your EVO to sprint
are you running a task killer? try removing it. Have you tried any of the MANY battery life tricks? Try flashing the update.zip, could have been a messy install. you also could be suffering from useritis.
root
Thanks for the reply. No, phone has not been rooted. I simply waited for the 2.2 upgrade and can confirm both issues are a result of upgrading. You are right...the stock ROM did not have good battery life. However, after upgrading, it is much worse in comparison.
The g-sensor issue is also a huge problem. With that said, I'm looking for a fix to these two issues.
Thanks,
task killer..
tonyh703,
Yes, I'm running Advanced Task Killer which did not have a problem before. Is this an app that can cause this problem? I'll remove it if so...
You really need to do a little detective work to find out why your battery is not lasting. My battery is actually lasting noticeably longer on froyo. I was using Fresh 1.0.1 before with Netarchy's kernel and would just barely make it through the day of moderate use. Now that I have updated to Fresh 3.1.0.1, I am easily making it through the day with about the same use. Yesterday, I went 14 hours and still had 26% left when I plugged it in for the night. My usage was about 2 hours streaming last.fm, about a half hour of phone calls, about 1 1/2 hours of internet and twitter, about 45 minutes watching video's, and an hour and a half of reading with my kindle ap. To me that is pretty darn good. I have gps on, twitter syncing every half hour, and google sync on, most of my other stuff like email and such is set to manually sync. The only thing I did notice is that the first day after going to Froyo, my battery went down pretty quick, but after a day or two it settled down to the way it is now on it's own. Today I have had about the same use as yesterday so far, and have been off of the charger for 11 hours and have 76% remaining.
As to your other problem, can't say, mine is working fine.
If youve got an led flashlight type of app installed uninstall it they conflict with the HTC LED flashlight. That seems to be the most common problem with people upgrading to Froyo.
Agree on your second point. I wish there was a way to at least lock the screen to an orientation when need. The delay though is ridiculous.
I have also noticed that the delay to type sometimes is severely long causing me to retype the words a second time before they appear in the screen.
Sent from my PC36100 using XDA App
FWIW - I found a little trick on a forum somewhere that allegedly came from HTC techs...
It goes like this - first, charge your phone as normal (phone on, 8 hours)
Then, after 8 hours and the phone reporting fully charged status, take the phone off the charger for about 3 minutes (just enough to slightly discharge it) and then turn it off (power down) and put it back on the charger for an hour or so.
Then, take it off the charger and turn it back on.
That's it! It sounds a bit ridiculous, but I think the cited reason was that whenever you install a new ROM, the "system" needs to understand when the battery is truly full and this trick helps to recalibrate and ensure that it is.
I really don't have any way (nor the desire) to verify the science behind this, but I did it myself after the horrible battery life I got with FroYo.
About a week out now and my battery is behaving completely normally, and possibly better than with 2.1, though only marginally if that...
Give it a shot - if it works, there you go, if not... Well it's not like you've lost anything.
Good luck, though YMMV.
Sent from my EVO 4G (Froyo - Stock HTC Rom)
have any of yall had a long delay when putting in a name for the reciver in sms? I kid you not it takes almost 3 to 5 sec for it to pull up a name and phone number from my phone book.
Its sad that you need to do "tricks" to get decent battery life, because most people expect it out of the box. Yes you can apply a custom rom with a undervolted cpu, but that shouldnt be necessary. I personally love doing all that stuff, but the majority of people are completely ignorant to these methods and might return their phones because of battery life, but for you people on here...BAKEDSNACK 1.2.5 with the latest of his kernel..amazing battery life.
Get rid of that task killer!! Froyo does not need it... Not to mention none of the task killers support Froyo correctly. Uninstall it, try using Froyo without it.
I recommend getting rid of the task killer and go without system panel lite. It works with froyo without any problems. I also recommend letting your battery completely die out before charging it again.
My Evo worked without any issues after the update to froyo. Also, if you are a widget fanatic, I recommend limiting the amount yo u use . The reason being that everytime you unlock your phone and scroll from one page to through next, you are loading said widgets into memory which help to eating up the battery quicker.
Also if you have a lot of things updating in the background, that can kill your battery quicker. I'm always on my phone and get anywhere from ten to fourteen hours of use. I also use a cpu manager to extend the life of my battery when not in use.
Sent from my HTC Evo
DO NOT DEPLETE YOUR BATTERY COMPLETELY!! These are Li-ion batteries. Depleting the battery too much can damage the cells. Discharging the batteries 100% before charging to avoid memory effect is a phenomena unique to Ni-Cad batteries. If a Li-ion is discharged too severely, it causes an irreversible reaction inside the cell that prevents the battery from holding any charge at all. This common in laptop batteries.
To the OPs issue, do you have the latest Facebook update (1.3.1)? Version 1.3.0 had an issue that was keeping the phone awake eating up battery life.
Sent from my PC36100 using XDA App
sombdy said:
DO NOT DEPLETE YOUR BATTERY COMPLETELY!! These are Li-ion batteries. Depleting the battery too much can damage the cells. Discharging the batteries 100% before charging to avoid memory effect is a phenomena unique to Ni-Cad batteries. If a Li-ion is discharged too severely, it causes an irreversible reaction inside the cell that prevents the battery from holding any charge at all. This common in laptop batteries.
To the OPs issue, do you have the latest Facebook update (1.3.1)? Version 1.3.0 had an issue that was keeping the phone awake eating up battery life.
Sent from my PC36100 using XDA App
Click to expand...
Click to collapse
I could see how this could be bad if you discharged it completely every single time, but every phone ive had including the iphone, it has been specificly stated many times to COMPLETELY DISCHARGE THE BATTERY ATLEAST ONCE A MONTH
Still no luck...
Guys,
I have removed the task killer and have removed the other LED Light utility. Still having battery issues. Any other suggestions please??
Also,
What about the accelerometer? Having many issues with it. First off, when a text msg comes in, it automatically shows in landscape. Phone switches to landscape fine but it is very difficult to switch back to portrait.
Any other help is greatly appreciated.
Thanks,
My test & results regarding the 60mA standby high battery drain in Android -PLS READ
Hi all. This is a continuation to the thread here but as that thread is full of theories and speculation I figure I'd start a new thread with 'real world' results when it comes to this battery drain issue in Android.
I've been trying hard this weekend to replicate that's been causing the seemingly spontaneous leaps to high battery drain in standby.
I can confirm, at least on my end (UK HD2, WM6.5 CleanEx, Android Darkstone SuperRAM 1.5) that enabling airplane mode in WM before booting android DOES NOT stop the high battery drain.
It seems, at least right now, that the battery drain in indeed caused by the GPS module either being or having been active in Android.
This morning I was having regular 5-9mA drain in standby. I enabled GPS on the way to work, took the phone off the charger and BAM... 60mA in standby thereafter (long after closing all GPS-enabled apps).
Rather than rebooting or anything like that, I plain disabled the GPS module via the Power Control widget (you can add it to part of your homescreen). Switched backlight off and on again a few seconds later... 5-9mA drain (and this is with WiFi enabled)
Here's a test I've just done.
Conditions:
- Loaded DarkStone's Froyo SuperRAM 1.5.
- WiFi, Data, Sync, Auto-brightness, 3G+2G enabled. Bluetooth isn't enabled.
- I won't be rebooting, using task managers or anything like that in between tests as I want to find a 'practical' solution to this issue until a fix is found. Rebooting, waiting for a GPS lock, etc every time you wish to put your phone in your pocket isn't practical.
- If I report ~5mA this is just what's being said by CurrentWidget. It may spike a few seconds later but we can, I think, safely assume that there is a major difference between ~5-30mA readings and ~59-90mA readings.
Results:
1. ~5mA to ~10mA in standby since disabling GPS in Power Controls.
2. Enabled GPS control again and we're up to ~59mA to ~90mA in standby.
3. Kept GPS control enabled but disabled "Use wireless networks" in Data and Security - ~59mA in standby (NOTHING LOWER!).
4. Disabled GPS from Power Control widget again and we're back down to ~9mA
5. Kept GPS disabled but enabled "Use wireless networks" in Data and Security, then opened Google Maps to get my location based on cell tower. Switched screen off. ~10mA in standby.
6. Enabled GPS again - ~60mA in standby
7. Disabled GPS again - ~9mA
Conclusion:
There seems to be a serious problem with the GPS module/driver/whatever under Android when it comes to power management!
SO - it seems, at least for me, that the only solution to this issue right now is to disable GPS altogether and renable it when I want to use a GPS-based application. This isn't great as these wonderful devices are heavily built around being able to keep track of your and friends locations, movements and all other GPS-orientated tasks.
So +1 for an urgent call out to the devs to took further into this issue! Please everyone keep posting your results as this is the biggest, if not only, thing keeping me and I'm sure others from saying Android is perfect for the HD2!
On another note - I also find that the battery discharges when GPS is enabled (e.g. running Google Navigation or Sygic Aura) even whilst plugged in to my car's 12v port via USB adapter. This isn't *always* the case, but it ALWAYS can only 'trickle charge' at best... i.e. An hour on the road using GMaps/Aura will, at best, have around 7% put back into the battery. Under WM with TomTom active the phone would have charged/held its charge quickly. This makes using Android on the HD2 for long trips pointless.
Hope these results help weed out this issue that's been driving me and many others insane for a long time!!
I'd like to elaborate on my last point a little more. The stuff about the battery drain / lack of fast charge in the car with GPS enabled.
I disabled GPS and plugged the HD2 into my 12v, it charged pretty quick. As soon as I enabled GPS and ran for example Google Navigation it would either lose %s despite being plugged in or just *barely* charge after being plugged in for a while.
Remember I have no problem charging and holding charge in WM with GPS active. I had a similar problem with my HTC Hermes in-car years ago.
So this again points to the GPS chip or driver putting excessive strain on the battery, under Android.
Who else has been using Android for Navigation in their car and noticed this?
I will switch radios but I've been though probably half a dozen radios since Android came to the HD2 and experienced this problem with all of them!
SMS92 said:
I'd like to elaborate on my last point a little more. The stuff about the battery drain / lack of fast charge in the car with GPS enabled.
I disabled GPS and plugged the HD2 into my 12v, it charged pretty quick. As soon as I enabled GPS and ran for example Google Navigation it would either lose %s despite being plugged in or just *barely* charge after being plugged in for a while.
Remember I have no problem charging and holding charge in WM with GPS active. I had a similar problem with my HTC Hermes in-car years ago.
So this again points to the GPS chip or driver putting excessive strain on the battery, under Android.
Who else has been using Android for Navigation in their car and noticed this?
I will switch radios but I've been though probably half a dozen radios since Android came to the HD2 and experienced this problem with all of them!
Click to expand...
Click to collapse
check your hd2 if it is charging as USB (charge only) or as a regular charger. That happened to me when I used the wrong cable for the charger.
You should definitely try recalibrating your battery, and as jose mentioned, if you're using a charger\cable that isn't meant for your device it will slowly damage your battery.. so I would recalibrate and wipe batt stats. Also, using EBL set to 3 sec helps a lot and using SetCPU with correct profile settings.. the list goes on man, the quicker you boot from winmo to android the better. (switching to nand might be a good decision as well if your ready to lose WM.. huge difference)
There's quite a few battery threads now.. might want to take a peak
http://forum.xda-developers.com/showpost.php?p=9019755&postcount=29339
http://forum.xda-developers.com/showthread.php?t=734886
http://forum.xda-developers.com/showthread.php?p=8990839#post8990839
http://forum.xda-developers.com/showthread.php?p=10433749#post10433749
http://forum.xda-developers.com/showthread.php?t=881958
http://forum.xda-developers.com/showthread.php?t=827355
http://forum.xda-developers.com/showthread.php?t=819534
http://forum.xda-developers.com/showthread.php?t=825989
http://forum.xda-developers.com/showthread.php?t=796134
http://forum.xda-developers.com/showthread.php?t=749753
http://forum.xda-developers.com/showthread.php?t=737001
That should do it I think..
Scabes24 said:
... if you're using a charger\cable that isn't meant for your device it will slowly damage your battery..
Click to expand...
Click to collapse
Curious about this statement. What would define the wrong cable? Thickness? Aren't all micro usb connections the same?
My HD2, running Dutty FAM V24 ROM, SD card version android built 2.2.1 with Sense. I installed the current widgets which shows i have over 100 mA draining even when my phone is not used. Thank for your information disabling the GPS in Power Control Widget, I now have 6-8 mA during phone standby.
Looks like this make sense having the GPS disabling, compromising some features but having 2 OS in one phone is fairly acceptable. I can just switch back to WM6.5 when I need navigation.
I'm really frustrated because i really used to love the n7 so much I was an early adopter and bought another one after I dropped my first and then went on to buy my girlfriend one. But after being plagued with this issue and stuck on 4.1 its just not the same anymore since I cant flash custom roms all day :/
I've been having a charging issue with android 4.2.1 since it came out (both stock and all the roms I tried) but I noticed that whenever I reverted to 4.1.2 the issue went away completely. So I've been waiting for 4.2.2 to come out for a while now to see if it fixed the issue and after flashing the update tonight it seems to have the same problem.
I've tried searching for months now and haven't found any answers.
So this is the issue with both 4.2.1 and 4.2.2:
The battery charges at an insanely slow pace to the point that it ruins the tablet completely. I'll plug it in over night for 8+ hours and it will not gain more then 40% battery life in that time.
Its to the point that when I was just using it right now on the charger with brightness turned all the way down and nothing on other then sync and WiFi that light web browsing for 10 mins caused it to discharge a percent after being plugged in for 19 minutes.
Notes:
Its a c70 16gb
I tried 3 different stock N7 chargers with stock cables as well as trying them with other cables.
I'm not plugged into any kind of extension cords and I've tried multiple wall sockets at different locations.
My girlfriends nexus 7 32g charges fine on 4.2.1 and I have not updated her to 4.2.2 to test yet.
I haven't checked the battery connection because like I said whenever I revert to stock 4.1.2 or any 4.1.2 rom it charges in 4 hours flat or 6 hours with heavy usage while charging.
So anyone have any ideas? If not I guess I have to rma.
Do both, yours and your girlfriend's devices take that long to charge?
sl4y3r88 said:
Do both, yours and your girlfriend's devices take that long to charge?
Click to expand...
Click to collapse
Nope her nexus 7 charges fine. ( a little slower on 4.2 then 4.1 but nothing like mine)
Her nexus does have issues with turning on sometimes on 4.2.1 like a lot of other users but its nothing holding the power button for 10 seconds doesn't fix.
It also just noticed it seems to discharge at an extremely fast pace. (still on 4.2.2)
It just dropped from 55% to 51% in the time I've typed these responses with brightness all the way down.
So anyone want to try and help me figure this out before I send it in friday? I called it in to Google play device support to try and report the software bug and they said its the first they heard of it and they would pass it on but I felt like the rep didnt want to help as I bought it from a third party. I'm willing to do any tests suggested and hop between software versions to try and figure out this bug.
Why do you think it is a "software bug" when millions of people running the "same software" don't experience the same behavior?
I realize that software can exhibit data-dependent behaviors, and thus exhibit low occurrence rates... but there is no "software" involved in charging the battery.
Do you think a booted Linux kernel is needed to charge a battery? How would the battery get charged when the device is turned off in that case? C'mon!
Send it back and tell them the battery (or charge contoller CIRCUIT) is defective.
If it's out of warranty, PAY them to replace it.
bftb0 said:
Why do you think it is a "software bug" when millions of people running the "same software" don't experience the same behavior?
I realize that software can exhibit data-dependent behaviors, and thus exhibit low occurrence rates... but there is no "software" involved in charging the battery.
Do you think a booted Linux kernel is needed to charge a battery? How would the battery get charged when the device is turned off in that case? C'mon!
Send it back and tell them the battery (or charge contoller CIRCUIT) is defective.
If it's out of warranty, PAY them to replace it.
Click to expand...
Click to collapse
Then how do you explain that if right now I flash back to 4.1.2 it will work fine? If you want I'll provide screenshots.
I just flashed back to 4.1.2 this morning and it worked perfectly. Just now I flashed codefires 4.2.2 build and the problems back.
Please explain how that is hardware related.
I may of jumped the gun assuming it was a charging issue. It seems like it might be a battery drain issue. Here's a couple screenshots from a fresh install of codefirex 4.2.2 build.
Sent from my Nexus 7 using XDA Premium HD app
All I was trying to say is that when the OS is booted, at most all it does is monitor battery voltage and current - it doesn't get actively involved in control of charging circuitry.
At most this historical data can be used to *predict* when the battery will run out of juice, and this number is what is shown to the user as a % charge number. Hopefully that allows the prediction to be sort of correct as the battery ages and it's characteristics change.
This "calibration data" is only used for prediction - it does absolutely nothing to alter the rate at which current is drawn from the battery by the motherboard, nor for attempting to alter the behavior of a battery charge controller.
Li-Ion and Li-Polymer batteries are indeed complicated enough that they should not be charged by extremely simple circuits if a long operating lifetime is desired. For this purpose though, monolithic battery charge controllers chips are used - they do not need any assistance of a micro-controller or advanced CPU running a modern OS. That's why they are able to charge batteries rapidly and appropriately when the motherboard is in a "powered down" state.
Relative to a big multi-core CPU chip, which might have hundreds of millions of transistors, battery charge controllers are extremely small circuits - they are sold by the billions and cost in the ballpark of one to several pennies. They don't need the support of a CPU or even a microcontroller to operate correctly.
Good luck with your tab; I hope you enjoy it.
bftb0 said:
All I was trying to say is that when the OS is booted, at most all it does is monitor battery voltage and current - it doesn't get actively involved in control of charging circuitry.
At most this historical data can be used to *predict* when the battery will run out of juice, and this number is what is shown to the user as a % charge number. Hopefully that allows the prediction to be sort of correct as the battery ages and it's characteristics change.
This "calibration data" is only used for prediction - it does absolutely nothing to alter the rate at which current is drawn from the battery by the motherboard, nor for attempting to alter the behavior of a battery charge controller.
Li-Ion and Li-Polymer batteries are indeed complicated enough that they should not be charged by extremely simple circuits if a long operating lifetime is desired. For this purpose though, monolithic battery charge controllers chips are used - they do not need any assistance of a micro-controller or advanced CPU running a modern OS. That's why they are able to charge batteries rapidly and appropriately when the motherboard is in a "powered down" state.
Relative to a big multi-core CPU chip, which might have hundreds of millions of transistors, battery charge controllers are extremely small circuits - they are sold by the billions and cost in the ballpark of one to several pennies. They don't need the support of a CPU or even a microcontroller to operate correctly.
Good luck with your tab; I hope you enjoy it.
Click to expand...
Click to collapse
Thank you for taking the time to write out this detailed explanation. I read it over a couple times and that all makes a lot of sense and now I have a little better understanding of how things work charging wise.
But I still can't wrap my head around how the problem DISAPPEARS COMPLETELY on any 4.1 based build...
I'm not trying to contradict you in anyway it seems like you are way more knowledgeable then me on the subject.
It just doesn't make any sense and I was hoping you could make more of it for me.
Maybe it isn't the charging but a battery drain issue something on 4.2 based builds is draining more current then the charger can dish out.
But while i was doing research I read that chargers up the current they dish out if the device is in use. Is that correct?
I've looked into the media server bug but as I just did a fresh install of stock 4.2.1 and haven't changed or added anything to the file structure that wasn't included in the factory image, I also went through and turned off the keyboard press sound and all other sounds like explained in some of the threads I have read. I also read that the problem is supposed to be fixed in 4.2.2. I also haven't installed any apps from the market.
I guess all I'm looking for is the answer to this question:
Could there really be a hardware related problem of any sort (not just charging and battery problems but anything) that causes problems with 4.2 based builds specifically but doesn't cause problems with 4.1?
If the answer is yes then I don't have to feel bad about sending it in but if its software based issues I'll be upset that I wasn't able to fix it and gave up.
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
projectzro said:
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
Click to expand...
Click to collapse
I'll give this a try right now then post results, the battery is already pretty low so It shouldn't take very long. Thanks for the response.
projectzro said:
Have you let the battery drain all the way or do you just plug it in at a certain point? if not let it get to the point were it will turn itself off. if the battery with the cross in it stays for more than it would take for 1% to drain then it just might be your battery stats file. even if its not let it drain and then charge it while its off. you can check the battery by pushing the power button quick. i know i have had this problem with other devices that were fixed by doing this. and my N7 did it last night were i updated and plugged it in, it was at 60% and when i woke up it was at 46%.
Click to expand...
Click to collapse
So I let it run dry and am getting some weird behavior...
The dead battery symbol did not pop at all. It actually booted played the low battery sound half way through the nexus logo loaded into the OS and immediately was greeted by the battery to low logo powering down message and then it returned off. It did this cycle all the way through three times in a row before holding the power button did nothing. I let it sit for a minute before trying again and I got another boot out of it all the way to the OS again. But I've yet to be greeted by the battery with the cross symbol. Holding the power button will do the cycle described above or do nothing at all.
krisserapin said:
But while i was doing research I read that chargers up the current they dish out if the device is in use. Is that correct?
Click to expand...
Click to collapse
Well, the 120v->5v converter certainly can be providing more current @5v because the device is active, but that's only because the motherboard is drawing current in parallel with the battery charging circuit. It doesn't mean the battery charge rate is higher.
krisserapin said:
Could there really be a hardware related problem of any sort (not just charging and battery problems but anything) that causes problems with 4.2 based builds specifically but doesn't cause problems with 4.1?
Click to expand...
Click to collapse
I suppose so.
I would do a few things to determine whether that is a reasonable hypotheses, though.
1) See how fast the battery charges with the tablet turned off. Should be close to 40%/hour for a new battery. You know there is no "software" running with the tablet turned off, so if you don't see some reasonable number here (say > 20%/hr) then a bad battery or charge controller circuit in the tab are the most likely culprits. Also, if the temperature rise of the tablet while doing this seems higher than the gf's unit, that would implicate the battery, not the charging circuit.
2) There's software, and then there's software. (Preinstalled vs. User installed) Run the battery down a ways, and then observe the battery charging rate with the device on but screen off (sleeping), but on a stock 4.2 install with ZERO user apps installed. Then, install/restore all your favorite apps, reboot, maybe use a couple of your fave apps, and repeat the same charge rate trial (screen off/sleeping). Are there large differences between the two cases? If so, that would implicate one of your apps in causing either lots of additional compute operations or preventing entry into the LP0 state (perhaps because of wakelocks?)
The thing is, the N7 battery is rated at 4325 mAh; that is sort of the same thing as 4.325 amps of current for 1 hour. (Voltage range of roughly 4v to 3.5v).
So, if a "good battery" can be charged in 2.5hrs, that is sort of like stuffing 1.73 amps into the battery for that time (1.73 x 2.5 = 4.325 A-h or 4325 mA-h). That's pretty near to the max capacity of the AC charger (2A)
Now, some users have reported discharging their tabs in 4 hours under heavy continuous use; that would be about 1.08 amps for 4 hours.
Since the wall charger is rated to produce 2A, this suggests that very heavy usage simultaneous with charging would indeed cause battery charging to slow down significantly - let's suppose it drops from 1.73a to 0.65a. Now it takes the battery 6.6hrs to charge ... but that is still just over 15%/hr ... with the tab in active use.
But that's not what you were noticing - you were seeing much worse charge rates than this when the tablet was supposed to be more or less idle!
Finally I should point out that I previously mentioned that the % charge number is a prediction, not a measurement! If for some reason this number were screwed up, then the "charge rate" observations could be completely screwed up. (Think of this as being analogous to trying to partially fill a gas tank in a car or estimate fuel mileage with a broken gas gauge) The only way to be sure that you are not falling victim to something like this is to record battery voltages - the 100% level should be up around 4v, and the 10% values down around 3.5v.
You can observe this value at /sys/devices/platform/tegra-i2c.4/i2c-4/4-0055/power_supply/battery/voltage_now
(note value is reported in uV)
Whew - long post. It doesn't directly answer your question about "why was 4.1 so different?" - but gives you an idea about why I was skeptical when you saw charging rates as low as you did.
I dunno, maybe the % charge prediction value numbers are screwy on your tab for some strange reason in 4.2, perhaps because of a minor hardware difference. I can't rule it out - I once saw a bug expression in a hardware/software combination that required three independent conditions (from three separate vendors!) to have precise configurations before the bug would show itself.
I hope this post gives you some ideas to try; it certainly doesn't give a solution.
Good luck - if you feel like spending more time investigating, go for it; just don't let the clock run out on the warranty period if you have one left.
bftb0 said:
Well, the 120v->5v converter certainly can be providing more current @5v because the device is active, but that's only because the motherboard is drawing current in parallel with the battery charging circuit. It doesn't mean the battery charge rate is higher.
I suppose so.
I would do a few things to determine whether that is a reasonable hypotheses, though.
1) See how fast the battery charges with the tablet turned off. Should be close to 40%/hour for a new battery. You know there is no "software" running with the tablet turned off, so if you don't see some reasonable number here (say > 20%/hr) then a bad battery or charge controller circuit in the tab are the most likely culprits. Also, if the temperature rise of the tablet while doing this seems higher than the gf's unit, that would implicate the battery, not the charging circuit.
2) There's software, and then there's software. (Preinstalled vs. User installed) Run the battery down a ways, and then observe the battery charging rate with the device on but screen off (sleeping), but on a stock 4.2 install with ZERO user apps installed. Then, install/restore all your favorite apps, reboot, maybe use a couple of your fave apps, and repeat the same charge rate trial (screen off/sleeping). Are there large differences between the two cases? If so, that would implicate one of your apps in causing either lots of additional compute operations or preventing entry into the LP0 state (perhaps because of wakelocks?)
The thing is, the N7 battery is rated at 4325 mAh; that is sort of the same thing as 4.325 amps of current for 1 hour. (Voltage range of roughly 4v to 3.5v).
So, if a "good battery" can be charged in 2.5hrs, that is sort of like stuffing 1.73 amps into the battery for that time (1.73 x 2.5 = 4.325 A-h or 4325 mA-h). That's pretty near to the max capacity of the AC charger (2A)
Now, some users have reported discharging their tabs in 4 hours under heavy continuous use; that would be about 1.08 amps for 4 hours.
Since the wall charger is rated to produce 2A, this suggests that very heavy usage simultaneous with charging would indeed cause battery charging to slow down significantly - let's suppose it drops from 1.73a to 0.65a. Now it takes the battery 6.6hrs to charge ... but that is still just over 15%/hr ... with the tab in active use.
But that's not what you were noticing - you were seeing much worse charge rates than this when the tablet was supposed to be more or less idle!
Finally I should point out that I previously mentioned that the % charge number is a prediction, not a measurement! If for some reason this number were screwed up, then the "charge rate" observations could be completely screwed up. (Think of this as being analogous to trying to partially fill a gas tank in a car or estimate fuel mileage with a broken gas gauge) The only way to be sure that you are not falling victim to something like this is to record battery voltages - the 100% level should be up around 4v, and the 10% values down around 3.5v.
You can observe this value at /sys/devices/platform/tegra-i2c.4/i2c-4/4-0055/power_supply/battery/voltage_now
(note value is reported in uV)
Whew - long post. It doesn't directly answer your question about "why was 4.1 so different?" - but gives you an idea about why I was skeptical when you saw charging rates as low as you did.
I dunno, maybe the % charge prediction value numbers are screwy on your tab for some strange reason in 4.2, perhaps because of a minor hardware difference. I can't rule it out - I once saw a bug expression in a hardware/software combination that required three independent conditions (from three separate vendors!) to have precise configurations before the bug would show itself.
I hope this post gives you some ideas to try; it certainly doesn't give a solution.
Good luck - if you feel like spending more time investigating, go for it; just don't let the clock run out on the warranty period if you have one left.
Click to expand...
Click to collapse
Wow thank you so much for the help. I'll play around with this tonight and see what happens. If I can't figure it out by the morning I think I'll be able to RMA it without feeling like I just rolled over and let my n7 get the best of me.
So after charging it on stock 4.2.1 with the power completely off it only charged 3% in a little over a hour and voltages read 3.6. I'm gonna leave it on the charger over night turned on starting from 3% with only two extra battery monitoring apps installed and report back in the morning with screenshots of the results. After that ill probably revert to 4.1.2 drain the battery fully, charge it off for an hour report the values then let it charge fully with the battery apps on for reference take a few more screenshots then lock the bootloader install the ota and ship it off to good old ASUS since it sounds like its hardware from whats been explained.
FWIW, I drained my N7 last night (LOL, typing novels into XDA threads) - when I finished I was at 6% charge - that was 3.66v. In the morning @ 100%, the battery voltage was 4.1-something.
Sounds to me like you've definitely got a hardware problem.
Good luck with the RMA.
Canyou help me?
Since I flashed 4.2.2 my 240V-USB charger only cahrges thes battery about 5% in one hour.
Before (with 4.2.1) It was definitely faster. It charged more tha 5% per hour (maybe 20-25%).
I double checked the plug in the socket. checked the correct fit of the USB cable on the docking station.
Everything fits tight. No wiggle.
It must be software related, since it started after flashing the OTA zip from 4.2.1 to 4.2.2
Polarfuchs said:
Canyou help me?
Since I flashed 4.2.2 my 240V-USB charger only cahrges thes battery about 5% in one hour.
Before (with 4.2.1) It was definitely faster. It charged more tha 5% per hour (maybe 20-25%).
I double checked the plug in the socket. checked the correct fit of the USB cable on the docking station.
Everything fits tight. No wiggle.
It must be software related, since it started after flashing the OTA zip from 4.2.1 to 4.2.2
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From a partially charged state, say below 50%, turn the device off, (NOT sleeping, but powered OFF) and put it on the charger for one hour.
It should charge at around 30-40%/hr.
As I pointed out above, how is it possible that software would be affecting the charging with the device turned OFF?
I believe you are seeing exactly what you report; my best guess is that a hardware problem occurred just about coincidentally with your upgrade. Just coincidence - not causation.
You also should inspect the battery voltage (see above for path in /sys) in case something crazy is happening with the %charge *prediction* (it is not a measurement) - because the total charging range is from about 3.65v-4.15v, a normal charge rate should be roughly 150 to 200 mV/hr
good luck