I've read this thread started by JamesBarnes and it got me thinking. The setup he has done is good, but we actually have all those things in our phones. We've got a multimeter (current widget), we've got a power draining load (the phone itself) and the major drawback in his setup is eliminated. He is actually measuring the capacity of the battery to be compared with other batteries, but our phones protect the batteries by switching off with some charge left in the battery because LiIon batteries should not be drained completely. This means a/ you can't damage your battery by full cycling and b/ the phone does not use all the battery capacity. So HTC says 1230mAh, but what is the actual usable capacity of the battery? The most precise measurement should be with a constant minimal drain, but this will take too much time. The next best thing is the charge cycle. So I drained my battery untill shutdown. Then I powered on (I have fastboot enabled, so the phone turns off at 1% to have some energy left to power the memory while "off"), set the current widged to update at 30 sec, cleared the log and plugged in the charger. Then I turned off the screen and left the phone to fully charge overnight. In the morning I downloaded the log and calculated the energy that was pumped in the battery. The result is 1121 mAh. You can calculate yours too. You just have to sum the results of the charge current and then multiply the result to the time interval measured in hours (for 30 sec interval you should actually divide by 120). There is a small bug with current widget and it doesn't really log every period. Sometimes it's a bit more and sometimes it skips. So I wrote a small matlab program to calculate the exact capacity and if you want, you can send me your log of a full charge, or you can calculate it yourselves - just set a higher interval because this way the error will be smaller.
If anyone has a spare DHD (not likely) can leave the phone at airplane mode with 300 sec log interval and in a few days we'll have an exact value of the battery capacity.
tkolev said:
If anyone has a spare DHD (not likely) can leave the phone at airplane mode with 300 sec log interval and in a few days we'll have an exact value of the battery capacity.
Click to expand...
Click to collapse
No, what you will have is the exact capacity of one particular battery. LI-ion batteries vary in the charge they hold depending on how they have been used and for how long they have been used, so IMHO the above data would not be applicable to the community at large, also don't forget it's the DHD that decides when the battery is fully charged so that would add another uncertainty to the pot.
ghostofcain said:
No, what you will have is the exact capacity of one particular battery. LI-ion batteries vary in the charge they hold depending on how they have been used and for how long they have been used, so IMHO the above data would not be applicable to the community at large, also don't forget it's the DHD that decides when the battery is fully charged so that would add another uncertainty to the pot.
Click to expand...
Click to collapse
The purpose of my post was to explain how can anyone measure their own batteries. I don't care about yours, you don't care about mine - that's for sure. But how can you know when buying a replacement battery that the xxxx mAh written on the back is true (and it usualy isn't)? "Lasting longer" is subjective and my method gives you an objective measurement. My battery is five month's old. 1121mAh is a plausable value proving that the method works. If you don't want to bother to do the math yourself, you can send me the log, so I'll do it for you. If you want to know about the current capacity of your battery - fine. If you don't want to know - it's also fine. Also if we can gather some precise measurements (minimizing the error by using constant drain over a longer period) on the capacity we can eliminate the error introduced by the different units and we'll know what to expect from stock batteries and thus we can compare the non-OEM ones to them.
plus, Li-ions usable capacitys change with the batterys temperature and current. How is knowing that my battery could give me 1100mAh @ 5mA/300K of any value to me if I usually need my phone @200mA/280K? Measuring while charging ain't the best idea either, because heat dissipated by the battery during the process will show up in your reading. (and dissipated heat is not the kind of energy that you'd call 'usable')
Also, I am not really sure, how bumping the interval up, thus generating less discrete measurements, is going to increase accuracy...
llama-power said:
plus, Li-ions usable capacitys change with the batterys temperature and current. How is knowing that my battery could give me 1100mAh @ 5mA/300K of any value to me if I usually need my phone @200mA/280K? Measuring while charging ain't the best idea either, because heat dissipated by the battery during the process will show up in your reading. (and dissipated heat is not the kind of energy that you'd call 'usable')
Also, I am not really sure, how bumping the interval up, thus generating less discrete measurements, is going to increase accuracy...
Click to expand...
Click to collapse
As I have said in the first post, it's best to measure the drain, not the charge, but unfortunately I can't spare the time needed without using my phone to take that measurement. The fact is that I don't know how current widget logs the current. Is it measured at the beggining of the interval, the end, is it a mean value over the whole interval, the max, the min? So we should have as constant drain as possible. That way we will eliminate the effect of different measuring methods.
The longer period is just for ease of use. Have you seen a current widget log with interval of 30 seconds? There are many missing intervals, others are 40 sec, 50 sec and the simpler method (summing up the values and multiplying by the time) doesn't work, so it won't be suitable for everyone to calculate the capacity by their own. And with a constant drain the longer period won't introduce that much of an error in the calculation.
You can't have a precise measurement for all the situations you might think of. Some days I talk over the phone for 30 minutes, some days I talk for over an hour. Some days I read e-books, other days I watch videos. The different drain causes different usable capacity as you know. The only thing that's common with the phone day-to-day usage is the stand-by periods. This might have a negative impact on the accuracy because with digital reading you have quantization which introduces bigger error on small values, but this remains to be seen. If you can have constant drain at say... 50 mAh (roughly 1:2 usage pattern), it will introduce max 2% error (depending on the value reading method by the phone). And I don't know about you, but I think 2% is nothing when dealing with something so variable like the battery capacity.
Related
i spoke to htc about the abysmal battery life, they say that there could be extended batteries in the near future, with a new back cover (with the back sticking out)
i dont mind charging it every day but
everytime i do something basic, for couple of minutes, it goes down by 1 percent, everything is turned off, gsm 2g mode, etc.
anyway the guy at htc said its due to the massive screen, this is what drains majority of the juice,
For what this device has and what it can do the battery life is pretty good, if you just use it for a few random pics, bit of browsing, bit of music and a few calls you should get a days use, if you sit there for ages messing with it its gonna drain.
Im pleased with it myself, apart from the bugs, but waiting......
It's killing you literally? Step away man!
I find the battery life on-par with other smart phones I've owned. I use a desktop cradle (well should soon be using a desktop cradle) and an active holder in the car, so I find the battery keeps up OK with a typical day's use for me. The biggest battery killer is when the screen is on full brightness so I find essential to have the phone on power when I'm using the satnav.
I had really high hopes for this thread when I read the title. Needless to say, I'm pretty disappointed.
Where's the death I was promised?
Die and prove it.
mox123 said:
i spoke to htc about the abysmal battery life, they say that there could be extended batteries in the near future, with a new back cover (with the back sticking out)
i dont mind charging it every day but
everytime i do something basic, for couple of minutes, it goes down by 1 percent, everything is turned off, gsm 2g mode, etc.
anyway the guy at htc said its due to the massive screen, this is what drains majority of the juice,
Click to expand...
Click to collapse
To be fair most smartphones drain their batteries pretty damned quickly. Disconnect your data connection when you're not using it and bluetooth too. OK so you won't get weather updates but you'll save battery life. Just charge it nightly and buy a car charger if you really drain that sucker!
Wow, I think battery life is good considering the screen, better than I expected.
Currently, with screen set to 70% brightness, push email on 0800-1800 with hourly retrieval outside those hours, hourly weather/Twitter update, automatic Quick-GPS almanac data update, I last all day (~0700 to 2300), and still with about 20-30% headroom with the following use:
Push email as per above settings
50 minutes GPS tracking
50 minutes bluetooth on (heart rate monitor)
1-2 hours listening to music
Around 1-2 hours high-drain use (screen on, using cellular data/WiFi/GPS - for example browsing/app use/gaming/watching video)
30-40 SMS
15 minutes calls
One simple little trick that I learnt some time ago to preserve battery life is ..........turn down the brightness of the screen display. The brighter it is the more juice gets used.
Get the screen to turn itself off after, say, 30 secs of use. That also helps.
The rest, such as killing off data connections when not in use, etc, you already know.
It never ceases to surprise me at the number of negative comments re battery life. The impression I am left with is that if the battery does not last at least 2 months between charges, even though it is being hammered to within an inch of it's life, then that makes the battery performance rubbish. Anyone ever heard of a battery charger?
It's a really easy to use piece of kit that comes with your device that can be plugged in at night when you are asleep, leaving your device fresh for the morning.
Amazing.
WB
What the heck do you expect from such a phone? The energy management is kinda good and it's the display that kills battery life. You have to get use to it. At least my Touch HD seems to last much longer, but I would never change back.
If you watch a video your battery capacity drops quickly. I estimated 4,3-4,5h of HW-acc WVGA video and 3,5h with a non-HW-acc VGA video. Not that much but it really looks fantastic.
My Solution for this problem is: second battery, extended battery and/or load the battery whereever u can. My normal usage drains 30% of the battery a day, so I get 3 days of normal usage (I'm not an excessive handy user). The standby duration is with 300h not that good, but yeah that means still 12,5 days of standby if I calculated correctly.
The point is, that the phone is that good that I'm attracted to play with it and then the battery life tends to last just a day or less.
I bought a second battery (~22€) just for longer rides. I think it's ok.
mox123 said:
i spoke to htc about the abysmal battery life, they say that there could be extended batteries in the near future, with a new back cover (with the back sticking out)
i dont mind charging it every day but
everytime i do something basic, for couple of minutes, it goes down by 1 percent, everything is turned off, gsm 2g mode, etc.
anyway the guy at htc said its due to the massive screen, this is what drains majority of the juice,
Click to expand...
Click to collapse
EEK!, don't come on this forum and complain about the HD2! not allowed. this is now the official HD2 Appreciation society, don't ya know.
I recommend instead you buy some lube oil, massage it into the device, light some candles, play a bit of Barry White, and all will be well.
Then come on this site and reassure all the sensitive souls here that it is indeed the Holy Grail of mobiles and admit you are a Troll for finding a fault with it, and daring to ask about why it does not preform as it says on the tin.
And final advice...In the words of legendary Basil Fawlty... Don't mention the War !..or in this case, the Keyboard!!, I mentioned it once...and thought I got away with it..but no.
hawrai68 said:
EEK!, don't come on this forum and complain about the HD2! not allowed. this is now the official HD2 Appreciation society, don't ya know.
I recommend instead you buy some lube oil, massage it into the device, light some candles, play a bit of Barry White, and all will be well.
Then come on this site and reassure all the sensitive souls here that it is indeed the Holy Grail of mobiles and admit you are a Troll for finding a fault with it, and daring to ask about why it does not preform as it says on the tin.
And final advice...In the words of legendary Basil Fawlty... Don't mention the War !..or in this case, the Keyboard!!, I mentioned it once...and thought I got away with it..but no.
Click to expand...
Click to collapse
Nice one.
NetDwarf said:
What the heck do you expect from such a phone? The energy management is kinda good and it's the display that kills battery life. You have to get use to it. At least my Touch HD seems to last much longer, but I would never change back.
If you watch a video your battery capacity drops quickly. I estimated 4,3-4,5h of HW-acc WVGA video and 3,5h with a non-HW-acc VGA video. Not that much but it really looks fantastic.
My Solution for this problem is: second battery, extended battery and/or load the battery whereever u can. My normal usage drains 30% of the battery a day, so I get 3 days of normal usage (I'm not an excessive handy user). The standby duration is with 300h not that good, but yeah that means still 12,5 days of standby if I calculated correctly.
The point is, that the phone is that good that I'm attracted to play with it and then the battery life tends to last just a day or less.
I bought a second battery (~22€) just for longer rides. I think it's ok.
Click to expand...
Click to collapse
Exactly !!
1000 Mhz this bugger does.
And really its more then just a phone. with the battery cunsumption like wise.
But they told me one thing,,. something that Noone does
When you get the HD2. Its battery got 20% juice init.
Thats not for fun of the company (prolly sanyo) was laizy and dint bother to fill em 100%.
You have to charge the battery 6 to 12 hours and to peeking at your new jewel.
And i know Noone ever does that. But it ensures batterylife and eficiency
Here is the article >>
Initialize a new battery. New batteries should be fully charged before their first use to obtain maximum capacity.
Nickel-based batteries should be charged for 16 hours initially and run through 2-4 full charge/full discharge cycles, while lithium ion batteries should be charged for about 5-6 hours.
Ignore the phone telling you that the battery is full--this is normal but is not accurate if the battery is not initialized.
#DO NOT fully discharge a lithium-ion battery!
Unlike Ni-Cd batteries, lithium-ion batteries' life is shortened every time you fully discharge them.
Instead, charge them when the battery meter shows one bar left.
Lithium-ion batteries, like most rechargeable batteries have a set amount of chargers in them.[1]
2Keep the battery cool.
Your battery will last longest if used near room temperature, and nothing wears on a battery like extended exposure to high temperatures. While you can’t control the weather, you can avoid leaving your phone in a hot car or in direct sunlight, and you don’t have to carry your phone in your pocket, where your body heat will raise its temperature.
In addition, check the battery while it’s charging. If it seems excessively hot, your charger may be malfunctioning.
3Charge your battery correctly, in accordance with its type. Most newer cell phones have lithium-ion batteries, while older ones generally have nickel-based batteries. Read the label on the back of the battery or in the technical specifications in the manual to determine which yours is.
Nickel-based batteries (either NiCd or NiMH) DO NOT generally suffer from a misunderstood phenomenon known as the "memory effect." As described in Wikipedia and many expert sources,[2] the term "memory effect" has been widely mythologized to describe any and all deterioration of NiCd (and other battery chemistries), in many cases misleading consumers into further shortening the lives of the batteries through over-discharging to "recondition" them.[3]
[This section formerly read: If you charge the battery partially enough times, eventually the battery "forgets" that it can charge fully. A nickel-based battery suffering from memory effect can be reconditioned, which requires the battery to be completely discharged, then completely recharged (sometimes several times). The appropriate length of time between reconditionings varies. A good rule to follow for nickel-battery cell-phones is to discharge them completely once every two to three weeks, and only when you have a charger available. [4] ]
Lithium ion batteries can be preserved by careful charging and avoiding storing them at full charge.[5] They do not require "reconditioning."
Regardless of the battery type, use only a charger rated for your battery, and discontinue use of a charger that causes the battery to heat up excessively.
Enonoid said:
Exactly !!
1000 Mhz this bugger does.
And really its more then just a phone. with the battery cunsumption like wise.
But they told me one thing,,. something that Noone does
When you get the HD2. Its battery got 20% juice init.
Thats not for fun of the company (prolly sanyo) was laizy and dint bother to fill em 100%.
You have to charge the battery 6 to 12 hours and to peeking at your new jewel.
And i know Noone ever does that. But it ensures batterylife and eficiency
Here is the article >>
Initialize a new battery. New batteries should be fully charged before their first use to obtain maximum capacity.
Nickel-based batteries should be charged for 16 hours initially and run through 2-4 full charge/full discharge cycles, while lithium ion batteries should be charged for about 5-6 hours.
Ignore the phone telling you that the battery is full--this is normal but is not accurate if the battery is not initialized.
#DO NOT fully discharge a lithium-ion battery!
Unlike Ni-Cd batteries, lithium-ion batteries' life is shortened every time you fully discharge them.
Instead, charge them when the battery meter shows one bar left.
Lithium-ion batteries, like most rechargeable batteries have a set amount of chargers in them.[1]
2Keep the battery cool.
Your battery will last longest if used near room temperature, and nothing wears on a battery like extended exposure to high temperatures. While you can’t control the weather, you can avoid leaving your phone in a hot car or in direct sunlight, and you don’t have to carry your phone in your pocket, where your body heat will raise its temperature.
In addition, check the battery while it’s charging. If it seems excessively hot, your charger may be malfunctioning.
3Charge your battery correctly, in accordance with its type. Most newer cell phones have lithium-ion batteries, while older ones generally have nickel-based batteries. Read the label on the back of the battery or in the technical specifications in the manual to determine which yours is.
Nickel-based batteries (either NiCd or NiMH) DO NOT generally suffer from a misunderstood phenomenon known as the "memory effect." As described in Wikipedia and many expert sources,[2] the term "memory effect" has been widely mythologized to describe any and all deterioration of NiCd (and other battery chemistries), in many cases misleading consumers into further shortening the lives of the batteries through over-discharging to "recondition" them.[3]
[This section formerly read: If you charge the battery partially enough times, eventually the battery "forgets" that it can charge fully. A nickel-based battery suffering from memory effect can be reconditioned, which requires the battery to be completely discharged, then completely recharged (sometimes several times). The appropriate length of time between reconditionings varies. A good rule to follow for nickel-battery cell-phones is to discharge them completely once every two to three weeks, and only when you have a charger available. [4] ]
Lithium ion batteries can be preserved by careful charging and avoiding storing them at full charge.[5] They do not require "reconditioning."
Regardless of the battery type, use only a charger rated for your battery, and discontinue use of a charger that causes the battery to heat up excessively.
Click to expand...
Click to collapse
It's a shame most powerful mobiles heat up like nobody's business whilst on full chat these days.....there's no chance of keeping the batteries cool! Still, it's an expendable item and at least you can buy a replacement.....none of this iPhone 'sealed' tin rubbish.
while i find the battery life reasonable with the features this phone has (read screen size, processor speed), it will be nice to get the CPU throttling app another thread is discussing. don't need that 1000MHz running everytime i pick the phone.
On the same notes, how can i check if automatic screen brightness is kicking in?
here4info said:
how can i check if automatic screen brightness is kicking in?
Click to expand...
Click to collapse
Stick the phone under a bright light such as a desk lamp and cover the light sensor with a piece of paper.
here4info said:
while i find the battery life reasonable with the features this phone has (read screen size, processor speed), it will be nice to get the CPU throttling app another thread is discussing. don't need that 1000MHz running everytime i pick the phone.
On the same notes, how can i check if automatic screen brightness is kicking in?
Click to expand...
Click to collapse
It certainly isn't running when I boot my phone up....hardly gives an impression of speed.
mox123 said:
i spoke to htc about the abysmal battery life, they say that there could be extended batteries in the near future, with a new back cover (with the back sticking out)
i dont mind charging it every day but
everytime i do something basic, for couple of minutes, it goes down by 1 percent, everything is turned off, gsm 2g mode, etc.
anyway the guy at htc said its due to the massive screen, this is what drains majority of the juice,
Click to expand...
Click to collapse
are you the first wm phone user? Do you have good experience with phones that has so much specs? Do you use wifi and browse with phone very heavily? If you do, it is really normal that the battery will drain. My Touch HD does the same, it can last a day or 2 or drain like water not more than half a day, it depends on your usage. Try to get a second battery, or even the third one like I do, what is a big deal? It is completely normal.
I don't have a lot complaints on this phone as it meets most of my requirements.about the battery, I seriously don't think it is that bad. for example if you have a car with 1500 horse power and expect it to have or rather 30-40 mpg, don't think it is possible. try to use your local gas station (in this case your friendly charger) more often.move on with your life please.
c4Lvin said:
I don't have a lot complaints on this phone as it meets most of my requirements.about the battery, I seriously don't think it is that bad. for example if you have a car with 1500 horse power and expect it to have or rather 30-40 mpg, don't think it is possible. try to use your local gas station (in this case your friendly charger) more often.move on with your life please.
Click to expand...
Click to collapse
That might be a little difficult because this battery problem is killing him, LITERALLY
Hey everyone,
I'm kind of a noob when it comes to all things XDA (but I'm learning.) Anyways, I was wondering what kind of battery life you all get from the different ROMs you've flashed.
So far I've only flashed Nero, Bionix, and Flagship. I had pretty good battery life from Nero, but I was wondering what kind of battery life that you've experienced with other ROMs like Axura and Trigger (because with Bionix and Flagship, my battery life has been fugazi.)
Thanks in advance, y'all.
Sorry if this topic comes up often.
With axura my battery lasts 16 hours with possibly 600+ texts and youtube alot music about 1 hour a few phone calls alot of web.
I only need it to last 12 hours because I charge overnight so I'm good.
I reconditioned too btw
Does reconditioning actually improve battery life or does it simply make the battery indicator more accurate?
It makes it more accurate. Which in terms helps battery because it reads it perfect so ull last longer
Axura is widely considered to have the best battery life. After flashing a new rom you should let your phone charge to 100% and then wipe battery stats in CWM recovery. It can take several days for reading to be taken from the battery so your battery life will usually improve over time.
Hey, I just wanted to thank you all for your input. I decided to go with the latest version of Axura, and so far I've been loving it. I'm not even a day in and I've noticed a difference.
Thanks once again.
+1 On Axura best battery life........
soltheman said:
Hey everyone,
I'm kind of a noob when it comes to all things XDA (but I'm learning.) Anyways, I was wondering what kind of battery life you all get from the different ROMs you've flashed.
So far I've only flashed Nero, Bionix, and Flagship. I had pretty good battery life from Nero, but I was wondering what kind of battery life that you've experienced with other ROMs like Axura and Trigger (because with Bionix and Flagship, my battery life has been fugazi.)
Thanks in advance, y'all.
Sorry if this topic comes up often.
Click to expand...
Click to collapse
first thing to do is
Charge Until 100%
choose rom
Run The Phone All Day, Let It Die
Charge Until 100%
Reboot Into Recovery
Select Reinstall Packages (Do it again if needed)
Select Advanced
Select Wipe Battery Stats
Laazyboy said:
Does reconditioning actually improve battery life or does it simply make the battery indicator more accurate?
Click to expand...
Click to collapse
Neither. "Conditioning" skews the discharge curve from which the battery indicator indexes it percentages. As a result, the battery appears to discharge at slower rate ("better battery life") over the first two-thirds or so of the discharge cycle and then craters like a lead balloon at the end of the discharge cycle. (You really need to have a battery indicator that shows discharge in 1% increments, such as "blue segmented battery mod" to see this.)
To understand this requires a light understanding of the so-called "battery stat tables." There is an entry in the battery stat tables for each percentage of remaining battery charge, in increments of 1%. So, the table contains entries 100%, 99%,... down to 1%. Associated with each percent of remaining charge entry in the table is a battery terminal voltage and a timestamp. Unfortunately, the smart phone cannot measure actual remaining battery charge. All the system knows is a series of battery terminal voltage measurement taken at even periodic intervals. The algorithm builds the battery stat table to relate each measured voltage to a corresponding “percentage of remaining charge” entry in the table. In normal operation, the system accumulates these measurements over several charge/discharge cycles and analyzes the rates of changes of voltages to refine the discharge curve. After several charge/discharge cycles the percentages, which are displayed on the screen as a battery indicator, become more refined and accurate.
At some point someone apparently thought that it would be a good idea to attempt to manipulate the process of building the battery stat tables. This resulted in the so-called "conditioning procedure." The conditioning procedure consists of fully charging the battery, then deleting the battery stats, and then draining the battery quickly and completely using heavy loads, perhaps in 1 to 2 hours.
What this accomplishes is that the battery stat mechanism builds a new, steep discharge curve based upon the rapid discharge operation. This crude, initial discharge curve has "learned" that the battery should discharge quickly, because it did so during its "training” discharge. More specifically, each "percentage discharge" entry for the first 1/2 to 2/3 of the discharge curve (corresponding to the first 50-75 table entries) will be associated with an abnormally lower voltage (due to the faster rate of decrease in voltage during the "training" discharge cycle) than would be the case if the table had been built normally, over time.
Now, let us think about what happens during the subsequent discharge cycle. We charge the battery to full. Now we begin to use the phone normally, discharging the unit over a period of 12-18 hours, for example. Now the phone experiences a slower rate of change of battery voltage over time, because the load is much lower than that of the forced "training" discharge. Now the algorithm measures a voltage and then attempts to map that voltage to a corresponding percentage discharge table entry. The result is that the battery indicator on the phone shows a very low rate of discharge over many hours. This leads people to erroneously conclude that the "battery conditioning" procedure results in improved battery life. However, this is merely an illusion. The battery indicator is, at this point, simply displaying an incorrect number for the remaining battery life. As a consequence, the battery indicator must "catch up with reality" later in the discharge cycle. This is manifested toward the end of the discharge cycle as the battery indicator drops precipitously from perhaps 35% to zero in a very small amount of time. In any case, fortunately, the weirdness done by "battery conditioning" goes away within a few days as the battery stat algorithm tunes the discharge curve each discharge cycle to bring it ever further in line with the actual average usage of the phone owner. It is a myth that the battery stats become inaccurate over time. To the contrary, the algorithm continuously tunes the tables based upon usage patterns so that the battery indicator becomes more and more accurate.
I do not know where this practice originated, but I do have a cynical hypothesis. The ROM cookers typically mix-and-match code elements from different software releases and otherwise change up the timing, sequencing, etc. of various processes. Doing so may have battery life consequences, because the resulting mish-mash of components may hinder or prevent sleep mode operation, cause processes to run for more time than they should, etc. You can see how "battery conditioning" could mask an acute battery performance problem during the first few hours after a person has flashed a ROM and is watching performance characteristics especially closely. ‘Nuf said on this subject.
Sample battery discharge chart and accompanying notes attached below.
soltheman said:
Hey everyone,
I'm kind of a noob when it comes to all things XDA (but I'm learning.) Anyways, I was wondering what kind of battery life you all get from the different ROMs you've flashed.
So far I've only flashed Nero, Bionix, and Flagship. I had pretty good battery life from Nero, but I was wondering what kind of battery life that you've experienced with other ROMs like Axura and Trigger (because with Bionix and Flagship, my battery life has been fugazi.)
Thanks in advance, y'all.
Sorry if this topic comes up often.
Click to expand...
Click to collapse
Tutorial for tuning system to increase battery life here:
http://forum.xda-developers.com/showthread.php?t=823025&page=4
xriderx66 said:
With axura my battery lasts 16 hours with possibly 600+ texts and youtube alot music about 1 hour a few phone calls alot of web.
I only need it to last 12 hours because I charge overnight so I'm good.
I reconditioned too btw
Click to expand...
Click to collapse
600 texts in 16 hours is nearly 38 texts an hour, 4,200 texts a week, 18,000 texts every month. WTFBBQ?
hi there!i am new to XDA. can anyone of you guys help me out with my battery problems.
I have a asus P320 windows phone . it shuts down itself when the power is still 70% . is there anyway to change the registry settings to prevent the auto shutdown due to low battery. i would'nt have bothered with this shutdown if the battery was old but i bought a brand new battery , and no matter what the ROM is it still switches off . I would really appreciate if someone could help me on this.
is there any way to change any of the registry values to disable the lowbattery warning and the autoshutdown.
The battery is not truly measured by "capacity". The capacity is derived from measurable data, mainly the voltage. The voltage for new batteries is very little depending on the load which is applied to battery. Over time (and charge cycles) however the chemistry in the battery is aging so that the load on the battery lets the voltage drop when load is applied. Load is anything like the CPU demand, lights on and so on.
So for your case it is highly probable that idle the battery shows 70% but when load is applied, the voltage drops below the shut off point and the device is off. There is no option to adjust this - it is hard-coded in the battery driver.
Have a look at my battery measurement thread linked from my signature to get some background and find a method to track this.
To give you a rough hint: fully charged, the device should be able to stay on with LCD light (fully lit) on for several hours. With what you report it should go off within less than 2 hours from my estimate.
tobbbie said:
The battery is not truly measured by "capacity". The capacity is derived from measurable data, mainly the voltage. The voltage for new batteries is very little depending on the load which is applied to battery. Over time (and charge cycles) however the chemistry in the battery is aging so that the load on the battery lets the voltage drop when load is applied. Load is anything like the CPU demand, lights on and so on.
So for your case it is highly probable that idle the battery shows 70% but when load is applied, the voltage drops below the shut off point and the device is off. There is no option to adjust this - it is hard-coded in the battery driver.
Have a look at my battery measurement thread linked from my signature to get some background and find a method to track this.
To give you a rough hint: fully charged, the device should be able to stay on with LCD light (fully lit) on for several hours. With what you report it should go off within less than 2 hours from my estimate.
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Thank you for the quick reply. well, the battery does'nt last much time though . i tried to discharge the old battery (which i still have) to 0% and when i charge it for some time and switchoff the charger it shows some % of batter left and after sometime it shutsdown showing lowbattery warning.
I can understand this happening @ 5% or even 15%but @ 60%- 70% on a brand new battery is a bit much.
if only i could just prevent the autoshutdown, in the mean time i have to check on your battery measurement thread/
From my battery thread I have linked some info on battery chemistry. Bottom line is that LiIon batteries are aging from the day they are produced and the dependency on charge cycles or discharge depth is minimal (different to older type NiMH batteries). So even if you buy a "new" battery in the shop it may be 5 years old from its production date already.
My experience with after-market batteries (so non-original) is very bad. You almost never get good quality and usually old original batteries perform better. I have lots of batteries checked on the Typhoon/Hurricane/Tornado and several on Vox/Excalibur. Especially the true original branded like Sanyo, Celxpert or Samsung have sometimes exceptional performance. I have some of these that already have 5 years (of little to modest use) and still have their nominal capacity. Recently I bought an original packed battery for the Qtek 8310 (Celxpert) which should be 5 years old - and this one has its original capacity! On the other hand I have also bought cheap Chinese that have only 30% of the labeled capacity.
I am new to this forum
Just wanna ask if i switch on my nexus7 wifi 24*7 then will it affect its wifi??
Just curious to know becoz i rarely switch off my wifi and i am scared will itt damage it after sometime??
Heat accelerates almost all aging & failure mechanisms.
Temperature cycling accelerates some types of failure mechanisms (fracture/rupture type failures)
So leave it on or turn it off every night, which is worse?
So long as you aren't streaming data at full bore 24x7 you will probably be fine leaving it on.
Note I said *probably*. That's because I certainly do not have accelerated life-test data for the N7 sitting in front of me; but even if I did, those statistics would only predict what fraction of units would fail over yeah-many hours/years of service... not which individual units will fail.
So unless someone from Asus comes in here and divulges what their MTBF design goal for the N7 was, or what the first 18 months of the repair stream has indicated about their reliability models, you're not going to get much of an answer to your inquiry.
FWIW, I leave mine on the charger & with the WiFi on when I am not using it, and I have the expectation of using it for a couple more years to come.
bftb0 said:
Heat accelerates almost all aging & failure mechanisms.
Temperature cycling accelerates some types of failure mechanisms (fracture/rupture type failures)
So leave it on or turn it off every night, which is worse?
So long as you aren't streaming data at full bore 24x7 you will probably be fine leaving it on.
Note I said *probably*. That's because I certainly do not have accelerated life-test data for the N7 sitting in front of me; but even if I did, those statistics would only predict what fraction of units would fail over yeah-many hours/years of service... not which individual units will fail.
So unless someone from Asus comes in here and divulges what their MTBF design goal for the N7 was, or what the first 18 months of the repair stream has indicated about their reliability models, you're not going to get much of an answer to your inquiry.
FWIW, I leave mine on the charger & with the WiFi on when I am not using it, and I have the expectation of using it for a couple more years to come.
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recently i played hd movie on my nexus 7
(Movie-300 blue ray version
Frame width-1280
Frame height- 544
frame rate - 23 frames per sec )
and found playback time of 5hrs only
I didn't played entire movie jst calculated in the form that my battery level reduced from 93 to 92 in exact 3 min
Like this i calculate entire playback time ,....
But on internet it says nexus 7 support 9 hrs of hd playback
Plz tell 5 hrs playback is fine for bluray version or I'm having some sought of a battery issue
And if it's a battery issue then what shall i do for its replacement because its been only 1 months
Plz do reply asap.
Regards.
nitu12345 said:
recently i played hd movie on my nexus 7
(Movie-300 blue ray version
Frame width-1280
Frame height- 544
frame rate - 23 frames per sec )
and found playback time of 5hrs only
I didn't played entire movie jst calculated in the form that my battery level reduced from 93 to 92 in exact 3 min
Like this i calculate entire playback time ,....
But on internet it says nexus 7 support 9 hrs of hd playback
Plz tell 5 hrs playback is fine for bluray version or I'm having some sought of a battery issue
And if it's a battery issue then what shall i do for its replacement because its been only 1 months
Plz do reply asap.
Regards.
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Click to collapse
Three minutes (or a 1% change) in battery "percent charge state" is way way too small of an interval to extrapolate from - the sampled data is just way too noisy to be meaningful. A 10% change would be a better measurement. And, those types of measurements should be made in the "middle" of the battery charge state (in the 30% - 70% range, not near the ends).
But - to answer your question - quite a long time ago, @bcvictory ran many battery drain tests - using a video loop test - with a bunch of different kernels, and most of the results tended to be between 5 and 7 hours or so.
I made some very detailed battery drain measurements playing a video loop about 4 weeks ago on my N7 (MX Player), and without tweaking anything (stock kernel, KitKat 4.4.2) I got about 6.25 hrs for a full discharge (100% - 4%).
So, I guess that means that if you saw an Asus/Google claim of 9 hours, that would probably be a significant exaggeration.
(BTW, keep in mind that for *movies* the GPU isn't doing all that much work, as the scenes are not being rendered from a model - they are just being decompressed from a file (or byte stream). So... that means that you should probably expect even worse battery drain times for playing video games continuously).
.
nexus 7 overcharging
bftb0 said:
Three minutes (or a 1% change) in battery "percent charge state" is way way too small of an interval to extrapolate from - the sampled data is just way too noisy to be meaningful. A 10% change would be a better measurement. And, those types of measurements should be made in the "middle" of the battery charge state (in the 30% - 70% range, not near the ends).
But - to answer your question - quite a long time ago, @bcvictory ran many battery drain tests - using a video loop test - with a bunch of different kernels, and most of the results tended to be between 5 and 7 hours or so.
I made some very detailed battery drain measurements playing a video loop about 4 weeks ago on my N7 (MX Player), and without tweaking anything (stock kernel, KitKat 4.4.2) I got about 6.25 hrs for a full discharge (100% - 4%).
So, I guess that means that if you saw an Asus/Google claim of 9 hours, that would probably be a significant exaggeration.
(BTW, keep in mind that for *movies* the GPU isn't doing all that much work, as the scenes are not being rendered from a model - they are just being decompressed from a file (or byte stream). So... that means that you should probably expect even worse battery drain times for playing video games continuously).
.
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Sir by mistake i overcharged nexus7 tablet for 1 hour and found out that
That it didn't get discharged for next 1 hour ( in which i surf web , watch youtube videos,and played temple run )
Don't you think it get overcharged for i hour because last time i removed the charger at exact 100 % and it started draining within that i hour
And plz do tell even if tablet gets overcharged
Is it safe ?
Becoz i usually charge my tablet at night.
nitu12345 said:
Sir by mistake i overcharged nexus7 tablet for 1 hour and found out that
That it didn't get discharged for next 1 hour ( in which i surf web , watch youtube videos,and played temple run )
Don't you think it get overcharged for i hour because last time i removed the charger at exact 100 % and it started draining within that i hour
And plz do tell even if tablet gets overcharged
Is it safe ?
Becoz i usually charge my tablet at night.
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Click to collapse
I wrote a script to "watch" the battery current and voltage in my N7 once per minute (while it was charging from about 4% - 100%) and log the output to a file. (see attached image). So, I think I know exactly why you saw the results you did.
So here is what happens: as the battery voltage rises during charging, the current slowly gets smaller and smaller. Somewhere around 90% the current suddenly starts to slow down much faster in time, and the battery voltage only rises a tiny bit over the 90% - 100% interval.
Here was the surprise though: when the "% charge" got to 100%, the battery continued to charge (slowly) for another 20 minutes. Over that 20 minutes the battery charging current eventually went to zero.
So - it is safe to let your tablet sit on the charger. It is not the charger that determines how much current the battery receives, it is the SMB347 chip in the N7. There is no such thing as "overcharging" so long as the hardware in the tablet is operating correctly. I leave my tablet on the charger all the time when I am not using it, and don't worry about that one bit.
bftb0 said:
I wrote a script to "watch" the battery current and voltage in my N7 once per minute (while it was charging from about 4% - 100%) and log the output to a file. (see attached image). So, I think I know exactly why you saw the results you did.
So here is what happens: as the battery voltage rises during charging, the current slowly gets smaller and smaller. Somewhere around 90% the current suddenly starts to slow down much faster in time, and the battery voltage only rises a tiny bit over the 90% - 100% interval.
Here was the surprise though: when the "% charge" got to 100%, the battery continued to charge (slowly) for another 20 minutes. Over that 20 minutes the battery charging current eventually went to zero.
So - it is safe to let your tablet sit on the charger. It is not the charger that determines how much current the battery receives, it is the SMB347 chip in the N7. There is no such thing as "overcharging" so long as the hardware in the tablet is operating correctly. I leave my tablet on the charger all the time when I am not using it, and don't worry about that one bit.
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That means my battery's working fine..na??
Can u suggest me a gud free app to scan battery's performance?
Hws BetterBatteryStats_xdaedition_1.15.0.0 ?
And thanks a lot for clearing my doubts
U r bst
What does "Battery Charge %" Mean?
nitu12345 said:
That means my battery's working fine..na??
Can u suggest me a gud free app to scan battery's performance?
Hws BetterBatteryStats_xdaedition_1.15.0.0 ?
And thanks a lot for clearing my doubts
U r bst
Click to expand...
Click to collapse
@nitu12345 - I don't use battery monitoring apps. I'm not really sure what value they have except in deciding whether or not your battery is sort of "normal". Some of them try to "estimate" current rather than actually take measurements from hardware (which depends on the availability of both system hardware and kernel software, so it makes sense why a generic Android battery app might not even look at current measurements even when they are available on a particular handset/tablet) , so: garbage-in = garbage-out. Basically though, I can't make a recommendation as I haven't used them.
TL;DR - see attached plots at end of post.
I want to take this opportunity to show some more data that I measured in the hopes that it can add to folk's understanding. I made a bunch of measurements of my tablet under both discharge and charging conditions, Originally I was going to make a big long post, but it was simply too much effort to do a good job of it with all the data I had. So here is a mini-report about charging. In particular, it asks and answers the question:
"What exactly does charge percentage mean"?
Is it the measurement of Amp-hours pumped into the battery?
Or is it somehow proportional to battery voltage?
Something else?
Before I begin I should point out just a few key observations. The 2012 N7 has a TI (Texas Instruments) chip - the BQ27541 (iirc), that has the sole purpose of observing the battery - the amount of current going into or out of the battery, and the battery voltage. It does NOT CONTROL ANYTHING - it is just an observer. For that reason, TI calls it a "fuel gauge" chip. It is connected to the processor via an I^2C bus, and the N7's kernel reads the "% charge" directly from this chip. There is no system "battery software" or "calibration software" which alters this number in the N7 - it comes directly from that BQ27541 chip. No doubt there is a tiny amount of firmware in that chip, and the datasheet for that chip indicates it can be factory programmed with different battery curves. But for our purposes it is a black box that we can't easily change - the kernel interface on the N7 does none of that "factory programming", it just reads values from the "black box".
From that chip several things can be read - "% charge", "battery current", "voltage", etc.
Attached at the bottom of this post you will find a curious graph. It shows the behavior of five measurements versus time. "Potential", "Charge", "Current", "Energy", and "Percent". The reason that I said "curious" is that all the raw data were re-scaled so that the min-to-max range of each variable are "normalized" to the range 0.0 to 1.0 (except for the "Percent" variable, since charging here started at 6%).
for any given variable this is done by subtracting the minimum value from the dataset, and then dividing by (max - min), as in:
x' = [ x - min(x) ] / [ max(x) - min(x) ]
Why do things this way? Well, for one, so that all the different variables may be plotted on a single graph running from 0.0 to 1.0.
But more importantly, observing the "shape" of each curve in comparison to others gives you very good physical insight into what is happening under the hood.
A little background in physics:
I Current == Charge/second
Q Charge == Integrate[Current(t), dt] (note this is effectively the same thing as "Amp-hours")
P Power == Voltage*Current
E Energy == Integrate[Power(t), dt]
V Potential (= Battery Voltage)
So from measurements of I(t) and V(t) only - current and voltage, we can use numerical integration to figure out approximate values of Q (charge), and E (energy, or "work" that we put into the battery), starting from only the I(t) and V(t) measurements.
So finally - look at the first JPG image carefully. ("nexus7-2012-Normalized_ChargeCurrentVoltageEnergyPct_vs_Time.jpg")
What you will notice is that three variables: Charge (Q), Energy (E), and Percent all rise quite smoothly in a nearly straight line from 6% to 90% charge state, (or from 0 secs to 9000 secs). So this says that - even though the battery voltage is not smoothly increasing, nor is the current into the battery smoothly decreasing - the charging discipline enforced by the other important chip in the N7 (the SMB347 USB Interface Chip) tries to perform a "constant power input" charging scheme.
A quick diversion: why is the shape of the Energy (E) curve almost identical to the Charge (Q) (or Amp-Hours) curve? It is because of the (apparent) "constant power input" scheme the charger uses: as the battery voltage rises, the amount of current used for charging is adjusted downward. Notice in the graph that even though the "Percent" variable is steadily rising in a straight line, neither the current nor voltage are behaving that way - they are almost inverses of each other so that I(t) * V(t) = Constant.
So - the conclusion, specifically for the N7 hardware - is that "battery percentage" is supposed to represent either Amp-hours input to the battery (charge), or Energy dumped into the battery during charging. For this specific device with it's specific hardware, they happen to be equivalent because of the constant power charging scheme.
Note there are a couple of other interesting tidbits in this graph. The charging cycle spends nearly 25% of the total time charging in the final 90-100% charging range. So if you are carefully watching your tablet charge, it will seem to "slow down" dramatically during that last 10% of charging. (I should also point out that my tablet charges quite a bit faster under normal circumstances - about 2.5 hours instead of 3.5 hours; I believe the script I used prevented the tablet from ever entering deep sleep during charging. A N7 tablet that isn't being held awake with wakelocks should charge in a little over 2.5 hours)
You will also notice that the battery is continuing to charge for about 20 minutes after it reached the "100%" charge state. That's because "100%" doesn't really mean that the battery has stopped charging. In this particular observation, the SMB347 chip was still pushing ~400 mA into the battery after the 100% mark had been reached.
Phew. Finally, I have attached another image ("nexus7-2012-BatteryVoltage_vs_ChargePct.jpg") that shows a display of battery voltage versus percentage charge for two charging cycles and one discharge cycle. Note that when the SMB chip needs to force current into the battery to charge it, it must raise the voltage in order to do that. So it is clear that battery voltage alone can not be used as a proxy for "charge percent", nor can you figure out what the charge is by only looking at battery voltage alone. Not only that, but look at the shape of the curve - it is not a straight line. There is very rapid voltage changes going on at the low end of "% charged" range during charging, very little voltage change occurring in the 90-100% range, and during discharge (red curve) there are are at least 3 different ranges where the slope of the battery voltages change relative to the "% charge" data that the TI chip emits. This is why I suspect that battery apps that only observe voltages probably are not capable of accurately predicting anything other than the ageing algorithms of the BQ27541 chip, and are probably absolutely useless for telling you anything from day to day.
OK, a couple more trivia observations:
- That BQ27541 chip is squirrelly (or perhaps it is the kernel interface, dunno.) There were many sampled data points where the "% charge" reading from the chip suddenly dropped from wherever it had been to *ZERO*. I was sampling the value once every 60 seconds for the data displayed here, but I have also sampled the sysfs (kernel interface) for that chip at much higher speeds, and it frequently produces garbage data. Additionally, the same chip would frequently report *zero current* during discharge condtion - an impossibility. On their website, TI says "Not recommended for new designs". (Usually that is weasel-words that mean "we are aware of some buggy behavior that we are not going to tell you about") Note for instance in the second graph that the battery percentage values 26, 47, 58, 69, 79, and 84% never appear in ANY data set. That means that a battery app - or even an OS "low battery emergency shutdown" trap - could exhibit odd, buggy behavior if they do not use defensive techniques that assume that the data they are getting is partly corrupted. (multiple sample averaging and outlier detection).
- I believe the "sudden steps" in current that I observed during charging (prior post) were real - the tablet had it's WiFi shut off, and the tablet was not in use at all. So while it is certainly possible that random app behavior could have caused some fluctuation in current available to the battery, that would have been much more short lived. Is it possible that the SMB347 chip also has some bugs?
OK, here's the graphs folks. Have fun and good luck with your tablet.
bftb0
Recently i reseted my nexus tablet and found that there was no google earth installed so I downloaded an apk file frm external source and installed google earth from it
but now when i try to uninstall it
There no such button as it shows only disable button
But since it wasn't there before how come now its not uninstalling
N r u using magnetic case .? Is it safe for nexus7?
Like i have heard that it messes with magnetic compass
Plz clear my query.
PROBLEM :-
On Defy Facebook Group --
Many of us are discussing about New/Replaced batteries Reporting Faulty Reading
Mostly all of us Have-- Motorola HF5X -- we don't if they are original OEM or not ---
Battery Charges OK somewhat around 4200 mV , but the problem starts after that , it starts to reduce % by % every Hour on standby .....
Like Just now my Battery is at 3% with 3773 mV , i know it lasts long , yesterday i played Youtube videos over wifi for 2.5 hours on 1% battery:laugh::laugh:,
its all because of faulty reporting , as battery has more Juice as it can been seen by mV.
A workaround has been mentioned by-Condrat Tiberiu
install battery monitor by sim2k from play store and set it to display % based on voltage. for a new battery range is 3150 to 4290mv. but you have to test and see the real range based on when it is fully charged and when it shuts down.
Click to expand...
Click to collapse
But if a Zip could be provided for such problem , We all will be thankful to who so ever help us ....
Thank You
well this is not really a workaround but mostly an add-on. the idea to search for such an app came to me while reading the "defy battery drops explained thread" and it's quite sad that this is the only one of its kind. so all credit goes to sim2k for making such a simple yet effective battery monitor based on voltage that can be used for accurate readings on li-ion batteries. sim2k made that monitor with 3rd party extended batteries in mind but as you can see it can be used for batteries that report fake values (aka cheap chinese clones with emulated controller).
for this to be a real workaround a developer has to figure how to hijack the android battery indicator and make it report % based on a voltage scale that can be manually calibrated for each individual battery and make it report values at a user set interval based on an average of the recorded values in that interval. that way the fluctuations should be reduced. and to make more real there should be some kind of conditions for the % to not go upper than the previous reported values but that will be hard to implement as voltage drops and goes back up based on usage and battery wear.
meanwhile this is the only solution that i can recommend for those who have problems with battery indicator. just install sim2k's battery monitor and learn to ignore the existing one.
if you want accurate reading based on voltage you must set the voltage range for your battery. to set the upper limit you need to charge to 100% (until green led turns on) and see what voltage is reported by the app. that is the voltage corresponding to a full charge and the upper end of the interval. the lower end should be around 3100mv more or less. again if you want to know for sure you have to watch the voltage when the phone turns off due to low battery. but i don't recommend anything lower than 3100 even if phone shuts down at 3000. the point is to have a preventive true 1% warning before the battery drops dead and to give you a little extra time to charge it back in order to prevent damaging the battery due to low voltage. full charge/discharge cycles should be avoided or done once a month at most. so you should charge the battery before it hits 3100mv (true 1%) preferably at true 15% or more. that should prolong the battery longevity and prevent extra wear.
Hey Many thanks that further clearing the things , atm i am using a widget which shows mV plus battery , and i am taking voltage reference for knowing the battery , like u said 3100 + mv time to charge up ,
apart from this issue using slimkat rom and its giving awesome battery backup