Average Battery Life - Nook Touch General

I'm planning on picking up a NST and have had a difficult time finding accounts of what the battery life is like with different usage patterns. I'm particularly interested in writing with an external keyboard but I think it would be a good reference to have a thread where people shared how many hours the battery lasts for depending on what they're doing with it. Has anybody done any sort of benchmarks with full cpu usage or anything like that?

The basic rule is that the Nook has a very long battery life unless it doesn't.
The thing that really kills it currently (so to speak) is using USB host mode.
There is a thread on current drain.
http://forum.xda-developers.com/showthread.php?t=2498187

Related

Can acbPowerMeter be trusted?

Hi!
I have had my Tytn for roughly 2.5 years. This autumn/winter the battery time I could get out of my Tytn was really ridicilousley low, so I bought a new "non original" 1500 mAh battery. It got better but not much, I started to think that perhaps the battery time was never better than this.
The other day I skimmed through this forum about battery problems and found this little program for meassuring battery consumption. I have now had it on since I removed my phone from the charger this morning and now, 4 hours later I'm down to ~30% battery power and acbPowerMeter tells me that the phone has used 90 mAh all together.
I have made 1 shorter phone call and made a couple of synchs with turbo 3G during this period.
Does 90 mAh sound at all right? That would mean that the battery was crap to begin with....or is it possible that acbPowerMeter isn't giving me even "close to correct values"?
Does anyone have any comments or ideas around this issue?
Best Regards,
Olle
Don't know anything about your abcpowermeter. What I do know, is that when I've had a new battery, or when I flash a new ROM, I often have problems with low battery. I just run the battery down like three times in a row, and my battery always improves.
So before making any determinations or using a program, I always run the battery down.
I've got acbpowermeter on my phone, and I don't think it's much good to be honest. If I remember correctly, the last time I left it running, it severely drained my battery - not exactly what you want a power meter app to do.
I find it far more reliable by using BatteryStatus from chi-tai.info and just seeing what the momentary power usage is. (it sits on your Today screen). Yeah, it's not a comprehensive breakdown of your power usage over time, but it doesn't run the battery down like acbPowerMeter does
Like you though, I'm still curious as to what exactly my device consumes in terms of power over the course of a single charge, and I'm on the look out for a decent app which just ticks away in the background measuring power drain...
Hi!
Regardless of Acbpower I just bought a new HTC Original battery and now I have the "normal" battery life I was used to during the first year of my device. As it has allready been discussed in other threads: These non-original batteries are far from always a safe purchase...
Br, Olleman
I recommend Lion Batteries. I have had a great experience with their 3000mAh battery for over a year and a half. Use that 3G on my Hermes and music all the time -- serious user-- and the battery still last me over day. Mind you I am constantly on the internet and always using push email and other data-centric services.
As far as Battery Status, for general purposes is great as I find the more complicated the app the more drain on the system it is trying to read. A simple app that you can just keep an eye over a period of time I think works best.
As far as batteries I was concerned where to buy one. Since my brand new battery died over just a year. Mind you a tethered a lot and I think that tends to kill the battery life faster.

Another battery thread, home screen replacements an issue?!? Poll

Alright, so I've read just about every thread on here about battery life. Some people get 80 hours, other 6. Some people turn the screen on once and the battery is drained, while another person is powering their car with it. Suffice to say, there is a LARGE discrepancy in how much battery we get.
Some thoughts on the subject.
When I first got my phone, battery life wasn't really all that bad. Then I started playing with it. We all rooted our phones. Then we flashed a ROM on there. Then we changed kernals. We updated radios. We installed apps. We took off apps. We used live wallpapers. We changed our screen brightness. We under/overclocked. We also all use different homescreen replacements. And this hasn't really been talked about yet.
So in an effort to get to the bottom of this battery mystery, I'd like this thread to be entirely about homescreen replacements. It's something that's very easy to change and can be measured by each one of us individually.
For simplicities sake, let's do a simple poll on your battery life with whatever home screen you currently use. So we can all measure these the same, let's use the same program. I prefer to use a widget called battery left (find it in the market). I trust this program, as I've seen full day usage anywhere from 30 hours (estimated) down to about 12. When you are fully charged and after a day or two of use, the battery left widget will give you an estimation of how long your battery will last (in hours). So with that information, we can all have our different usage habits, but still compare home screens objectively. For any interested, I'd like to see what different reportings you get from each home screen (but remember, they will require a day or two of usage for the battery to recalibrate. Also, make sure you tell it to recalibrate when you change to a different homescreen).
I think this could be a key area of concern for battery life.
For discussion purposes, I was using Home++ when I was having major battery issues. I have since switched to Helix Launcher 2 and it seems to have improved my battery life a good bit. I do not think I am at the level I was at originally (stock), but I also probably run a lot more. Currently, my full battery life charge with Helix is 21 hours. Battery Left claims moderate accuracy. I will let this run for a few more days and then switch to another home screen and see the differences, while trying to keep my usage habits similar.
I've never once noticed a hit in battery life due to helix launcher2

To ROM or not to ROM

Okay... I've rooted my phone, tweaked a few things (brightness, things that run in the background, etc), removed some bloat (including anything that is location aware) and have my beloved EVO running pretty much exactly as I want.
Here are my current battery use stats:
Cell standby 30%
Phone Idle 30%
CoPilot Live 21% (gps navigation app)
Android System 9%
Voice Calls 7%
Display 3%
1 day 8 hours 10 minutes 4 seconds since unplugged. I have 20% remaining.
No- I'm not kidding.
I've been told that the life I'm seeing is unusual, especially since I use the twitter feed and have a constant Exchange (OWA) push connection and get around 100 emails per day.
Having said all of that - and acknowledging that I'm apparently getting stellar battery life - should I take a chance with a new ROM (eg CM7)?
I'm afraid I'd be committing the proverbial breaking something that's not broken crime.
PS. I have no idea if this contributes to my battery life but I **never** plug it in - anywhere - until my phone is dead. As in shut-itself-off dead.
mybikegoes200 said:
Okay... I've rooted my phone, tweaked a few things (brightness, things that run in the background, etc), removed some bloat (including anything that is location aware) and have my beloved EVO running pretty much exactly as I want.
Here are my current battery use stats:
Cell standby 30%
Phone Idle 30%
CoPilot Live 21% (gps navigation app)
Android System 9%
Voice Calls 7%
Display 3%
1 day 8 hours 10 minutes 4 seconds since unplugged. I have 20% remaining.
No- I'm not kidding.
I've been told that the life I'm seeing is unusual, especially since I use the twitter feed and have a constant Exchange (OWA) push connection and get around 100 emails per day.
Having said all of that - and acknowledging that I'm apparently getting stellar battery life - should I take a chance with a new ROM (eg CM7)?
I'm afraid I'd be committing the proverbial breaking something that's not broken crime.
PS. I have no idea if this contributes to my battery life but I **never** plug it in - anywhere - until my phone is dead. As in shut-itself-off dead.
Click to expand...
Click to collapse
If you create a nandroid of everything, and then move to a different ROM and you want to go back, just restore the nandroid.
That will make it as if you never changed anything, essentially.
Given that type of battery life, do you think it'd be worth it for me, though? From what I understand, a big part of the reason many people flash is to get better battery life... How much better, though, can I really do? And I can't help but worry that all the extra eye candy may come at a cost (as in decreased battery life).
mybikegoes200 said:
Given that type of battery life, do you think it'd be worth it for me, though? From what I understand, a big part of the reason many people flash is to get better battery life... How much better, though, can I really do? And I can't help but worry that all the extra eye candy may come at a cost (as in decreased battery life).
Click to expand...
Click to collapse
As far as better battery life, you're talking about changing kernels moreso than changing ROMs.
If I were you I would just stick to what you have, since you said it's running how you want it.
You can flash different font packs from here:
http://forum.xda-developers.com/showthread.php?t=801160
And different boot animations from here:
http://forum.xda-developers.com/showthread.php?t=708173
That way you can change it to how you want it to look, without messing with ROMs.
I would guess that your battery life is from discharging your battery properly, correct/controlled app background usage, and the way you use your device.
Thank you very much for the clear-cut answer... I think I'll do that - leave it alone.

Battery Life And You: Tips From The Advice Basket

In the DInc forum more than probably any other forum on XDA, there is a copious amount of battery life related threads. How to extend your battery life, what kernel is best, what ROM is best, what extended batteries work, what applications will help, combinations of CPU and brightness, all kinds of jazz. Truth be told, most people who have come to a "solid conclusion" about what is best for their battery life are misleading themselves, and others. Why? Well..
#1. There are too many variables.
Your average joe who posts on here claiming they got XX amount of battery life compared to average joe number two's claim of getting YY hours tells no one anything. The fact of the matter is that in these phones, there are SO many things that act as variables on battery life that most people don't even consider. The obvious ones are data usage, WiFi connectivity, screen brightness, and CPU clocks to name a few. But what a lot of people don't consider are things like signal strength. My battery life personally is bad through the week because my school has absolutely terrible service. My battery life triples throughout the day with Airplane Mode on and WiFi enabled. It's well known in the cell phone consumer society that the better your signal is, the easier your radio will be on your battery. If you're teetering on very poor service, or none at all, your radio is constantly searching for signal so it can get you back on the network as soon as possible. This also applies to the WiFi radio. Some people leave theirs on all the time, some don't. Same for Bluetooth, GPS, anything. There are too many variables for your average person to cover to be able to accurately claim that "this app" or "this ROM" or "this method" does exactly "this" to your battery life.
#2. You're probably undereducated about how your battery works.
Don't get me wrong on this one, we have a lot of very intelligent people here at XDA, many far more intelligent than I, that keep this place rolling on a daily basis, but far too many of the people who try to make factual claims about battery life don't know what they're talking about. The most prolific example of this is the argument between total discharges, and interval charging. There are people who argue that allowing your battery to completely discharge and then charge back to full is the best way to preserve battery life. Then there are some who are adamant about charging whenever a charger is present, regardless of battery percentage. While very few of us here, myself included, are battery technicians or something of the sort, there is factual data to support the idea that Lithium Ion batteries do not have any sort of memory like NiCad and other batteries do. While this may be true, on the other hand, fully charging and discharging your phone allows it to more accurately determine what voltage your battery is producing and thus gives a better percentage reading. Your battery life percentage on your phone is no clear indicator and is nothing more than the phone's mathematical way of processing the output of the battery and translating it into a more useful term for people like you and I. This is why wiping battery stats and completely draining a fully charged battery seems to help with battery life, because you won't see as many violent drops in percentage because the phone can more accurately calculate the power usage. That being said, wiping battery stats does nothing more for you than that. It does not magically make your battery superpowered and won't make dinner for you.
#3. All batteries are different.
Extended batteries are an interesting thing. You can buy two of the same make and model from the same place, and the two batteries can perform completely differently. This is because no two batteries are the same. Quality control issues, differences in materials, shelf life, production date, and all kinds of other factors go into how well a battery will perform. Some people get great experiences from the $10 eBay batteries and some get experiences worse than stock. Some people see quadrupled life out of OEM extended batteries, and some see minimal gains. This also applies to the stock battery that comes with the phone. That being said, mAh ratings are also relative and not all batteries live up to their true claims. A battery said to operate at 2500 mAh may not ever reach that capacity and it may run at a true value of 2000 mAh. The case will rarely ever be reversed, but you see the point. Take battery specifications with a grain of salt, because you aren't always going to get what you pay for.
#4. All phones are different.
The hardware in your phone may or may not be the same as the hardware in my phone, and one of the biggest differences in the DInc with this respect is the SLCD and AMOLED screens. AMOLED screens can save or expel more battery than SLCD screens depending on what you are viewing. A person with an AMOLED who uses primarily dark-themed apps and a dark background may see better life than someone identical who uses light-themed apps and a lighter background. Not to mention that all of the hardware in these phones aren't identical and sometimes parts slip through with lower efficiencies or defects that may or may not affect your battery life, and you will likely never know.
#5. ROMs/Kernels behave erratically.
The Warm Z ROM I use on my phone might deliver totally different results for you than it does for me. Same goes for kernels. We have found time and time again that kernel and ROM changes are not universal for battery life and everybody gets different experiences. You have to try out what fits you, and if you're that interested in finding the perfect balance, you'll just have to try them all. That's a long, painstaking process, but there's no solid evidence to tell you what will be optimal for your setup.
Now...
All that being said, I want you to understand I am not bashing anyone who tries to make a good conclusive result for how to improve battery life. Some methods are common sense and surefire, and some are wives tales. There are some great threads on battery life and topics related to it, two of which I will link to here:
Effects of CPU Frequency and Screen Brightness on Power Consumption
Your Battery Gauge Is Lying To You
These are both by XDA Member byrong, and he uses principles of science and the scientific method to make conclusive data in relation to battery life and how certain variables affect it. He eliminated as many variables as possible in his study and produced linear data that coincides with common sense ideas relating to smartphones and battery life. Note he does not make claims of how long your battery will last, or what kind of effects to expect from each setting, but he produces solid data that allows you to make your own interpretation.
At the end of the day, battery life boils down to balancing out functionality for conservativeness. If you're the kind of person who doesn't need auto sync'ing and push notifications, then by all means disable those things and keep your phone alive a little longer. If you're always by a charger throughout your work day, leave it all on! It's all preference, and there is no solid set method to making your battery all it can be. No ROM, kernel, app, wipe, or other method is going to be the 'be-all-end-all' of battery life extension. Simply see what works for you, and take your own results with a grain of salt. If you test one method one day, and another one the next, and you see that method A gave you 4 more hours than method B, take into account that you were driving through an area with no signal on your way home from work during the usage of method B, or you were playing a game on method B or you did less browsing on method A. Keep your trials as scientific as possible if you want to get real solid results.
Above all, just use your phone and enjoy it. If you never go more than 12 hours without being around a charger, and your phone lasts 15 hours, there's no real purpose in trying to sacrifice more things you use and enjoy to try and get a bigger and better number. Charging a phone, even just a little bit, doesn't take forever, and you can get a valuable amount of juice out of 15 minutes on the plug. Use common sense and don't overthink it. Everybody uses something a little different. That's why we have these phones, because we all want something a little different.
Reserved for future use...
This is great; very informative. Thank you.
Sent from my Magnolia Incredible
Thank you. I plan on updating the second post with a more comprehensive set of links to other articles about battery life that may be found useful.
Cool "A person with an AMOLED who uses primarily dark-themed apps and a dark background may see better life than someone identical who uses light-themed apps and a lighter background"
I guess that's why my phone digs on the Magnolia Rom,
or at least Steves last version it was all black.
Excellent write up. We need more threads like this one by sensible authors who actually take the time to research the topic they are posting about. Thank you for adding knowledge and integrity to this community.
Much love my friend
When I get the chance I'll scour the forums to try and find some more useful threads on battery life and consolidate them here.

Display power usage

Hi,
I recently flashed my G2 to the leaked T-Mobile gingerbread release: so it's not rooted or anything like that. I'm not using it any differently to how I was before.
The upgrade went very smoothly. However, the battery seems to be draining a lot more quickly than prior to the upgrade, and Android's battery usage app points a very damning finger at the display: currently it's showing 67% usage, and pretty consistently shows a high usage most of the day.
Before, I could consistently run the phone for the whole day and charge overnight, but now I'm finding that I have to charge it a bit during the day too in order for it to make it to the night.
I'm pretty sure that I'm not using it any more than usual, and I pretty much always have brightness set to 20%.
So my question is, what could be causing this? Could something be using the screen when it's not supposed to be even though it's not showing anything? Could it be a battery calibration issue? Maybe the power usage app in gingerbread calculates what it attributes power consumption to differently to froyo (though that wouldn't explain the overall reduction in life). What, if anything, could I do to try and track this down further?
Any suggestions would be appreciated!
Some things I should add.
I really haven't changed my behaviour regarding how I use things like wifi, bluetooth and gps. In fact, so far I actually have one fewer gmail account set up on it that before the upgrade, so sync should be doing less work. The apps I'm using are all about the same.
When I said I could use it for the day, I mean it would often end the day with more than 50% battery left. On some days I'd get it down really low, but that would be due to obvious extra usage, which isn't the case here. Occasionally I'd let it die completely. I always charge it fully overnight.
Finally, here are the other top items in my power consumption list at the moment:
Display: 67%
Maps: 8%
Cell standby: 7%
Phone idle: 5%
I seem to remember that before the upgrade, Cell standby and Phone idle were usually the top users of power.
no problem
Sorry, but I don't see any problem. Maybe its just placebo. This is the same on every android based phone. I Had HD2 and had 2 NAND androids till now and the battery stats were showing also display use 60% and then after new NAND version - gingerbread they were up to 80%+ but the battery was better than ever before.
Let me explain it to you. The display should consume most of the battery if you have 3.7 inch display and more. Maybe some navigation and 3G is the biggest sucker like the display but with normal use the Display. And if your display consumes lets say 75% of battery over when you are at 1% battery then it means it sucked 3/4 of your battery and just 25% other things did like phone idle and cell.
If it was before and your display consumed like 40% or less that meant that the other things like cell standby, phone idle consumed more power so it wasnt battery efficient. So its more battery efficient. Maybe you just have much more awake time than you did before. The awake time - sucks the hell of your phone(some apps warn you taht your phone wont turn to the sleep, which means your processor is still working hard which means your battery will deplete completely in a short time)
I experienced this also that my phone lasted only 6 hours or so and before it could wen to all day . Then I deleted some apps which were causing it and my battery was perfect.
and last advice. try to charge your phone via USB, I dont really know why it is caused but it will last longer , but on the other hand you will have to charge it longer. But if you go somewhere where the extra juice is needed then its nice.
With these steps my HD2 with old battery (about 1000mah left on 100%) went through 2 days of medium USE and about 5 days of just receiving calls and messages) so I dont know anyone else who could say that !
ยจ
hope I helped you. GL a HF
If you can stand it, turn the brightness as low as you can handle . EDIT, you're already doing that....hmm
Not sure why gingerbread is giving you problems, personally I find it slightly better with battery than froyo.
Sent from my T-mobile G2
Hmmm... placebo. By that, I presume you mean that since Display is ranking higher in the list now, that's making me think more battery is being used before. I suppose it's possible, but really it's more to do with how often I've been reaching that "I should charge" point, which for me is a function of battery level and time. If I get to 50% before lunch time, I think "I should charge". But getting to 15% just before bed I don't. What I've noticed is that since the upgrade I've reached the "I should charge" point every day.
I'm just very surprised by how the proportions in the battery usage list have changed, while a the same time the phone's battery usage seems to have increased, despite the fact that Gingerbread's battery usage is supposed to be improved.
One other thing that came to mind: perhaps Gingerbread's battery usage is just more accurate than Froyo's? It always seemed to me that the battery level used to work a lot like a car's fuel gauge: it would stick at 100% for a long time and then would drain. It was as though "full" as a concept understood by Android was a range rather than a limit, and so as a result the phone appears to drain more quickly, but it's actually just showing a more accurate battery level over time. Just a theory.
So last night I allowed the phone to completely die. This morning I switched on and immediately checked battery usage: display showing 99%, which is exactly what I'd expect. So I'll see how it goes now that Gingerbread has experienced battery exhaustion.
Personally, if I was upgrading from Froyo to Gingerbread, I'd prefer to start from scratch rather than doing an "in-place upgrade". I'd worry that maybe there are some leftover settings or files from Froyo that could cause unintended consequences. Consider backing up as much data/apps as you can (it's more difficult if you don't have root), charging the battery up to 100%, doing a factory reset, and then restoring and reinstalling everything back. Doing this will also reset Android's battery stats file, so you may find your battery levels maybe inaccurate while it's relearning the right levels for a few days.
Alternatively, if you don't fancy a factory reset just yet, you could try monitoring your power use with a widget like CurrentWidget which looks that the current draw rather than percentages. Also consider installing Watchdog Lite which might be able to help you identify if there are any processes using excessive CPU cycles.
EDIT: Just realised that if you flashed a leaked version, the install would probably have wiped everything anyway, so you can probably disregard the first paragraph.
Like the others have said, I think the screen usage being higher in 2.3 has more to do with the reduced usage of other apps and not the screen using more battery than in 2.2.
Think about it, most of the high battery usage items (web browsing, etc) also keep the screen on at the same time.
Yes, that's probably mostly because other things are using less power. I also suspect that maybe Gingerbread's battery usage app is calculating display usage differently: I just checked it on someone else's G2 (still running Froyo) and Display was way down the list. It dominates mine, even though I haven't used it that much today.
Today's power consumption has been a lot better. It's down to 39% now after 12.5 hours on battery, with 59% of that being attributed to Display. So that's not bad at all really.
Thanks for the tips on the monitoring apps. I'm already using System Panel (which only seems to care about apps and not hardware so much), but it's always worth checking out alternatives.
Couldn't it be due to you being in areas with bad connection?
I noticed that my G2 is down tot 30% after a few hours at school in bad reception+bad wifi areas. When I'm home the whole day my G2 is still at 60% at 10pm.
I have 2 exchange mail accounts set up to push and one gmail account...
Sent from my HTC Vision using XDA App

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