yashsingh1/xdaforums huggingface dataset:
[Android Software/Hacking General [Developers Only]] DarkDvr:
Yep, the dude that spoke on the conference about battery life said that although WiFi uses more battery than 3G, it takes a lot less time for it to download/process data, and then go to "sleep" of sorts. So, over a period of time, WiFi would "sleep" more than 3G, which makes it far more efficient.

I always use WiFi whenever I can (at home for example).
[Android Software/Hacking General [Developers Only]] RaduX1:
+1 ... and thanx for the chart.
[Android Software/Hacking General [Developers Only]] Macmee:
I didn't charge my battery all the way up before using my N1 (though I did leave it plugged in when I was using it). Was that bad for the battery?
[Android Software/Hacking General [Developers Only]] RogerPodacter:
I think of it this way, WiFi only needs enough transmit power to broadcast a couple hundred feet. 3g needs power to transmit a couple miles or more. which one seems like it would use less power? I say WiFi.
[Android Software/Hacking General [Developers Only]] Macmee:
There's no such thing as public wifi here, I'm lucky to get a signal anyways.

Here's from thismorning, no use:
[Android Software/Hacking General [Developers Only]] DarkDvr:
Nah, not really. It is recommended, but it seems that nobody can tell for sure what kind of impact it has. In my experience, I have 2 batteries - one I broke in, one I used right away... It seems that I do get a bit better battery life with the one I've broken in..
[Android Software/Hacking General [Developers Only]] Paul22000:
For optimal battery performance:

If you're going to be at the same place for a long time (ie at home or work for 8 or more hours), do you leave it plugged in, or charge to 100 and immediately unplug?

If unplug, how low do you let it go before plugging back in? 90%? 80? 40?
[Android Software/Hacking General [Developers Only]] DarkDvr:
For 8 hours it doesn't matter that much, but I'd charge it, then let it discharge on it's own. Depending on my plans for the phone that day, I'd connect it back to charge around 60-80%.

When they say «long term» they are taking about months, not hours.
[Android Software/Hacking General [Developers Only]] Paul22000:
Yes, but when you're doing the same method for 8+ hours every day for 3 years, it's the same thing, hence my question of which method is better :)
[Android Software/Hacking General [Developers Only]] quahog_convo:
Really really informative post. Thanks.
[Android Software/Hacking General [Developers Only]] JHaste:
so i finally got my car dock and the phone got absolutely roasted sitting in that thing while the sun was beating on the windshield... not good huh? should i look to put it in the path of one of the air conditioning vents then?
[Android Software/Hacking General [Developers Only]] DarkDvr:
Yeah that's the problem that I have too.. Do you have the google official dock? It's a but more enclosed, dunno if that helps our makes it worse....
[Android Software/Hacking General [Developers Only]] DocSnyd3r:
Wow so EDGE uses more energy than 3G I tought it was the other way round.
[Android Software/Hacking General [Developers Only]] RogerPodacter:
i thought it was the other way around too, and i'm not sure i believe what is said no matter what. when i use EDGE my phone lasts twice as long as when using 3G. so to me i think that the air interface of GSM/EDGE is just more efficient than WCDMA. that's my theory and i'm sticking to it!
[Android Software/Hacking General [Developers Only]] JHaste:
lol yes i do and let me tell you driving back from vegas to phoenix, the thing could have cooked eggs on the back of it... i would have priced the back of the phone at sitting around 50-60C?:eek:
[Android Software/Hacking General [Developers Only]] DarkDvr:
How about the phone itself? I don't care how hot the dock gets if it protects the phone from heat (by means of no direct sunlight on the nexus). I'm considering buying the dock from google, but only if it can be used for driving during the day in the sun...
[Android Software/Hacking General [Developers Only]] uansari1:
Great thread. I remember learning a lot of this information, from the same website, back when I frequented the T-mo Dash forum.

By the way... best way to store batteries, as that graph implies, is around a 40% charge in the fridge. I have my backup phone's battery in there right now... take it out every 4-5 months, charge it to full and run it down to 40% again before throwing it back in the fridge. ;) It's battery life has remained excellent since I've been doing this from early 2008.
[Android Software/Hacking General [Developers Only]] ChillRays:
I love the guide Darkdvr, you did a great job. I wish you would take this just one more step further and post info such as how much battery is used up when certain functions are running. Such as GPS, Navagation and then some. I'm driving from tampa to atlanta next month.. I dont have the money for an extra battery and i'm just wondering if I can make it before my phone dies. I'll bring a car charger just in case but you know. Thanks if you could put together something like that.
[Android Software/Hacking General [Developers Only]] Paul22000:
What is the optimal charge cycle length?

ie Are two 75 to 100% cycles better than one 50 to 100%?
[Android Software/Hacking General [Developers Only]] DarkDvr:
Thanks =)

Yeah, that's a great idea. If I'll find the time, I'll cycle my N1 through some tests and post them here.
[Android Software/Hacking General [Developers Only]] DarkDvr:
Well, it's not as precise, but they are suggesting that short charge cycles about 40 to 90 or so percent are probably the best. Also, those charges, in the perfect world, would be made with a trickle charge, like a USB charge.

Keep in mind, that no matter how "good" you are to your LIB, it will die in about a year anyway (YMMV). So there's no need to worry about that too much. Just keep it cool whenever possible and don't let it die to 0% (aside from the calibration cycle every 30 charges or so).
[Android Software/Hacking General [Developers Only]] bmszabo:
What is your advice for "CPU profiling app to monitor the CPU"? I assume there are couple of them on the Market, which is the best to monitor the CPU use?
[Android Software/Hacking General [Developers Only]] Marine6680:
2.4v may technically be safe, but 2.9-3v is a much safer voltage for prolonging battery life. Most battery makers use that discharge voltage for calculating battery capacity. Best thing to remember with Lion batteries is to avoid the extremes of its capabilities. (IE charge rates, max discharge)

I don't know if anyone mentioned this, but a phone has a minimum operating voltage. I think the G1 was around 3v. So the battery bar percentage uses that voltage as its 0% level. So you will not be using all of the available capacity of a battery if the lowest voltage the device can operate at is any higher than 2.9v or so.
[Android Software/Hacking General [Developers Only]] DarkDvr:
I use the one that's called "CPU Usage".

Just don't use any with widgets, as profiling CPU use is consuming CPU cycles (quite a bit, surprisingly), and often widgets would wakelock the CPU to 100%. That'll kill the battery.

So I launch it, check the usage, then kill it.
[Android Software/Hacking General [Developers Only]] zippa71385:
very interesting... I never charge over night and only charge about 2 hours a day... depending on how much im on the phone the day before it doesnt get 100% charge... Is that bad?
[Android Software/Hacking General [Developers Only]] flarbear:
No, but the battery meter may read conservatively if you don't allow it to discharge all the way and charge it back up full periodically.

If the protection/meter circuits in the power circuitry never visit the ends of the battery's charge spectrum they have to guess where they are and they usually guess conservatively so that they don't risk overcharging or overdissipating the battery (both of which would be bad for a Li-Ion battery).

If you never seem to reach the empty end of your battery meter then it won't really harm you. But if you start thinking your battery isn't lasting very long, try a calibration charge to see if that restores the estimated run-time. A calibration charge involves discharging until the phone turns itself off, then recharging until the phone says it isn't charging at all any more. Voila - now your meter should be fairly accurate. Sometimes when the estimates were way out of calibration you might need to do a couple of calibration charges to get it to the max state.

Note that a full discharge and recharge on a recently calibrated battery goes a little faster since the phone can approach both ends of the spectrum with relative certainty. If the battery is way out of calibration then it may post warnings and do its first "automatic power down" prematurely when there is still usable juice left in the battery. Similarly if it isn't sure where "full" is then it may slow to a trickle charge well before the battery is full and then it will take many hours longer to fill the battery as it slowly creeps fearfully towards the true full state.
[Android Software/Hacking General [Developers Only]] johanove:
Great information, thank you!!

I can recommend OSMonitor for watching your CPU load and whats causing it.
[Android Software/Hacking General [Developers Only]] DarkDvr:
Thanks for the recommendation, OSMonitor is indeed great for that.

I've added this info to the first post.
[Android Software/Hacking General [Developers Only]] zedmec:
I have a spare battery, when it is not in use, should I store in fridge or at room temp

great info
[Android Software/Hacking General [Developers Only]] scotchua:
Very nice, well written and informative article. There's always a lot of debate about battery life and it's nice to have somewhere to point people with lots of questions.
[Android Software/Hacking General [Developers Only]] victorhooi:
heya,

I bought a Nexus One on eBay (it's not available in Australia yet).

I'm not sure how much it was used before I got it, however I did do a full drain/recharge the other day.

However, it's interesting the point above about how if it hasn't been recalibrated recently, how you might need to turn it back on again, and see if it's really drained, and repeat. Seems a bit annoying - and how do you know when it's really drained? Any experiences?

Also, I tend to keep it plugged into a AC-to-USB charger on my desk when I'm at work, so it stays fairly close to 100% - I assume the Nexus hardware is smart enough to just shut it down when it's at 100%. However, is this bad for the LiOn cell?

From the above, it seems to suggest you should charge it, let it drain to around 40%, and let it charge again.

Is that better than just leaving it plugged into the charger a lot?

Cheers,

Victor
[Android Software/Hacking General [Developers Only]] DarkDvr:
Not sure what you mean, by calibrating it should be done every 30 or so days/charges, and the way you calibrate it is to drain it fully (keep turning the phone on after it's "dead" until it doesn't turn on anymore) and then charge it to 100%.

nah, it's fine. It is smart enough to stop it, but it's not done by Nexus. LIBs have built-in hardware to disconnect charging at 100%. If LIB wouldn't do that, it'd explode. So don't worry.

in a perfect world, yeah. However, idea with LIBs is to "use it before you lose it". Only thing you should worry about is draining it fully (unless u're calibrating).

A little, but it wont make a difference. As long as it doesn't get hot for long periods of time (i.e. if ur charger makes battery hot), its ok.
[Android Software/Hacking General [Developers Only]] RogerPodacter:
i've noticed that claibrating it once every 30 days does absolutely nothing. once you do that first charge when the phone is brand new, in a way you are stuck with that meter calibration. when i first charged my nexus brand new, it died at 8% and would never go down to 0%.

ever since then, i always dies at 8% no matter how many times i try to "re-calibrate" the battery meter. the only way to do it is go into recovery mode and wipe the battery log file and start over.
[Android Software/Hacking General [Developers Only]] DarkDvr:
It does do something, LIBs have internal gauges that benefit from cycling, which allows them to better "know" where the "empty" point is.

The "empty" point of the battery is handled by the LIB, not by nexus. LIB tells nexus its charge level and when it's empty. Specifically, when booted up, nexus reads the level from LIB, and if it's below X%, it will turn off.

And it's very weird that your battery dies at 8%. Mine goes down to like 2-3%, dies.. and then I can still boot up Nexus into OS several more times, until there's just no battery left to even respond to the "power button" push.

Dude, it's something with your phone itself. At 8%, mine's complaining and flashing red, but still works.
[Android Software/Hacking General [Developers Only]] mtw4991:
I tried to calibrate yesterday like you said, the phone shut itself off when OS Monitor said 13% left. I fully charged via wall charge, discharged fully again and it shut off at 6% left. Another cycle and again it shut off at 6%. Each time I wiped Battery Stats, which now seems to have been the wrong procedure!

I didn't try to restart it several times like you suggested to fully drain it, so I will test that by recylcing til off, then reboot until nothing left, charge fully without wiping Batt Stats and report.
[Android Software/Hacking General [Developers Only]] thedsp:
Swapping batteries

If I understand correctly, gauging and management of the battery is done 100% in the battery itself? So swapping batteries should not "confuse" the phone?

I remember years ago, with my notebook it was an issue, when I used 2 batteries and exchanged then. The software couldn't handle the two different pieces and got confused..
[Android Software/Hacking General [Developers Only]] stuff:
You should wipe the battery stats on your N1 via recovery. Perhaps that will fix it.

My phone doesn't shut off until I see 1% remaining. Then I can boot it up once more then it'll be dead completely.
[Android Software/Hacking General [Developers Only]] RogerPodacter:
can i just wipe the battery stats from recovery easily? i dont have to do anything special for this process?
[Android Software/Hacking General [Developers Only]] RogerPodacter:
Well I did end up wiping my battery stats and it STILL dies at 8%no matter what I do. All I can conclude is via. Each battery has a manufacturing variance, and mine is slightly lower than what the OS's hard coded calibration meter is expecting, so its always about 10% off.

Similarly, when I do a full charge to 100% my phone reaches 90%, shows 4.172 volts (which is full), then skips right from 90 to 100% in an instant. It's like the entire battery meter is offset by 10%. No matter how much I wipe the stats and fully charge then discharge, this still happens.

Must just have a weak battery out of the box. But this tells me the OS has a pre-loadsknown battery meter, and no matter what you do it is using that meter. So "calibration" is pointless as the phone has hard coded battery range voltage and info preset and we can't change or calibrate that range.
[Android Software/Hacking General [Developers Only]] TimTim12:
Great stuff, I bought my Nexus One used and I think the previous owners were pretty bad about charging it, it seems to die within 3 or 4 hours of heavy use. I rooted the phone and installed advanced task manager, setcpu, and juicedefender along with conditioning the battery and it seems like the battery life has improved quite a lot. Usually a full charge and going to sleep would drain about 15 percent of the charge (sleeping eight hours) and with the new set up it loses about 5 percent of the charge. I think it's tolerable and I'll just wait until a year or so to buy a new battery.
[Android Software/Hacking General [Developers Only]] DarkDvr:
My personal testing tells me this:

- don't use task managers at all. Android handles task killing very well

- don't use juicedefender or setCPU. They don't do anything that Android doesn't already. They just use up space in ur ram.

- FRF82 and later has some tweaks that improve battery life significantly (many people confirmed that). I used to get 12 hours, how I get about 25-26 hours on 1 charge.

-Charging the battery while it's not in use seems to be better (like charging it on a dockm separately from the phone, or when phone is off)

- Dark wallpaper (a darker ui) will reduce display power drain a bit (you can see the difference in % in battery use stats)

- Live wallpaper drains battery a little, but not much

- Installing OSMonitor is helpful, if you're thinking that some dumbass app is using wakelock to keep your cpu running, OSMonitor will show you that (free on the market). Just don't forget to exit OSMonitor when u're done, so that it doesnt keep profiling your CPU/mem usage.
[Android Software/Hacking General [Developers Only]] Wam7:
I was just about to get a charger for a Nexus and was tempted to buy a 1200mAh over a

1000mAh one but on doing some research it seems that getting a 900mAh one will prolong the battery life. How long would it take a 500 mAh charger to fully charge the phone?
[Android Software/Hacking General [Developers Only]] android01:
For me its about 2 hours at 900 and 5 hours at 500
[Android Software/Hacking General [Developers Only]] murules:
This thread has been very helpful, thanks!

I currently use my phone until it is about 20%, then charge it overnight. So ideally really what I should do is let it go to 40%, then charge it up in the evening using a USB charger to what percentage? And then every 30 or so charges let it go as empty as it will (by switching the phone on again when it automatically turns itself off until it won't go on anymore) and then charge it to 100% and it says it isn't charging anymore.

I'm guessing this the same for laptop batteries? Ie I shouldn't let it go to empty every time I unplug it and shouldn't leave it plugged in 24/7 the rest of the time, but should let it go to 40%, then recharge to near 100%, then unplug to 40% again, then recharge?

Thanks for your super help!
[Android Software/Hacking General [Developers Only]] DarkDvr:
The thing with LIBs is that you don't really have to worry too much about them. What I mean is that whether you neglect them and use them like you stole them, or you treat them like your firstborn, they will still die in a couple of years. If you want to never let it go lower than 40%, that's fine, but you need to know that you aren't winning much overall life for your LIB.

After doing the research what I do is change battery/plug in when Nexus complains about low battery (15%) and I drain the battery every month or so.

Since I got 2 batteries (one in dock, one in phone), I switch them every several days.

Just remember that no matter how well you treat it, it'll die regardless. It's like a sick hamster :D
[Android Software/Hacking General [Developers Only]] Kevin2011:
I would like to appreciate the work of blog author that the person provided us with an extremely excellent information regarding the topic. Ireally learned something from this blog and started to contribute my ideas via commenting on this blog. Keep it up.:)
[Android Software/Hacking General [Developers Only]] RogerPodacter:
this is an old thread:). but we found out that wiping battery stats really doesnt do anything, it is just an internal battery file. we finally hacked the chip inside the battery and are able to do some great stuff with it. check the link in my sig for the app and thread about it.
[Android Software/Hacking General [Developers Only]] utalok:
Thank you! I can take care my batteries better in the future thanks to you.
[Android Software/Hacking General [Developers Only]] Martezgarki:
I have a question here... is it important to charge it to 100% everytime you charge your phone? You do realise that sometime you're in a hurry and you won't have that 2-3 hours to charge it fully right?
[Android Software/Hacking General [Developers Only]] DarkDvr:
Nah, it's not important. Every once in a while you do want to charge it to 100%, probably when you're cycling the battery every 30 or so charges.

Otherwise - don't worry about charging to 100%.
[Android Software/Hacking General [Developers Only]] ssaigol:
I would like to throw in my 2 pennies here. As a radio control aeromodeller who flies electric powered planes it has been my experience that Li-ion and Li-po batteries do not like extremes. They are designed for a max voltage of 4.2 (plus/minus 0.05 volts) volts and a shutdown voltage of 3.3 volts. This does not mean that you have to charge them to max every time. In fact you will see that your phone will show full charge in the notification bar and the message light will go continuous green when your phone reaches 90 to 92%. That is good enough. Charging to max voltage every time reduces battery life.

A widget which shows voltage as well as percentage is recommended.

Use the original supplied charger whenever possible. Use the original USB cord when charging from USB port. Your phone will slow charge at half rate from USB and with a car charger. That is not a malfunction, its is designed that way to allow the phone to be connected for long periods.

Never buy bargain basement replacement batteries, they will underperform, malfunction and can be dangerous. Buy replacements from reputable suppliers not ebay fly-by-nighters.

I am a new owner of a Huawei Ideos U8150, my first Android phone.
[Android Software/Hacking General [Developers Only]] nuteam:
thanks, very useful!
[Android Software/Hacking General [Developers Only]] DCMAKER:
li-ion batteries are not exactly partial to partial discharges. You will get the same wear from a 100% drain and 4x25% drains. Also you forgot to put LiCoO2 cells can get an easy 300+ full discharge/charge cycles before they reach 80% capacity. So if you leave a battery at 100% charge for a whole year it gets the same amount of wear if you use it everyday for a year...appropriately the same wear. So realistically there is no point in doing anything different than you normally would unless you plan on not using a battery for more than a month.

also here is a great site for DIYs and battery info to double check your info...also there are many different kinda of li-ion cells you should be aware of

http://www.batteryspace.com/li-ionsinglecell.aspx

EDIT: also your basically bound to loose 20% capacity in a year no matter what you do. so doing full/partial or whatever is not going to get you any more battery life....not enough for it to matter. Also all those li-ion tests pertain to LiCoO2 cells i believe. So if you build a battery using LiFePO2 cells i dont know if those wear and tear charts matter. Reason being LiFePO2 cells get 2,000 charges before they hit 80% capacity and i have not seen any data on tests regarding those cells. So that would be a good question to email to battery space asking them if they know anything about LiFePO2 battery degrading over time.
[Android Software/Hacking General [Developers Only]] Desert Storm:
Thank you, very nice - easy to understand guide.