yashsingh1/xdaforums huggingface dataset:
[Nexus 9 General] darkchazz:
Alright I think it's time to share my results on battery life:

8 hours SOT with 21% remaining.

The gap in the middle is when I rebooted my device.

Usage was lots and lots of PDF and slides, some web browsing, and a couple minutes of Hitman GO and MegaN64 emulator.

My tips on improving battery life and reducing heat. *root required* :

1) Modify the CPU governor and min frequency - I used trickstermod app

I've no idea why google set the minimum CPU frequency to 500MHz... Could be the Denver cores are more efficient this way.. Or not...

I've set mine to 230MHz as lower frequency should theoretically improve idle battery life..

Next is the governor.

-Why in the world is the input-boost frequency at 1.5GHz ? Denver has a very high performance per MHz which mean you don't need that much freq to drive the UI.

I've set mine to 1GHz and the UI is still as smooth as it was before. That's an easy free battery time and less heat.

-Another thing I did is increasing the frequency threshold as I don't want the CPU to jump to very high frequencies unless the load is very high

I modified the target_loads parameter to "85 1530000:90 2014500:95"

2) Block Ads NOW !

Use Adaway. Found here: http://xdaforums.com/showthread.php?t=2190753

The Tegra K1 produces much heat and battery drain when pushed to high frequencies, and that's exactly what Ads are doing.

The processor is pushed even if you are sitting idle on a page!

Here is a comparison on Androidcentral. Both on idle after the page had fully loaded:

The more Ads, the more dramatic the effect is. Ad heavy pages can cause the CPU to jump to 2GHz+

Blocking Ads not only fixes all that, but makes scrolling smoother.

That's all I can provide for now.

Thanks!
[Nexus 9 General] Hiro Nakamura:
Yes the Cpu is working very inefficient by default and Ads are always very annoying haha :p

Maybe you want to lower the boostpulse_duration to something like 1 second or lower too. Also the minimum freq rated for denver is 204mhz i believe if you want the lowest.

As always lowering screen brightness helps a lot too.
[Nexus 9 General] Semantics:
Got mine last night, charged it full, has pretty bad QC issues so it's going back, but I have noticed that the battery is draining quickly while the tablet is idle. Went from 100% to 93% in 16 mins. I've installed nothing but GSAM battery monitor on the tablet, bootloader locked and bone stock. If I use the tablet, I lose about 1% every 8-10 mins. Not sure if this tablet is a dud, but the battery has been pretty awful.
[Nexus 9 General] mk92595:
One word: calibration
[Nexus 9 General] Chyeo1979:
Huh, your tablet drains about 1% every 2.5 mins when idle, but drains only 1% every 8-10 mins when used?? How can it be?

*1% every 8-10 mins is really good battery life anyway
[Nexus 9 General] Semantics:
I honestly don't know what's going on. It appears it wasn't sleeping at all. I've sent it back to HTC US for repairs on the screen and buttons, I'd rather not play the lottery game with Best Buy, so if they fix it, great, if not I'll just refund it. I can't play with it obviously to see what was going on with it, but I found the battery stats really bizarre.
[Nexus 9 General] nemonius:
http://www.phonearena.com/reviews/Google-Nexus-9-Review_id3842/page/4

"In our real word experience, it’s able to propel us through 1.5 days of power usage – a mark that we feel is commendable on many levels. Even better, though, is how it performs in our very own standardized battery benchmark test. Producing a mark of 9 hours and 24 minutes, that nearly matches Google’s claim of 9.5 hours of juice with Wi-Fi browsing. Worthy of being noted, too, is that the mark eclipses its rivals in the iPad Air 2, Xperia Z2 Tablet, and Galaxy Tab S 8.4!"

They liked it performance.
[Nexus 9 General] Sean09:
This is my second full charge from 100%. Screenshot below, unplugged at 6:45AM~. 5H10M of screen on time. Conducted various activities such as web browsing, PvZ2 (playing and leaving idle, both caused minor heat on the tablet), and streaming youtube. Brightness was just below 50%. Ended the test at 20% remaining.

6:45AM - unplugged.

9:00AM - 91%

10:15AM - 77%

11:17AM - 55% (started youtube stream)

11:51AM - 46%

12:26PM - 40%

1:46PM - 28%

2:40PM - 20% - test concluded, 5H10M SOT
[Nexus 9 General] LinS123:
Currently in the middle of a battery test. I'm literally playing a movie, in this case How to Train Your Dragon 2 (1080p AAC2, 3.5GB), on repeat until the battery decides to give and time it. Hopefully this will give me a general gist of how long the Nexus 9 lasts as a media tablet.

45%-ish brightness, Wi-Fi on (connected to 5GHz network), Bluetooth off, Location on.
[Nexus 9 General] pantmunu:
I actually took that as a compliment. Thanks.
[Nexus 9 General] username4this:
Hit the thanks button then.

On a serious note, I just reread my post and I sounded like a prick so for that I apologize.

My opinion remains, embarassing battery performance for something that advertised a 20 to 25% gain over KK.
[Nexus 9 General] pantmunu:
No .

I'm getting a pretty decent battery life . and I am happy with it.
[Nexus 9 General] username4this:
You're not, and I'm sorry to disapoint you, lying to yourself as much as you want won't change that.

With normal to moderate use, the battery performance is horrible. Doing nothing and getting 5 to 7h of SoT is terrible and makes me feel random shame about other people.

Is it because of Lolipop not being optimised still? Or most of the apps? Heating taking performance away? CPU too power hungry?

I don't know, but battery sucks and it sucks specially when Google claimed Lolipop would bring many improvents over KK.

For future reference, I'm not expecting a "brand new" OS to perform flawlessly out of the box but for 400€ I sure as hell would expect a tablet such as this to perform, and atm, it's just been a disapointment.
[Nexus 9 General] pantmunu:
OK heres the thing .. " I'm happy with my battery life" means I am happy with it .. Either if its worse or if its awesome . its up to me to decide if the device I own has a good battery life for me or not . I am not disappointed whereas in your case you are . two different scenarios. I don't need to lie to my self . I am constantly watching Netflix YouTube ... Using MX player and browsing chrome .. XDA ... Been using Instagram Facebook a lot and got around 4 and half hrs of sot last night with 10 % remaining. And I am happy with it . that's what I was trying to say.
[Nexus 9 General] Gormsen:
Unfortunately I agree with you, I can't seem to figure out why the tablet eats through the battery so fast. I know that it has almost twice the screen size of the Nexus 5 and is pushing a lot more pixels, but the battery is almost three times the capacity of the Nexus 5, so it really should last much longer than it does now.. Could be that it's not optimized, and I sure do hope that Google is looking into this.. Wonder if custom kennels can do anything about this?

Smashed down on the mighty Nexus 9
[Nexus 9 General] jaju123:
Idle battery life seems very nice, and video isn't so bad either. It's just CPU intensive stuff that really causes the drain, as can be evidenced when web browsing or using non 3d apps
[Nexus 9 General] Gormsen:
Chrome really makes the N9 work for its money.. Haven't noticed that on any other device, could it be that it's badly optimized for 64 bit?

Smashed down on the mighty Nexus 9
[Nexus 9 General] USBhost:
get adaway

that fixed all my problems with my Chrome
[Nexus 9 General] Gormsen:
I don't think it's just the ads that's pushing the cpu. Like I said I never had a problem with it on other devices, but this device rapes my battery, when just reading on webpages..

Smashed down on the mighty Nexus 9
[Nexus 9 General] USBhost:
Also the cpu governor needs some 2 tweeks

If you really want good battery

Set it to on demand
[Nexus 9 General] Gormsen:
I thought Google had abandoned Ondemand in favor of interactive, which should bring better performance and battery? (I know about the difference between the governors) how are you experiencing Ondemand, is it just as smooth, better battery?

Smashed down on the mighty Nexus 9
[Nexus 9 General] USBhost:
Well its ok

But it acts like battery saver

You will get lag

so no its not smooth
[Nexus 9 General] Gormsen:
Well.. That's a bummer.. Think I'm going with the battery saver for now..

Smashed down on the mighty Nexus 9
[Nexus 9 General] USBhost:
Or you can set your max cpu speed to like idk 1Ghz/1.3Ghz
[Nexus 9 General] Gormsen:
I could, but wouldn't that cause it to lag too? Haven't installed any CPU monitoring apps yet, so don't know which frequencies it uses the most.

Smashed down on the mighty Nexus 9
[Nexus 9 General] USBhost:
maybe but it will do better than on demand

1. 0.5Ghz

2. 1.5Ghz

3. 2.3Ghz
[Nexus 9 General] Apoxx:
I get around 4 hours of screen on time. Not impressed at all.

Returning mine. Just too many issues.
[Nexus 9 General] singmokjai:
Nexus 9

Mine arrived on the evening of 12/12/14 with about 40-45% battery. Had it on for 4 hours and turned off the tablet for the night with about 38% battery. Woke up this morning and turned it on this morning until now. I left it on but I didn't use it the whole time. I just simply turned off the screen if I wasn't using it or if I was stepping out. Currently it's at 16% after I downloaded some apps and did some light browsing. Pretty impressed so far considering I haven't even gone through my first charging cycle or in this case I haven't even charged it yet since it arrived lol.
[Nexus 9 General] ram130:
On the other side of the pond I'd be at 30% on that first charge.

You just don't know what good battery life is for a tablet yet. :/
[Nexus 9 General] USBhost:
So whats good battery?
[Nexus 9 General] brushrop03:
I wouldnt entertain this guy.
[Nexus 9 General] FrankBullitt:
Why? He even told you what a good battery behavior/consumption would be, and he is absolutely right. I've had an iPad and the battery consumption on any regular task (web browsing, gaming, even idle consumption) is not even comparable. If you've never used one before you don't understand what he's trying to say.

People here get so uptight whenever their beloved Nexus gets criticized that it starts to look like I'm on a iOS forum asking for help about something...
[Nexus 9 General] brushrop03:
Not getting uptight. Just this guy has been saying the same thing for weeks. Tired of his constant complaining. If not happy return it. My experience is completely different. I get great battery life (6-8hrs). And battery life isnt everything for everyone. I would give up a little battery to avoid ios
[Nexus 9 General] FrankBullitt:
Battery life is not the most important thing for everyone, you are right, but you cannot say you have great battery life because you get 6-8 hours of SOT. That is not great battery life, that is average at best and I guess that's what he is trying to say (and I agree).

If its enough for you, good, I have no issues with that, but for a WiFi only tablet it is not a good measure at all, specially if you come from an iOS device.

BTW, I was once happy with battery life but then things quickly degraded. The way the background tasks are managed is terrible and that causes the idle consumption to be worse than in my N4 running the same L build. Something is very broken in the 64bit experiment so far :/
[Nexus 9 General] singmokjai:
Nexus 9

I guess what I tried to say was with my nexus on idle consumption, battery life so far seems great. I haven't really worked it yet so I guess I will know after the first charging cycle. I'm putting it to charge now, what's the avg charge time for everyone?
[Nexus 9 General] DaMan:
Finally "fixed" the heating issue on my N9. I bought it yesterday and it was heating like crazy when browsing with Dolphin. It was getting around 160F.

Only thing is i disabled javascript and now after 25 minuters of browsing temp is around 100F. Not ideal without javascript but it's easy to enable.

Will see when google comes wiht a real fix.
[Nexus 9 General] FrankBullitt:
The charger that comes with the box has a very low output, so it will charge very slowly. A full charge may take 8 to 10 hours. You can use another charger with a higher amp output to make the charge faster. I use a 5V, 2.0A and I can fully charge it durig my 5/6 hours sleep at night (it should take less than that, but I'm asleep so I don't know exactly, ahah ).
[Nexus 9 General] USBhost:
The kernel limits the charging output

To 1.5a

Using a 2.0a charger would do no difference

unless the kernel supports it
[Nexus 9 General] Gormsen:
I can fully charge mine in 4 hours, and as Usbhost said, there's a limit in the kernel to 1.5A, so it doesn't matter if you use a 4.7A charger, it would still only take in 1.5A.

Smashed down on the mighty Nexus 9
[Nexus 9 General] FrankBullitt:
The HTC charger that came with mine is a 0.8A. (It's absurd). I use the 2.0A by commodity (i had it spare).
[Nexus 9 General] USBhost:
What!!?!?!

A 0.8a one Huh???

I got a 1.5a with my nexus 9
[Nexus 9 General] FrankBullitt:
Yeah, I don't remember my first N9 charger rate, but this replacement one is a 0.8. If you search this forum first threads you'll see many were complaining about slow rates due to the charger being a "phone" one. Maybe it was a batch of devices being bundled with this charger, not sure...
[Nexus 9 General] darkchazz:
Newest cycle
[Nexus 9 General] darkchazz:
Check post #375
[Nexus 9 General] Chyeo1979:
What do you mainly use it on? Dun seem to be using any app heavily. Can you try one mainly using chrome all the way?
[Nexus 9 General] ElementalXY:
What's your idle time?
[Nexus 9 General] darkchazz:
I haven't charged the device yet.

The current idle time is 4 days & 47 mins, with 8% battery remaining.
[Nexus 9 General] jsgiv:
I really don't get these stats of people quoting great battery life.. Yet they show 1-5% usage of an actual application during the same time...

It's great you got 10 hours of SOT ... But what were you *doing* with the tablet for 10 hours? You don't have any app usage over 1% ... So what did you do with the tablet?

Mine got "ok" SOT depending on the application being used.. However anyone getting actual usage of more than 6 hours of actually using the tablet I'd question... I use my tablets to browse constantly throughout the day ... I was lucky to get close to 5 hours SOT on the Nexus 9 before having to charge... By comparison - many of my other tablets last much longer...

Show me a SOT of 10 hours with 20-30% chrome usage and I'll be impressed.
[Nexus 9 General] ram130:
Agreed. Yes exactly. Thanks.

Honestly I've been a Nexus user for a while. Before that I had an iPhone for 3 yrs. Before that a G1, N1, Droid X and so on. To me battery life sucked at times on the iPhone. I became unhappy eventually especially with the OS. I'm not afraid to call things out. I only got an iPad literally 3 weeks ago. Only to test things out and see if it's any better. I ended up liking it and willing to work with the disadvantages. My biggest being how notifications are handled, scrolling speed, text selections, sharing system and navigation. At times it feels backwards in other ways. But again the positives so far have won me over. Enough to not regret it. Especially at $350 for 32GB with a student discount. Something Google should consider.

As for the N9. I just had it with Google and calling them out for it. This tablet is so close to great. But now it's mainly good. Closer to OK. For $500 we all expected better. I was even expecting great sounding speakers, but nope. Performance a mix bag instead consistent kind of hurt me too. I also wanted a bigger screen from my N7 and no screen issues(had annoying touch issues on the N7). I pulled trigger instantly. Every time I come back to using it I'm reminded why I love Android and why I don't like the N9 itself. Overall I now feel I'll be fine waiting for a better version of this for a year. I'm returning it. The Mini 2 and my N7 should keep me content for now. I'll keep missing this tablet though.

Now that's amazing. If I got that with regular use out of the box I'd be happy. That's what I'm getting on my Mini 2.
[Nexus 9 General] Semantics:
Is it amazing, though? The app he used most was Chrome and it came in at a whopping 1% of the usage. For all we know, the tablet sat on a table with brightness all the way down for 10 hours. There was no real usage on that tablet.
[Nexus 9 General] ram130:
Well I was mainly referring to in general and if it was regular usage. Then amazing.

Though for me..
[Nexus 9 General] Semantics:
That pretty much mirrors my battery. I don't see anyone who really uses the tablet getting 10 hours of SoT. I just don't buy it.
[Nexus 9 General] USBhost:
I happen to disagree with you
[Nexus 9 General] Chyeo1979:
Yours is not on stock? I guess they are referring to the stock software right of the box.

I dun believe 10 hrs is possible too. If 90% is internet browsing, i dun even believe can get >6hrs
[Nexus 9 General] singmokjai:
Nexus 9

It actually took me about 4 hours and 15 minutes for a full charge from 5% battery life to 100%. I used the charger out of the box. Do you have other recommendations you can link me through Amazon? Also do you charge with the tablet idle with display off or do you charge it while its off?
[Nexus 9 General] Semantics:
You can disagree. I see you aren't using stock, and I see you got a bit more than 7 hours SoT with pretty good usage. 7 hours =/= 10 hours. Not remotely close.
[Nexus 9 General] USBhost:
True im so not stock

I basically got 8

Thats only 2 away from 10h

When i have no school which will be soon

I will use Chrome for 10h straight to see how that goes lol

side note

the nexus 9 uses less power on idle than my nexus 7
[Nexus 9 General] Hiro Nakamura:
How do you know it uses less power on idle?
[Nexus 9 General] USBhost:
Using Elixir
[Nexus 9 General] .vermilion:
I'm pretty satisfied with battery life. My Nexus is currently recharging. I got just a bit over 30 hours with ~ 8 hours SOT.

What I was doing:

- Set up the tablet (you know, download all apps I needed, screens, testing, ...)

- Facebook, Messenger

- Chrome (not that much)

- little bit of YouTube

- reading a book (~ 4 hrs)

When it's fully charged and I'm on my second cycle I'm going to post screenshots.

My boyfriend owned the Lenovo Yoga Tablet 2 (10") - Battery is slightly better (though Lenovo said it'll last for 16 hrs... ha ha...)
[Nexus 9 General] avilancaster:
That's not bad- I had about 7 hours, setting up, chroming, and I did a whole bunch of netflix on it. I suppose that is acceptable.
[Nexus 9 General] jd1639:
10+ sot today. I'll upload pic from my pc. Can't do it from my mobile
[Nexus 9 General] .vermilion:
Okay, I completed my second cycle.

Here are my stats.

I was doing:

- 5 hours Chrome

- 1 hour XDA

- 1,5 hours Facebook and Messenger

- Set up my Bluetooth keyboard and typing shortly to test it.

- Brightness at minimum

- no battery saver modus

Sent from my HTC One (M7)
[Nexus 9 General] hirndurst:
5 hours Chrome ... Nice! Are you on stock kernel/ROM?
[Nexus 9 General] .vermilion:
Yes, I'm completely stock.

But I have to admit (I added it a few seconds ago): The Nexus was on minimum brightness the whole cycle.

Sent from my HTC One (M7)
[Nexus 9 General] JXulo:
So far not impressed. 40% remmaning battery with 3:25 screen time. All i do is playing rise of berk for less than 5 minutes and browsing. I will try it a few more days because it is the fisrt day with full charge. For comparison my girlfriend with a samsung galaxy tab pro 8.4 has 23% battery remmaning with 5:15h of screentime. Brightness always on 20% +/-(on my nexus 9).
[Nexus 9 General] singmokjai:
What you guys think? Still on first cycle , received my tablet 12/12/14.
[Nexus 9 General] sale 83:
I think it was turned off completely for like seven days, and turned on seven times, just to be used a little.
[Nexus 9 General] singmokjai:
lol I turn it off when I head out to work so I mainly only use it a little at night time. I turn it off when I sleep as well so I'm just only using it as needed. I guess this way battery life will be fine but should I start doing some gaming or heavier use I should see battery life decrease faster.
[Nexus 9 General] JXulo:
Brightness between 20-30%.

.
[Nexus 9 General] Semantics:
This is about what I get. Tablet seems to sleep like a champ, but with 30% brightness, doing anything with the screen on drains it fast.
[Nexus 9 General] blakeslee14:
4.5 hours of screen on time. Brightness was at 35% to 40%. Seems alright. Mostly chrome and a little candy crush (yup I'm addicted).
[Nexus 9 General] JXulo:
Yes, during the night(wi-fi off, battery save mode) it seems to lose only 1% battery. Even during the day without battery save mode and wi-fi on when in idle it loses very little but when i'm browsing it looks like my galaxy s4 lolol.

But to be fair today i'm a little bit impressed. I think that maybe i will reach 5 hours for the first time. Not outstanding but much better than before. I need more days to test it.
[Nexus 9 General] R3Lax1:
Not sure if this is the right thread, but is it something to be concerned of that battery health is shown as dead when the tab has about 15% of charge left? Pic related.
[Nexus 9 General] blakeslee14:
Curious, I wonder what mine says when it has low charge... I'll keep a look out
[Nexus 9 General] di11igaf:
Seems alright? That's horrendous. That's decent nexus 5 time, for a 9" tablet that's bad, it should be double that. I literally have to keep mine plugged in for the most part, which doesn't bother me too much, but battery life on this thing is a joke.
[Nexus 9 General] JXulo:
Agree, my personal best was 5 hours and all i did was play a little "facebook game" (rise of berk) and browsing. But my average is 4/4:30 and to reach this values i need to discharge it almost completly (which is bad to battery if we do it every single time).

And i need to charge it every single day, at this rate (and with the help of the heat because the device is always warm) this battery will not last long. In one year i suspect that i can't even reach 3 hours of use due to battery degradation.

I wait two years for a tablet like this, it's almost perfect and i really love it but i need a device that at least reach the end of the day. I can't even use it for a full afternoon in work...maybe ipad air2 (or even air 1) will be my first idevice.

Sorry for my lamentations, maybe my expectations for a tablet battery was to high...i don't know but i need to try something different at least to see if the problem is my expectations or the tablet itself.
[Nexus 9 General] Neomastermind:
I actually returned my tablet nearly one or two weeks after I bought it. The combination of bad battery life and the heat generated when using chrome was unacceptable.

I so wanted to get away from my iPad 3 which lags doing a lot of things, bit here I am still using it. Its battery life is insane. Once I had it on standby for 30 days with 14-15 hours of actual use which was mainly book-reading and internet browsing.

That's what I want Google. I want out of apple for my tablet needs. Give me a tablet with iPad battery life.
[Nexus 9 General] ram130:
I returned my N9 after 3 exchanges. I finally learned to stop making EXCUSES for Google. The facts were there. I just needed to stop ignoring them. I'm much happier now.

I got the iPad mini a month ago. Battery life use to be 2days with 13-14hrs of usage. Now it's got even better. Getting 15-16hrs of usage and 3 days. That's near 10-11hrs of screen on. I'm impressed. As much as I hate iOS awkwardness and annoyances. I've grown to love it's battery life. Consuming media on it is awesome. Then I got my N7 to hold me over.

As for your performance issues. I think the iPad 3 is the issue. The newer ones are freaking fast. You'd probably love the Air 2. I'd get it and try it. If you don't like it any better return it in the period. That's what I did for the Mini 2. I didn't EXPECT to appreciate the thing. Such a good feeling not worrying about going to work with 40% battery life and coming back with 15%. Lol. Any way I'm done. Sad about the N9. The hardest part for me was letting go.

Sent from my Nexus 7