yashsingh1/xdaforums huggingface dataset:
[Nexus 9 General] Scotlac:
Yep, I've heard reports of 10 plus hours with video playback. The major battery drain seems to be associated with gaming (understandably) and browsing (not so understandably).
[Nexus 9 General] Diesel779:
I received my iPad today. Once I've fully charged it I'll posts stats as soon as the battery is close to zero. I love Android but this iPad air 2 is unbelievable. It's better built, more responsive I could go on. The Nexus 9 is no match for the iPad Air 2, as much as I'd love the Nexus 9 to be the better of the two, it simply isn't. Infact it's not even close to the Air 2. 6+ screen on time? lol Some OnePlus one owners are getting that. Give me how ever long it takes for the battery on my iPad Air 2 to go from 100% to zero whilst being used daily for all sorts of tasks and I'll post stats, here, in black and white and show you just how good the iPad battery is. I was happy to pay £320 for my Nexus, I thought it was a reasonable price. Then I took my Air 2 out of the box and realized what £80 extra gets you. I love Android L and I can't wait to get the update on my phone, but the Nexus 9 is a POS in build quality and battery life.

But, like I say - Don't take my word for it I'll post stats as soon as my battery hits near zero. 6 hours SOT is terrible for a tablet. And I don't buy that you could of got 8 hours if you had wanted to, if you could of got 8 you would have.
[Nexus 9 General] Lucke:
i've had it for a few weeks now and i'm pretty impressed with the battery life. about an hour of gaming and another hour or two of browsing and it's lasting almost 3 days on a charge (although going into a deep sleep for ~9 hours while i'm at work helps that).

that being said, i don't care about SOT as it's a worthless, arbitrary stat based on a specific, individual device, apps installed and what is getting synced, etc... and as long as you're happy with the battery, nobody else can tell you that it's either great or terrible.
[Nexus 9 General] brushrop03:
I charged it because I was going to bed and had a full day the next day. Why wouldn't I charge it? Could have streamed video for quite a while on 20%
[Nexus 9 General] Diesel779:
Streaming video doesn't use much battery. Try browsing on Chrome and get 8+ hours. The N9 has absolutely terrible battery life when being used to browse the web, use email, play games. But watching video isn't a problem for most tablets. Like I said - I'll post the iPad Air 2 stats as soon as my battery gets close to zero and you'll see for yourself how poor the N9 battery is in comparison.
[Nexus 9 General] USBhost:
Hmm lets see why

ipad air 2 has an 8600mAh battery

And the Nexus 9 has an 6700mAh battery

Thats an 1900mAh difference

---------- Post added at 12:46 PM ---------- Previous post was at 12:17 PM ----------

+1 Aye
[Nexus 9 General] chrisnewton:
I mainly use a tablet for Web browsing.. Really hope they can push a fix out to make it last longer as I really want to get this tablet.
[Nexus 9 General] TheDom82:
iPad Air 2 is actually 7340 mAh. So the diff is 640 mAh. which is still a significant size difference.
[Nexus 9 General] USBhost:
Oops

Then the ipad air 1 was 8k one lol

search engines

Ty for clearing that up
[Nexus 9 General] brushrop03:
They will...
[Nexus 9 General] volpo222:
Wow! Just found this thread.

I am glad to see I'm not the only one wondering about the battery. I was starting to think that I had a defective unit. Nope.

Stock N9, 40% brightness, 3.5 - 5 hours of average screen on time to ~30% capacity. The worst offender is Dolphin while browsing and or streaming video. The back gets quite warm, near the camera. I use facebook and twitter regularly, read a great deal using flipbook.

I like the hypothesis that the SOC doesn't scale back fast enough and that it is too quick to ramp up.

That being said I love the 'desktop like' performance that I'm seeing. Sometimes I'd say that it is even faster than my desktop. I've never had an android device render complex web pages faster. I'm hoping over time apps and OS will begin to work better.

Is it ok to use a 2 amp charger with this device? I'd love to reduce the re-charge time a little. The stock charger is only 1.5 amps and I'm not sure I get more than 1.3amps at best (I use a current monitoring app but am not sure if the result is correct - anyone know of a current monitoring app that correctly reports the charging current?).

I'm not overjoyed with the battery life of the N9 but the performance is really great.

V
[Nexus 9 General] brushrop03:
You can use a 2amp, but I think the Nexus will only allow for 1.5. Not sure though...
[Nexus 9 General] USBhost:
Well i went and enabled 2A

Its working vary well
[Nexus 9 General] ram130:
I got my third Nexus 9 today. So far battery life seems a little better. Still testing.

Well I agree. I just got my iPad mini 2. Battery life is insane. Let's recap:

I got the thing yesterday. First thing I noticed is the premium hardware. Buttons really stick out and proud. Harder to press. Huge fingerprint magnet. The Back always felt cold. Lol. More prone to slip in my hands than the N9. But not bad. It had most of my iPhone data so that made it easier get most of my apps downloaded. Long setup process compared to Android. Scrolling method is freaking annoying. Battery life makes my N9 looks like sh*t. No. Really.

I was downloading my apps all day since I got it at 3.30pm yesterday with 99%. Been on and off, browsing and stuff. Hit 74% around 9pm. Played GTA vice city for 10mins. Listened streaming music for around 45mins on the speaker at a good volume. Lots of messages, g+, hangouts stuff. Even reading for a few minutes. Battery was at 46% by the time I got home. Did some other stuff before bed. Went to bed with 28%. Woke up with 26% at 1pm. Notifications going off all night. It is now near 3pm on day 2 and I'm at 20% as seen in the pic below. My N9 been off since I got this iPad mini 2. In 23hrs I lost 7% with WiFi off and no notifications coming in. Turned it on. And everything came in. You can see the dip below in the graph. So I started at 73%. Watched a movie trailer at 70%, went down to 69%. OK. Not bad. Started typing this post around 64%. Now I'm at 59%.

Overall. iOS is a different beast. Nice to see how much attention Google gave it's apps on it. Stuff reloads on iOS too. But for good reason. Tabs and homescreen, not yet. It does it less than my N9 and that has 2GB of ram vs 1GB on iOS. I miss double tap to wake. As for the heat issues? None. Only when downloading my games did I see it get warm but no where near 93F unless charging.

Still prefer Android. It really has grown up for tablets. It just needs devs to stop being lazy and a more efficient OS with better memory handling. But with iOS 8. It's workable now on tablets but still feels backwards when doing certain things. But that Apps catalog though. What will I do? See how my N9 replacement works out.. I got 14 days, and if I want I can trade up to the Air 2. ﻿

They are working on GPU use for Chrome. Which will make it faster and more battery friendly. Fingers crossed.

Update:

Heat issue is here and proud on my third replacement. After 5mins of browsing in Chrome:
[Nexus 9 General] Diesel779:
Thanks for sharing the info. I'm nowhere near ready to post any real stats on my iPad Air 2 yet, but I will say that the battery life on this thing and the N9 are leagues apart. I unplugged my iPad Air from the charger yesterday at 3 pm, obviously it was at 100%. I did a little bit of Gmail and facebook around 4 pm. Then a bit of light browsing at around 7 pm (light as in 10 minutes, 1 tab) Then I used the Air 2 for an hour in bed, I used it for Gmail, Facebook, Facebook messenger and web browsing. I've just checked my Air 2 and it's on 94%. So that's 6& battery wit the usage I've stated and it's been off charger for almost 21 hours. No one has to believe me but I will, as promised post full stats once my Air 2 gets close to zero. A word of warning though: You may be in for a bit of a wait until this thing hits zero. I'll be doing a bit of gaming later (Asphalt 8) and streaming music, and maybe a bit of youtube. I'll keep you all posted.

I'll keep following this thread to watch for improvements on the Nexus 9. Whilst there's absolutely no chance I'll be getting rid of the Air 2, if the N9 shows drastic improvements I will purchase another one as I do really like that too.
[Nexus 9 General] Chyeo1979:
I was surfing on my N9 with the power cable plugged in. The battery level did not even maintain and continue to drop instead. That's really bad :(
[Nexus 9 General] Lucke:
i've seen none of these issues with chrome beta except for the heat issue (screen being on is the most likely reason for the heat i think).
[Nexus 9 General] ram130:
Sure thing but if they don't believe you. It's more the fact they don't want to admit how bad the N9 battery is for a tablet. Saying oh it gets this on video and that review says that. Especially when your stuck with it. You just keep hoping an update will improve things. Time goes by. Update after update. Same thing happened with the N7 and it's screen issues which turned out to be mostly hardware.

I'd be willing to work with the heat issue. Especially now that I got one with minimal light bleed. 3rd replacement. If only battery life was near this iPad mini. I was expecting at least 7-9hr screen on with 2days stand by. Not 5-6hr screen with 1 day stand by. Especially with L so called improvements and the big battery in this which mind you, takes forever to charge.

It's not the screen. Rather the inefficient CPU.
[Nexus 9 General] BennyJr:
To say inefficient cpu is rather bold, as it could be a number of factors
[Nexus 9 General] chrisnewton:
Gutted, really want this tablet but can't live with 5 to 6 hours ost, guess I'll have to keep my trusty nexus 7 and hope Google fetch out something better next year!
[Nexus 9 General] Badouken:
I got 6 and a half hours of SoT yesterday before my nexus 9 died on me , with heavy usage of games , video and browsing. I usually average on 5 hours of SoT. Today im already at 60% battery with 1 and a half hours of SoT and ive only been using chrome (also way hotter than normal today). I swear google just needs to fix google chrome, its obviously not optimized for the nexus 9 at all which is embarassing because they have updated it a couple times since its release. I have been happy with the nexus 9 though, im just a lil disappointed with the false promise of 9 hours of web browsing google promised. Maybe its possible with 0 brightness and everything off.
[Nexus 9 General] ram130:
Ok they made up the number and didn't test anything. Lol. I'm on about 10hr screen with the iPad mini 2 I got with 2 days off charger. Like. I'm shocked I still got 20% left. I was mainly playing around, browsing, showing the differences between it and my N9 today. Along with music playing. So far my two N9 are around this:

And the iPad is at 20% now. Like. Wow.
[Nexus 9 General] richii0207:
Smaller screen and slower processors = better battery life. Common sense there.
[Nexus 9 General] ram130:
Yes. But even my N7 was never this good. Lol. The max I got was 9hr screen only two times. I normally avg 6-8hrs with a day of stand by.
[Nexus 9 General] mk92595:
5hrs ost today. Currently at 15%.

GTA SA for 15 min, Streamed HD TV shows for 1hr, 11hrs standby.
[Nexus 9 General] machoua:
I also get this with my iPad air 2. And my father's iPad air. Sometimes even with 4 days stand by time with 10 hours of use. If I straight up use it for only emails and pdf reading/editing I get 14 hours and crazy stand by time.
[Nexus 9 General] ram130:
Yep. Still going too. At 16% now. Had a lot of notifications coming in too.
[Nexus 9 General] thoraz:
Looks like i'm having the exact same problem. While plugged in and under load, it seems to stop delivering the required amperage to maintain a "100%" charge. I've noticed this tends to happen a good hour or two into start of heavy usage.

dmesg example:

[136029.170234] healthd: battery l=100 v=4138 t=37.8 h=2 st=5 c=-1017 chg=a

[136089.170641] healthd: battery l=100 v=4210 t=37.8 h=2 st=5 c=-146 chg=a

[136139.977474] dhd_set_suspend: Remove extra suspend setting

[136139.982004] dhd_pno_get_for_batch: Batching SCAN mode is not enabled

[136139.982232] dhd_pno_stop_for_batch : PNO BATCH MODE is not enabled

[136149.170090] healthd: battery l=100 v=4205 t=37.8 h=2 st=5 c=-197 chg=a

[136158.923122] healthd: battery l=95 v=4186 t=37.6 h=2 st=2 c=-340 chg=a

[136209.170534] healthd: battery l=95 v=4223 t=38.0 h=2 st=2 c=190 chg=a
[Nexus 9 General] BennyJr:
So its weird, browsing chrome creates a lot of heat, but watching Twitch doesn't...hmm
[Nexus 9 General] rolrctermaniac:
I noticed the same thing
[Nexus 9 General] mk92595:
Chrome beta is your friend
[Nexus 9 General] ez4nick:
My nexus 9 is 2 days old and I've only gotten about 3 and a half hours screen on time on my first 2 charges. I definitely noticed the heating when using Chrome, it was consistently around 100 F when using Chrome. Hoping the battery life will improve with time. I have adaptive brightness on and the level set around 30%
[Nexus 9 General] ram130:
And like that. My battery is now at 5% with possibly 9-11hrs of screen if I can calculate it correctly. Honestly I'm shocked. Same usage I'd be charging by the end of day 1 on the N9.

My Nexus 9 is charging now with over 1day of stand by and 4hr screen. Looks like I'll keep the iPad since it more than exceeds it's promised battery life. As for the N9, updates could help. But if pass experiences are anything to go by. The difference won't be complete 360. Nvidia and battery life is just not there. Like many others I'll be on stand by.

The good. HTC finally improved the QA on hardware. My third replacement has considerable improvement in build. Buttons not flushed, less screen bleed and back cover doesn't push in as much anymore. Speakers still sound muffled. Otherwise heat and battery life are the two biggest concerns for me. Sure battery life with video is amazing. But mix usage pales. That iPad screenshot is with a ton of mix usage. Anyway. The N9 is close. Just not there yet for tablets.
[Nexus 9 General] googlephone:
You guys need to stop bring the stupid ipad battery time here.

You have no idea what usage time is on the ipad!

Usage time != screen time and there is no way to know the screen time on the ipad. Apple does it on purpose to fool the guys like you to give you the impression of much longer battery.

You need to subtract several hours from the usage time to get the screen on time and there is no definite foemula to do it.

So stop being fooled by apple!
[Nexus 9 General] ~ Myzrael ~:
The difference in battery life is consistent. I have had nexus 9 for 10 days before returning it and i have an ipad air at work for developing, the difference in battery life is huge, the ipad with same usage lasts 2 days or more, nexus 9 needs a daily charge. Saying that apple fools us hiding screen time is ignoring the truth. For me nexus 9 subpar battery life isn't a great issue, but if you consider its price it's impossible to not blame google.

Sent from Galaxy S4
[Nexus 9 General] ElementalXY:
Honestly speaking but why in the world are you comparing 2 operating systems that are in completely different situations? Android L was just released and is being fixed with not even the latest iteration of 5.0.x out yet with a new runtime (that's a seriously HUGE change in itself and will take time until it's stable). While you're talking about iOS 8 that's just a development of iOS 7 with small additional features and with bugs fixed and enough time for development already passing through a year. Yes the iPad's idle time is much better at the moment but in no way can you argue that to a tablet that's still a work in progress. Every operating system was like that and it will take time.

PS: The Kernel developers are even in alpha/beta stages so no way can you make a judgment yet.
[Nexus 9 General] Chyeo1979:
I love my Nexus 9 but if you use an iPad before, you will feel the gigantic difference in battery life compared to Nexus 9 yourself, no need anyone to fool you. Nexus 9 is even poorer than my 1 yr old Note 3.
[Nexus 9 General] MRobbo80:
I get 8hrs plus screen on

Apple= no more ROMs or kernels from XDA ? so if I have to sacrifice a couple of hours then so be it!
[Nexus 9 General] eded333:
Just got 10 hours and 22 minutes of screen time, from 100% to 2% (the actual time the tablet was on was 3 days and 4 hours, the screen off hours wifi was always disabled). The usage was not intense but it included internet surfing, comic reading, youtube and video streaming and ocasional gaming.

Not sure what all the fuzz is about, for me, a tablet that gets me on the 10+ hour mark with occasional gaming has an awesome battery life, maybe the experience may differ, but I'm sure everyone should be getting 8+ easily without heavy gaming.

For the Ipad lovers, the Ipad mini I have dosn't get me near this mark, so yeah I'm happy :).

Haven't got a screenshot, next time I do a full recharge I'll get it.
[Nexus 9 General] aleandre1974:
Hi, this sounds indeed great ! Would you care sharing your config details, eg. Internet browser, what games and for how long, more or less, you used them in these 10 hours. I like the Nexus 9 but can't really get above 6h30 sot within 24 hours run time using Firefox with adblock and some 30 minutes of gaming with need for speed. I also read ebooks for say 1 hour. Same result with Chrome, more or less. During 8 hours at night, I loose only 3% at most, so wakelocks are not the issue. All stock, Wi-Fi off while not plugged in and not used.
[Nexus 9 General] richii0207:
Battery life has been phenomenal.

(Hopes to end drama and get back on topic)
[Nexus 9 General] Diesel779:
My Air 2 is still going, I'm at 60% with mixed usage. So are you keeping the N9 too or sending it back?
[Nexus 9 General] Diesel779:
" with a new runtime (that's a seriously HUGE change in itself and will take time until it's stable" "Yes the iPad's idle time is much better at the moment but in no way can you argue that to a tablet that's still a work in progress."

So, the new runtime isn't stable yet AND the N9 is a work in progress. Yet it's being sold to the general public as a finished product at a starting price of £319. So Google are basically using paying customers, who are paying over £300 as Beta testers? No one is asking for miracles, but if you're going to sell a product to the general public worldwide, said product should be finished and not still classed as "Still not stable" AND "A work in progress" And if software bugs are found after release they should be fixed fast! As for the hardware issues the N9 is suffering, personally I think with the amount of different hardware faults there should have been a product recall. The Nexus 9 could of done with 2 or 3 months more work and testing before being released to paying customers.

Edit to add: Also, like it or not the iPad and the N9 although running different operating systems will be seen as direct competition to each other by the general public and therefore compared as such.

---------- Post added at 11:18 PM ---------- Previous post was at 11:01 PM ----------

I have the iPad Air 2 with a larger screen than the N9 and a faster CPU, And the battery life is way ahead of the N9. So your logic doesn't really work does it?
[Nexus 9 General] Diesel779:
As much as I like my iPad Air 2 something hit me tonight. I wanted to transfer a video file to my iPad the only problem is I run Linux, I have a Mac but I run Linux on it full time no OS X. Anyway, whilst there's always a way to get around something, trying to get this video file from my Linux machine to my iPad made me realise why I left Apple in the first place last year. I paid £400 for my iPad Air 2, then I have to put up with Apple dictating how I can use it and how I can transfer files to and from the device, and what format said files have to be. And that REALLY pissed me off! They just want to pull you deeper and deeper into their ecosystem so you're constantly spending money with them.

As good as the battery life is and as well built as the Air 2 is, I'm seriously thinking about sending this back and giving the Nexus 9 another try. If I could be positive that Google would the bugs and other issues quickly then I wouldn't hesitate. I really do like the Nexus 9 and I'm sure there will be kernels to improve battery life soon. I'm going to sleep on it, but being reminded of how Apple like to dictate to customers such as myself who've already paid a premium has opened my eye's once again. I'd be really gutted though if I ordered a new N9 and got one riddled with issues again.
[Nexus 9 General] Chyeo1979:
The comparison is more of a tablet vs tablet, not exactly brand vs brand. It's just a bit disheartening to be using a tablet (which I love) that drops a battery % every three minutes while I'm surfing. That's handphone standard to me.
[Nexus 9 General] eded333:
I use chrome as browser, for gaming I'm playing Sword&Sworcery (great game), and some Dark Guardian. I've disabled location and nfc. For interior use I disable auto brightness and adjust accordingly (normally lowerish). For reading I'm using comicRack and MangaWatcher (not available on the playstore), streaming and playback bubble upnp and mxplayer. Not much else I can tell you, I'm all stock. I'll post a screenshot of the battery history on this run. I've had the tablet since it was available and the battery has improved with this couple of weeks.
[Nexus 9 General] ram130:
True that they are different. But the facts and basics still stand. For a tablet it's terrible and comparable to a phones battery life. I'm sure it will get better. But this is the same broken story I've heard going from Nexus to Nexus, Updates to Update. I'm sure it will get there. But from being burnt on previous devices. It's hard to trust they will get it right one day. Especially on a $500+ device. I wish they made an announcement or something to say they are working on it. But no go. Especially after some chrome updates. One day Google will care about the overall consumer experience and up there quality assurance.

Gonna send it back. Hate charging near daily and it takes 5hrs to charge. Love the thing! There is just not enough reason to believe they spent quality time developing this. Doesn't feel worth the price tag. Especially if I'm questioning it instead of enjoying the device. As limiting as iOS feels to me. I at least don't feel like I regret the purchase.

Only die heart Nexus guys will hate what I'm saying. Cool. I'm ok with that.