Develop Bugs

Holy bad battery life Batman!

I'm on Stock 2.2 US and Battery Life is HORRENDOUS. I have the Moto Charge app that displays actual battery in the status bar. I charged to 100%, wiped battery stats, turned it on and after 6 minutes of no use, I'm at 97%. What am I missing here?

Are there any apps constantly running in the background?
Do you have bluetooth/wi-fi/gps switched on all the time?
Are you using your phone somewhere that's unusually hot, cold or humid?

Step666 said:
Are there any apps constantly running in the background?
Do you have bluetooth/wi-fi/gps switched on all the time?
Are you using your phone somewhere that's unusually hot, cold or humid?
Click to expand...
Click to collapse
No, no, no, no, no

How long have you had it?
Has the battery always been this bad?
Has it only started recently? Is there some sort of cause, something that happened that has brought about this poor performance?

I just got the phone from a friend but I do not believe it to be an issue directly related to this specific handset.

Having GPS "on" all the time will not drain your battery as it is only being made "available" when an app needs it (mine is always checked and has zero effect on the battery until actually used). Did you do a factory reset after installing 2.2? On the Moto forum many issues are resolved with a reset.

hah2110 said:
I'm on Stock 2.2 US and Battery Life is HORRENDOUS. I have the Moto Charge app that displays actual battery in the status bar. I charged to 100%, wiped battery stats, turned it on and after 6 minutes of no use, I'm at 97%. What am I missing here?
Click to expand...
Click to collapse
Lithium-ion batteries have a big drop off at the start of the discharge profile.
They will then maintain a fairly steady state between about 80% - 40%.
A 3% change, therefore, from 100 to 97 is not equivalent to a 3% change from 80% to 77%.

I'm pretty certain it is specific to your handset - most Defys have very good battery life.
Here's my handset:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
At that rate, it should last ~5 days.

There are always something running in the background. Install a cpu monitoring application and see if the cpu is running wild.
In my case, 1% power lasts for 3~5 minutes usage (game, movie, surfing etc), or 2 hours standby (wifi off), or 1 hour standby (wifi on).

I checked Battery Use, there is nothing crazy. I've also checked Battery History and nothing is using the CPU or keeping it awake. I actually wiped the phone last night, didn't have a sim card in it and left it on over night and it lost 14% in 7 hours. It shouldn't have even lost 2% given that it wasn't connected to a cell tower. I have wiped it twice.

hah2110 said:
I checked Battery Use, there is nothing crazy. I've also checked Battery History and nothing is using the CPU or keeping it awake. I actually wiped the phone last night, didn't have a sim card in it and left it on over night and it lost 14% in 7 hours. It shouldn't have even lost 2% given that it wasn't connected to a cell tower. I have wiped it twice.
Click to expand...
Click to collapse
I am of a differing opinion.. I think these android devices have terrible battery life.
That being said, invest in a few of the cheap Hong Kong 1800mAH batteries on ebay.
I had a good experience ordering from "farmerseller". Curiously, I ordered 1500mAH batteries but received 1800 mAH batteries..... it took a while to arrive, but they work great and the charger is nicely designed.

luxdesigns said:
I am of a differing opinion.. I think these android devices have terrible battery life.
Click to expand...
Click to collapse
Compared to what?
What's your frame of reference?
I'm not aware of any other smartphone with specs similar-to or better-than the Defy's that gets anywhere near the battery performance my phone does.
Everyone I know with Galaxy Ss or Desires charges basically every day, one friend with an iPhone4 can get a couple of days out of it but most are only a day, friends with Blackberrys get a couple of days or so.
I regularly surpass 3 days of what I would call normal usage - web browsing, texting, a bit of gaming and the odd call here and there.

Are there any ROMs known to get better battery life? On both my N1 and NS, certain ROMs performed LIGHTYEARS better than other ROMs in the battery department. This is a well known fact that Android is inconsistent on battery life.

So I wiped, re-wiped, flash the beach update.zip, wiped, re-wiped and I'm not confident the wipe is working. http://forum.xda-developers.com/showthread.php?t=988036
Regardless, I also find it odd that my battery was at 85% and, after the flash/wipe, it charged to full in <10 minutes.

Give it a few days of usage and see the results afterward. Basically it needs some cycles to re-create the battery stats after wiping.
You can also install Powertutor to check what apps are "consuming" the battery.
From my experience: with light usage I made once 3 days but normally 1-2 days is all I get (3g, some talks, 30 min browsing, some ebook reading). It was the same with my past 2 Android phones and some 4 Win Mobile phones...
When you are in a really tight spot do the usual tricks: 2g only, disable APN, don't play too much with the phone. You will probably get 3-4 days in one charge

I updated to 2.2.1 also, and battery life went right down the tubes. I lived with it for two days, and then did a factory reset, and now I have better battery life than with 2.1. I really didn't want to factory reset because of all the fine tuning I did, and not to mention re-downloading all the apps and setting them back up, but I must say it was worth it. After 13 hours I'm at 30%, and that is with heavy use. I started at 100% and in 10 hours without using it much at all, it only dropped 10%, so 1% an hour I can live with. Once I started playing game it went fast, but that is to be expected.

Ahhh!!!!! You guys are killing me from laughter. Don't take this the wrong way....but read more items on these forums...they are a welath of information. First off.... battery stats are wiped. It will take a few days of charging/discharging for the phone to get an accurate idea of actual use. It needs a baseline created. Don't worry yet. It can take up to a week to get really good stats. As for the horrible life on 2.2....did you wipe battery stats before flashing? If not thats your problem. You have to wipe the stats when you go to 2.2. Different profiles and usage. It's mentioned in a number of the roms. With steady hard usage I'm averaging about 2 days between charging. On standby with no use the best I have gotten so far is 6 days. RTFM.... Hope this helps out.

My battery stats after 1st full day of normal use.

Switched on 8am, more than average use.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Sent from my Galaxy Nexus using Tapatalk

links are just blocked at work, nvm.

Links working fine here...
That's probably what I'd get out of my NS if I used it fairly heavily... the display is a battery killer on that too. So about average, then.

Don't know what happened to the quality though,looked OK when I took them!
Hoping when this mobile data problem gets sorted battery life may increase as my phone was all over the place today!
Sent from my Galaxy Nexus using Tapatalk

Ouch, thats some serious drain. I was hoping for at least 18hrs. Still not a deal breaker for me.

Gosh, why is yours so much better than mine. Feeling like I have a dud here :/

3 hours damnm

Thats right around what I get on my charge on 3g only.
Sent from my SCH-I510 using Tapatalk

2H 55 of screen time looks to be pretty lacking if I'm not mistaken?
The Galaxy S II video run downs get like 8H or 4H on web browsing.
But yea, diff situations

Your pictures are broken can't see any of them.
Edit: 3h screen on sounds pretty normal to me. Depends though on the brightness of the screen.

pewpewbangbang said:
2H 55 of screen time looks to be pretty lacking if I'm not mistaken?
The Galaxy S II video run downs get like 8H or 4H on web browsing.
But yea, diff situations
Click to expand...
Click to collapse
Those are completely different. They start with a full battery and just play videos or browse the web for that amount of time. With this he was using for the phone for random things and still had the screen on for 3 hours.
On that note, how is it possible to have the screen on for 3 hours of a 12-hour day? You literally spent 1/4 of your day looking at the screen? Do you not have a job? My phone sits in a dock on my desk, but I probably use it around 15 minutes per day while at work, and then another 45 min or so after work (so total screen time, if it wasn't sitting in the dock, would be around 1 hour for an 18 hour day).

pewpewbangbang said:
2H 55 of screen time looks to be pretty lacking if I'm not mistaken?
The Galaxy S II video run downs get like 8H or 4H on web browsing.
But yea, diff situations
Click to expand...
Click to collapse
Those run down tests are from 100 to 0 doing 1 thing. This is throughout the day. The phone is still draining when the screen is off.

yea i understand.....but basically the screen time is how long the screen has been on throughout the day correct?
I had a galaxy S and it used to get like 4-5 hrs of screen time throughout a 12hr day. With the extended battery i could get about 6-7hrs of screen time.
Now on the iPhone 4, i get 2hrs of screen time with 80% battery left and had a standby of 6hrs. But yea....its iOS
Idk, 3hrs of screen time seems ehh to me. Im still probably gonna get the phone though, tired of iOS once again. Went from 3GS to Galaxy S to iPhone 4 and now possibly Galaxy Nexus....or wait for GS III

Wifi radio power on all day?

Several people who've had the phone for a few days have said the battery life gets better after a few charging cycles.

Calibrate the device, leave it off then charge it till it's full. Then use it till it is dead, then charge it again while switched off and keep doing that for the first week when you buy a device any device that uses a battery. I've always done this to my phone and my wife's sometimes friends too. After that the battery is calibrated, then if something goes wrong with the drain you would know, or if the battery life actually sucked Case 'n point EVO 4G.

yea, 3 hours used 56% of the 85% of the battery that was used. so really should be able to get 5 to 6 hours of just screen on time.

I uninstalled my virus protection yesterday and turned off sync and wifi whilst at work today about 11am and battery stats better today. Haven't been in a low signal area today so no problems or slowdowns caused by 2g/3g.
Taken off charge about 9.30am
Wondering if its the virus protection taken off or disabling sync and Wi-Fi or the fact I was in 3g area all day that's improved it.
Sent from my Galaxy Nexus using Tapatalk

Signal strength is usually the main problem I have...
Is there a native ability in ICS to disable WiFi scanning? ie - Leave WiFi on, but disable scanning for networks...

OP, I'll bet your batt life would be 3x better with something like Tasker managing your Wi-Fi connection.
IMO, BEST.ANDROID. APP. EVER.

Have you managed to get over a day of battery life?

The phone is great but the battery really bothers me.
If I use my phone a bit it doesn't get me through the day. Sometimes i get as low as 8 hours of use with tops of 20 or so hours.
How do you manage it?

Fking1 said:
The phone is great but the battery really bothers me.
If I use my phone a bit it doesn't get me through the day. Sometimes i get as low as 8 hours of use with tops of 20 or so hours.
How do you manage it?
Click to expand...
Click to collapse
I use an Apex kernel and a 2000mah extended battery

Mines been great. Yesterday I was at 17+hrs which included over 3hrs of screen time and 1 hr of voice calls. I've only had my phone for less than a week, and have twice gotten over 4hrs of onscreen time (all with stock battery).
Running AOKP Milestone2 ROM with stock kernel.

I about a day and a half nearly 2 with stock and moderate use.
Batteries pretty damn good, you must have something installed that's eating it up. There's a good battery guide somewhere on these forums, usually helps track down the cause.

I usually get about 3 hours of screen time before I need to recharge. That should be normal.
Sent from my Galaxy Nexus

AOKP + Franco kernel + 2000 mAh

Got two days of battery life just now (1 day 20 hours, to be exact). That's with 2h18m of screen time and 4h2m of voice calls. Screen time is mostly due to text messaging, Facebook, Foursquare, Twitter and Google Currents, so I guess... light to moderate usage?
WiFi is always on, Data is off, Sync is on (except for FB sync), location services off. Didn't sign out of Talk, but did sign out of Latitude.
Also, since I installed Facebook, when you run it for the first time, it downloads a lot of background data, regardless of sync settings. I let it do its thing while it's still charging, and it was all good after that.
Using AOKP b20, Franco 13.1, and stock battery.

36 hours is the most I've gotten out of the phone, but I did screenshot this not too long ago.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}

I never get more than a day, but i use my phone very much because studying without my gnex is boring. I have the original gsm battery.

Fking1 said:
The phone is great but the battery really bothers me.
If I use my phone a bit it doesn't get me through the day. Sometimes i get as low as 8 hours of use with tops of 20 or so hours.
How do you manage it?
Click to expand...
Click to collapse
I would say the stock battery is borderline adequate. I find that on the stock system, if I use the screen for more than 3hrs, and have all my services sync'd, bluetooth, a few calls once in a while... I would have a hard time struggling to get to the end of the day without the phone giving me a battery warning.
How I've managed it is to get the samsung 2000mah extended battery. It's not a dramatic difference, but enough to make it noticable.
As well, I've kept the screen to about 40%, used a dark wall paper, loaded franco kernal and tweaked some of the settings to be more battery efficient.
Overall, I think it's acceptable right now. At least for how I use it.
I also find that my battery drains quite a bit where I work as the cell signal is on the borderline between no signal and 1-2 bars. That's why I keep a charger at work as well as in my car to give it some extra juice.

I find the battery is actually quite good.
I upgraded from a blackberry tour, and with similar moderate use the nexus actually gets me more battery use. However both phones being idle the blackberry lasted for days.
Overall i'm never away from a power source i can charge my phone, so as long as it lasts me roughly 1 day i'm good

Stock battery
Rom: aosp self-built from aosp master branch
Kernel: at the time, franco's nightly #8 or #11, can't remember exactly
Usage: light (3h screen on)
Went almost 3 days on one charge.

Nerfsuperball said:
I find the battery is actually quite good.
I upgraded from a blackberry tour, and with similar moderate use the nexus actually gets me more battery use. However both phones being idle the blackberry lasted for days.
Click to expand...
Click to collapse
If you can't get days while idle with your GN, then something is definitely wrong.

vapotrini said:
If you can't get days while idle with your GN, then something is definitely wrong.
Click to expand...
Click to collapse
Honestly I can't say I've let my gn be idle for days. Its far more useful then my bb was.
Sent from my Galaxy Nexus using XDA App

I don't have a nexus yet but would like to know if switching to 3g only improves the battery length significantly?
Sent from my R800x using Tapatalk

two days. Medium use.
Sent from my Galaxy Nexus using xda premium

I got my nexus 4 days ago.. Since then im harassing my phone.. Literally.. Im constantly installing application, customizing the homepages, making icons, widgets etc, surfing on web, exploring the market. 100% of time, Wifi or mobile data is in use (although i got unlimited data plan here (with speed of 4 mbits and 1 mbit upload), my wifi is more faster than mobile data.).
So i havent had a day with "normal" or "moderate" use on my GN.. And, battery lasts for over 24 hours.. And, autosync is always on, brightness is on 40% aprox, screen sleep 45 seconds (basicly its not sleeping cause im harassing it all the time )
Im all stock to the bone, just unlocked bootloader and rooted..
Im wondering what will happend when i start using my phone with moderate usage ..

Hmmm there are some interesting answers on this thread. The battery and the low sound have been the sole disappointments for me on the GN.
I get about 3.5 hours screen time before i have to recharge.
I guess if i turned everything off i could get better performance battery wise. But why would i spend almost $300 on a phone only to not use it? I am complete stock at the moment because i don't want to void the warranty but while i waiting for 4.0.3 i will be regularly using the hell out of my phone with a spare stock battery.

batteries have yet to perform at the level of the rest of the hardware, it's a fact. bear with it like the rest of us. of course we bought the phone to use it.
if you need battery life above all, turn off sync, it will do wonders.
personal pref: for more available resources, uninstall that widget crap, homescreens full of that i dont know whats the point of using them, even multiple homescreens, i rather have really important stuff on the launcher and just one homescren, black bg, no widgets. these are cpu and memory hogs, as well as 3rd party task killers, system monitors... keep it simple. less is more.

I assume no more than a day on my gn, but, as stupid as it sounds if you turn off the 3g and only enable 2g you improve your juice a lot. Most of the time we only need 2g.

[Q] Pathetic Battery Life, even with 3800mah extended battery. WTF?!?

This is irritating me immensely...my Galaxy Nexus has yet to last me a full day on a charge. I bought a Hyperion 3800mah battery and I believe it really did extend my battery life. On Sunday, I was home all day and my phone was connected to wifi. I used it quite a bit and the thing had 80% when I went to bed.
Today and yesterday, going to school, my phone is just about dead when I get home, at 2:30. I did use my phone, but not heavy at all. Spent the most of the day in my pocket. I had nothing on both days. No bluetooth, GPS, I had sync off when I went to school today, then I turned it on around 1 o clock or so. I used full screen brightness when I was outside for a few minutes, otherwise it was on low. The thing is warm to the touch like its been running frantically. I'm lead to believe that its something to do with the LTE radio. But what??
Took some screen shots of my battery page, had 4% left.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Please please please help me. I've read people getting 2 days on a charge with a 3800mah battery...I'm drooling for that ability.
Thanks!

It looks like your spending lots of time in area's with bad reception. I'm using the sedio 3800mah and I have no problem going several days on one charge. Only time it drops faster is when I have crappy reception and the radio's are pulling more juice. On heavy days I have wireless tether running all day, and a couple hours of games and still have 40+ percent at the end of the day.

there is also some crap app installed that keep ur phone awake..
ur phone should be awake only when the screen is on (or so)..

your high % of cell standby should give it away.

look at your signal the red is all the times with no signal meaning that whole time the phone is searching for signal. plus 49 %of screen on time that looks to be half of 7:49 so almost 4 hours of scren time is good just need to fix your signal problem plus draw something kills your battery as well

lordgodgeneral said:
It looks like your spending lots of time in area's with bad reception. I'm using the sedio 3800mah and I have no problem going several days on one charge. Only time it drops faster is when I have crappy reception and the radio's are pulling more juice. On heavy days I have wireless tether running all day, and a couple hours of games and still have 40+ percent at the end of the day.
Click to expand...
Click to collapse
+1 to signal causing drain
Sent from my ADR6425LVW using XDA

dco717 said:
plus 49 %of screen on time that looks to be half of 7:49 so almost 4 hours of scren time
Click to expand...
Click to collapse
is not like that..49 % is the power consumption of the screen in relation to the other things that drained the battery..with easy word, you cant know the screen on time if he doesn't say u

True...well he needs to do a factory reset and see if it helps
Sent from my Galaxy Nexus using XDA

Wow, poor to no reception, high awake times, high screen on times...it's a miracle your battery lasted as long as it did.

dco717 said:
True...well he needs to do a factory reset and see if it helps
Sent from my Galaxy Nexus using XDA
Click to expand...
Click to collapse
Factory reset doesn't help bad signal...lol.
Turn off LTE, bad signal will drain you fast but bad signal on LTE will drain you twice as fast.

Looks like you have a rogue app. See how much your phone is awake when the screen is off? That combined with bad signal=dead phone.

I see what you guys mean about awake mode. Yea my phone feels like a warm coal all day. I uninstalled "Words Free" because I've heard bad thing about battery, I stopped using the beautiful widgets weather app, stopped sync with soundcloud, and I got an airplane mode widget for the bad reception area. We'll see how long I can stretch my battery tomorrow.
I read up on how Light Flow light might drain the battery. The LED light has remained stuck on a lot, so I uninstalled it. I'll post a battery stat tomorrow night. Fingers crossed.

I can vouch for bad reception draining the battery.. that should clear up your problem.
Sent from my Galaxy Nexus using xda premium

I had the same problem but get this app called "2X Battery", my batter lasts the whole day now! Get the PRO version, its actually worth it and it works wonders!
I have the extended battery also

yep bad reception... once time i left my phone one in my bag while on an airplane... not in airplane mode or anything... battery went dead in about 2 hours due to no signal

Pretty sure the bigger problem is the phone waking up while the screen is off. You should run your phone for another day and look at the list of apps that are draining your battery.
A few good things to look for? Google + or other programs constantly checking for messages your location, or updates, e-mail being pushed to your phone automatically, Wifi on while in sleep, and widgets.

My battery is **** also on GSM version my galaxy s2 would have 2-3% drain per hour most time less Nexus seems to drain 2-3% in 15mins its terrible wish i never changed.

Just how TERRIBLE is the battery life ?

I wanted to get this phone as a replacement to my Nokia N8.
Having been loyal to Nokia over the years, I'm used to absolutely excellent battery life, where I get a good 2 days of normal use, or easily get through 1 day of heavy use.
Would the Galaxy Nexus be a really bad step down ?
Can anyone suggest their average battery life when having:
25% screen brightness,
GPS/BT/NFC/etc off until needed.
Sync only for WhatsApp
Messaging 1-2 hours a day
Music 2-3 hours a day
Browsing 1 hour a day

I get 8-9 hours standard usage
Sent from my Galaxy Nexus using xda app-developers app

stewie325 said:
I wanted to get this phone as a replacement to my Nokia N8.
Having been loyal to Nokia over the years, I'm used to absolutely excellent battery life, where I get a good 2 days of normal use, or easily get through 1 day of heavy use.
Would the Galaxy Nexus be a really bad step down ?
Can anyone suggest their average battery life when having:
25% screen brightness,
GPS/BT/NFC/etc off until needed.
Sync only for WhatsApp
Messaging 1-2 hours a day
Music 2-3 hours a day
Browsing 1 hour a day
Click to expand...
Click to collapse
If only 3G, you'll probably pull about 12 hours and a little under 3 hours screen on.
-Brought to you by Marino's Galaxy Nexus-

Mine's on WiFi all the time with all the syncs and stuff. A few calls and messages + mild browsing. Normally I get 14-16h. Maximum was 24h with the wifi turned off I guess. Not the best results, but bearable.

I get about 4 hours screen on time, and a full day no problem.
Just charge when you go to bed at night and youll be good to go

I usually get one and a half days of standby time (average 37 hours as reported by GSAM Battery Monitor). So I usually only charge every other day. However, my screen use (1-2 hours) is much less than most people on this forum. If I use my phone heavily with screen on >2 hours, then it lasts just one day.
1-2 hours screen on time.
Brightness: 11% indoors, auto outdoors
GPS/BT always on
40 mins/day streaming Pandora music over HSPA+ and BT with screen off
Wifi + Airplane mode always on at home, with Wifi High Performance Widget
VoIP (Sipdroid) connected whenever on wifi

It's comparable to the selection from any OEM, though 4G and Jelly Bean's Project Butter are the top offenders (alongside display, that's more a given, though.)
Sent from my ADR6400L using xda app-developers app

Install rasbean and franco/trinity. Your head will be blown with the awesome battery life. I wont say more, test it yourself.
Sent from my trasbeaned Galaxy Nexus.

thegtfusion said:
Install rasbean and franco/trinity. Your head will be blown with the awesome battery life. I wont say more, test it yourself.
Sent from my trasbeaned Galaxy Nexus.
Click to expand...
Click to collapse
These statements are invalid, people have reported great battery life with almost every combination out there. Secondly, OP you won't last more than.. Well could be 14 hours maybe 18, 14 especially assuming you use data to web browse. but it really depends on screen on time and, how spread out your usage is.
Sent from my Galaxy Nexus using xda premium

It will be a step down.
You will never get 2 days of battery life under any useful circumstances.
Unless you neuter your phone, as I've mentioned in another thread.

In all honesty, the gsm/cdma versions need to be compared totally different. I've had both and can say the gsm version can easily get 3 hrs of screen on time without even trying and the cdma version (toro) struggles to get 2hrs. So, when somebody replies about battery life, they really need to specify which version of the gnex they have or you could specifically ask for maguro/toro/toroplus users.
BTW, the screen on times I'm specifying are not on wifi and are using HSPA+ for the Maguro and LTE for the Toro.
On Maguro (GSM Version), I routinely get 2 days out of my gnex with light/normal use.

I have the GSM Galaxy Nexus and I keep my phone on Airplane Mode at home, work, & school (since all my calls & texts are made through google voice anyways) & data while I'm on the go. I mainly use Facebook, Google Voice, Groove IP, Instagram, Light Flow, Google Search (4.1), Google Maps, & music. Occasionally I game, watch movies, etc. Here's a typical day of use, 5 hours of screen time:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}

We don't have 3G where I live - but I have to charge my phone every night.
My usage is something like this: random surfing at work (read news and all), send quite a few texts (or Whatsapp messages), play music for almost 50 minutes straight... when I'm home, I'm left with 60 or 50%.
I do have a charger at the office though - but I don't always use it.
It depends on how strong your cell signal is; if you're in a spotty area, the battery drain will be higher. It also depends on the kernel you use (right now, I'm trying to find a decent kernel - not the stock one since I get random reboots on the stock kernel... my phone didn't have this problem before, oddly - even with Jelly bean on it... yeah, confusing... but I digress).
Anyway - it will last you a day easily. 3G? I think it'll last you a day there as well. It depends HOW you use your phone.

Thanks for all the replies. As a reply to one poster, yes I am getting the GSM version as there is no LTE really in the UK. But it seems my battery concerns are true looking at most of your answers. I'll have to be really really careful in order to get two days use out of it. Probably best to spend a bit more on another phone. Perhaps the GS2, but that doesn't seem to be much better..

If the battery lasts you one day, you shouldn't be so concerned about it. Not like you can't charge it during night... Also with a little optimization, it can easily last you a day. If you are still concerned about your battery, get an extra battery or an extended battery. Also I had SG2 before and the battery is better than Gnex, but not enough to get it over Gnex.