Database Users

Real world battery test - unbelievably good

Hi, I have been decorating my small bathroom today and I have had my N1 sat on a shelf busily streaming music from last.fm over a wifi connection.
I had the volume up full and was listening for a good 7 hours. The battery was at 95% when I started listening and I expected the phone to shut down by mid afternoon but it didn't.
At about 6.30pm I finished decorating (for the day!) and looked at the battery guage. It showed 64%. I couldn't believe it!
Battery use is shown as 26% cell standby (good 3G connection all day), phone idle 23%, mediaserver 2%, and wifi was just 10%.
I always thought wifi was a battery drainer but apparently not on the N1

i get steady drain when indoors @ the office where i only get Edge no 3G. Is the battery drain as bad when searching for 3G as it is searching for a signal in general?
aj

To my knowledge the screen uses the most battery (other than voice calling). So if you were not using either of them it should last you a long time.

andythefan said:
To my knowledge the screen uses the most battery (other than voice calling). So if you were not using either of them it should last you a long time.
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Yea the brightness of the screen is to blame for most rapid battery drains.

I've found that forcing 2G when indoors is the best way to go (unless you still generally have solid 3G).
If you are in a solid 3G area, then just force 3G...
This gives you a much more stable network connection and means the phone doesn't have to work as hard, switching between EDGE and HSDPA.

gsvnet said:
I've found that forcing 2G when indoors is the best way to go (unless you still generally have solid 3G).
If you are in a solid 3G area, then just force 3G...
This gives you a much more stable network connection and means the phone doesn't have two work as hard, switching between EDGE and HSDPA.
Click to expand...
Click to collapse
how do you force a 2G connection?
aj
edit: network settings. got it.

ghostrida said:
how do you force a 2G connection?
aj
edit: network settings. got it.
Click to expand...
Click to collapse
Go to settings > wireless & networks > mobile networks and select only use 2g networks.
Edit: Nvm you ninja edited on me lol

gadgetgaz said:
I always thought wifi was a battery drainer but apparently not on the N1
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FWIW, the specs on the Google page list 6.5 hours browsing the web on Wifi vs. 5 hours for 3G so it is at least better than 3G.
Also, streaming FM probably runs the Wifi in bursts with some buffering rather than continuously, wouldn't it?

Also, streaming FM probably runs the Wifi in bursts with some buffering rather than continuously, wouldn't it?
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I'm sure you're right but the wifi radio is switched on all the time even if it just accessed data in bursts.

gadgetgaz said:
I'm sure you're right but the wifi radio is switched on all the time even if it just accessed data in bursts.
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Click to collapse
If it supports the WMM extension along with the router then it can request some low power support for maintaining the signal which drastically reduces the power needed when not actually sending/receiving data. It was created for things like WMA (which this phone doesn't have), but can be used more generally.

Last time I checked the screen display only used 4% at about half brightness ( maybe I'm wrong but I checked with bettercut shortcut )

ghostrida said:
i get steady drain when indoors @ the office where i only get Edge no 3G. Is the battery drain as bad when searching for 3G as it is searching for a signal in general?
aj
Click to expand...
Click to collapse
Your phone uses a lot of battery when searching for signal. Enabling Edge only should make that stop. My phone fluctuates at work because I'm in a big building so I just connect to the wifi and leave it.

I too am extremely satisfied with the battery life, for as fast as the phone is I wouldn't expect so much. I'm amazed, seeing it with such a small battery, this phone sips power.

just as a note, have had the 2800mah battery now for the recommended 5 full charges...phone has been on for 3 days now and is at 40%...crazy

nmeofdst8 said:
just as a note, have had the 2800mah battery now for the recommended 5 full charges...phone has been on for 3 days now and is at 40%...crazy
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Nice! How does the extended back affect your use?

wow, just 31% after 7 hours!!
I lose 10% just getting to work (1 hour) with very limited usage and edge only.

britoso said:
wow, just 31% after 7 hours!!
I lose 10% just getting to work (1 hour) with very limited usage and edge only.
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bouncing between edge and 3g drains the battery also.

Battery Life on Wifi - Outstanding!!

Basically, when I leave wi-fi on my phone has incredible battery life. If someone has already mentioned this feel free to bury this post, but to my knowledge it doesn't seem this has been posted yet.
With wi-fi off and 3g on
- Battery lost 5-6 percent per hour
Wi-fi on
- Battery lost 1-2 percent per hour (sometimes less than 1 percent depending on what your doing)
Right now after having my phone on for 34 hours my battery is still at 70 percent! I'm fairly certain this is because it disables the 3g radio altogether which apparently is a real battery hog. That or maybe my phone is just a fluke. I really don't know.
This also seems to be tied to the htc sense rom (correct me if im wrong) but if i remember correctly battery drainage increased when wifi was enabled in the stock rom. Currently, I'm using the latest htc sense rom from modaco, I'd really enjoy hearing if enabling wifi helps others extend their battery life.

your having better battery life with the Desire ROMs? that odd, my battery life with a Desire ROM was 20-30% worse compared to stock.

amlwaycooljr said:
Basically, when I leave wi-fi on my phone has incredible battery life. If someone has already mentioned this feel free to bury this post, but to my knowledge it doesn't seem this has been posted yet.
With wi-fi off and 3g on
- Battery lost 5-6 percent per hour
Wi-fi on
- Battery lost 1-2 percent per hour (sometimes less than 1 percent depending on what your doing)
Right now after having my phone on for 34 hours my battery is still at 70 percent! I'm fairly certain this is because it disables the 3g radio altogether which apparently is a real battery hog. That or maybe my phone is just a fluke. I really don't know.
This also seems to be tied to the htc sense rom (correct me if im wrong) but if i remember correctly battery drainage increased when wifi was enabled in the stock rom. Currently, I'm using the latest htc sense rom from modaco, I'd really enjoy hearing if enabling wifi helps others extend their battery life.
Click to expand...
Click to collapse
Actually, it's a well known fact that 3G uses more power on most (every?) phones than Wifi... so you're not alone.

Hey when you say WIFI on..do you mean WIFI and EDGE or did you completely disabled the radio?

I never would have thought having wifi on would extend battery life to such a great extent though, in most of the latest cell phone reviews and what not everyone recommends to have wifi off saves battery life but in this case just the opposite is true. I kinda knew the wifi was more efficient but I never expected such a large benefit from leaving wifi on all the time.
@ram130 I haven't actually touched the radios at all so I expect them all to be on or at the very least have edge on, I am able to receive and send calls and txt so I'm assuming at least some cell radio has to be on. All I did was use the htc sense rom and enable wifi.

The cellular radio is still on, but 3G/Edge (data) are disconnected. I don't know how Edge compares to Wifi, but 3G is a battery killer in comparison.

uansari1 said:
The cellular radio is still on, but 3G/Edge (data) are disconnected. I don't know how Edge compares to Wifi, but 3G is a battery killer in comparison.
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amlwaycooljr said:
I never would have thought having wifi on would extend battery life to such a great extent though, in most of the latest cell phone reviews and what not everyone recommends to have wifi off saves battery life but in this case just the opposite is true. I kinda knew the wifi was more efficient but I never expected such a large benefit from leaving wifi on all the time.
@ram130 I haven't actually touched the radios at all so I expect them all to be on or at the very least have edge on, I am able to receive and send calls and txt so I'm assuming at least some cell radio has to be on. All I did was use the htc sense rom and enable wifi.
Click to expand...
Click to collapse
In other words you have "use 2G networks" checked right?
I'm gonna try this is now. I'm currently at 3hr 32m unplugged with 80% left. I have wifi enabled and on the stock rom. So I'll post back when I wake in a few a hours and see how it goes.
My only problem:
Wifi seems to disconnect alot during the hour regardless if sleep policy is set to NEVER. My wifi signal is -78dBm to -86dBm in my room and on channel 11(used wifi analyzer). Any suggestions why?

I have the same experience at home, I enable Wifi and leave the phone stay home for a couple of days and battery still 40%, when I go out and wifi is not connected, 3G kicks in and battery drops much faster.
I'm using cyanogen 5.0.4.1

Interesting. Did not know this!
I guess I won't feel so bad about leaving my phone on Wifi all day!
Also, does anyone know how much power is used by not having a radio signal and letting it constantly search? That seems to destroy my battery. But sometimes I am in an area with wifi but no radio access (deep within a building).

It's too bad this phone doesn't have UMA - that would make up for T-Mobile's lack of indoor coverage (at times), and probably improve battery life a lot in some cases.
But I have to say that on another phones I've used, especially WinMo devices, using WiFi instead of 3G seemed to always use more battery. But, it could very well be different on this phone...I'm definitely going to give this a try.

im not sure about the percentage but i agree,the battery drain is considerably more when searching for radio.im in a building most of the day and it doesnt take long.miss the UMA i had on my bberry.
Paul22000 said:
Interesting. Did not know this!
I guess I won't feel so bad about leaving my phone on Wifi all day!
Also, does anyone know how much power is used by not having a radio signal and letting it constantly search? That seems to destroy my battery. But sometimes I am in an area with wifi but no radio access (deep within a building).
Click to expand...
Click to collapse

I also Get. About 25% better battery on wifi

Well after 10hrs of the phone being on stand by I woke up. It was at 46%!! my god. Anyway I checked my email, read an article all taking around 15mins and guess what? I had 30% left!. I put it back to stand by for 3hrs and took a look at it and had about 16% left...
It is now charging after one hour with just 10min use of downloading apps ..Can ANYONE tell me why my battery is draining so much on wifi? When its on EDGE for the night after 10hr I would have around 70% left from a full charge. Anyone can help me out here?
I shall be getting a replacement battery for free Tuesday.
Stock android.

ram130 said:
Well after 10hrs of the phone being on stand by I woke up. It was at 46%!! my god. Anyway I checked my email, read an article all taking around 15mins and guess what? I had 30% left!. I put it back to stand by for 3hrs and took a look at it and had about 16% left...
It is now charging after one hour with just 10min use of downloading apps ..Can ANYONE tell me why my battery is draining so much on wifi? When its on EDGE for the night after 10hr I would have around 70% left from a full charge. Anyone can help me out here?
I shall be getting a replacement battery for free Tuesday.
Stock android.
Click to expand...
Click to collapse
Did you set your phone to only use 2G networks also? If you're not charging, wifi will probably disable after not being used for a while..so it's probably rolling to 3G if you haven't disabled it.
I'm not saying it's convenient to constantly switch back and forth... but this explains why it may not be a good test of the battery life the way you're running it.

uansari1 said:
Did you set your phone to only use 2G networks also? If you're not charging, wifi will probably disable after not being used for a while..so it's probably rolling to 3G if you haven't disabled it.
I'm not saying it's convenient to constantly switch back and forth... but this explains why it may not be a good test of the battery life the way you're running it.
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Click to collapse
Well yes I have it on 2G only. Any thing else could be contributing to it dying so fast?

Well I found a way to use my laptop as an AP. So I connected my N1 to it and getting full bars(-41dBm) in my room now. No wifi disconnects so far!(maybe it was my linksys before ?).. So far the battery is at 86% with some 3D games, been unplug for 1hr 50min now. I'll put it to stand by now and see how it looks after 10hrs.
I'm on a stock firmware(not rooted). 2G only selected.

The way I understand it is as follows:
Phone is on STANDBY:
3g==2g* which are both more efficient then wifi (that's why the default wifi policy turns wifi off if it's not being used)**
Phone is ACTIVE:
wifi is more efficient then 2g/3g because:
1) It's waaay faster and thus causes less battery drain* and
2) The AP (router) is much closer to the phone then the cell tower so in theory it doesn't need to use as much power to talk to the router.
*http://code.google.com/events/io/2009/sessions/CodingLifeBatteryLife.html
4:45min into it there is a power usage chart and 3G/EDGE idle power usage is about the same - also somewhere else in the video they talk about wifi vs 3g usage when transferring data.
** http://code.google.com/p/sipdroid/wiki/NewStandbyTechnique
States that 3g standby is more efficient then wifi

drak0 said:
** http://code.google.com/p/sipdroid/wiki/NewStandbyTechnique
States that 3g standby is more efficient then wifi
Click to expand...
Click to collapse
Someone needs to test this ok. ...already testing wifi

Ok I'm at 11hrs 30min on wifi and its at 67% with light usage(checking email, news for 5min)..improvement? kinda, because since turning off my laptop it switched back to getting low signal(-81dBm) from the router in the next room. Weird? I'm still thinking. anyway I'm heading out so gonna use the phone more today, lets see if it gets me through the day.
Still no where near the thread starter 30hrs!! Maybe stock really sucks? bad battery anyone??

@ram130 I'm not sure how my battery is lasting as long as it has so far. I'm up to what would be an insane number, 65 hours 36 percent left .. this battery just wont die. I haven't the slightest idea how it's lasting this long I just leave wifi on all the time and turn wifi standby off. If anyone could explain how leaving wifi on more than quadruples my battery life I'd sure love to know.

low signal = horrid battery life!

at work today i guess i had a bad signal and i noticed i lost over 20% in less than 8 hours. whats the cause of this and is there a fix? i also notice the phone runs like **** on a low signal, very sluggish even when overclocked.

More power is bein pumped into the radio to keep the signal strong(er). Airplane mode is your friend. As for being slow, I don't know why but I also experience slowness in low-signal areas.

abcdfv said:
More power is bein pumped into the radio to keep the signal strong(er). Airplane mode is your friend. As for being slow, I don't know why but I also experience slowness in low-signal areas.
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Click to collapse
must be an android thing because i never had this happen with winmo or my palm pre.

Turn off 'Background Syncing' in Accounts & Sync settings. That will greatly improve both your battery life and phone slowness in low-signal areas. I have terrible signal in my work building too (would almost completely drain my battery in an 8-hour day), and ever since I started turning off Background Sync while at work, my phone only drops to around 50% in a work day.
I really think it's more the syncing that sucks the battery down in low-signal areas, not the radio having to broadcast stronger.

I have bad signal strength at my house. I also have a Airave to make up for this however since it does not provide 3g my battery will drop like mad when I am home.
The fix for this in my case is to turn off my mobile network when I get home that way I can still receive calls and texts but it basically tells the phone to quit looking for 3g signal and sticks to just the basics.
I then use my wifi while at home to get on the market or have my gmail and other apps sync with the phone.
Hope that helps you out and you find a solution that works for you.

I noticed MUCH moreso on CM6 vs. Fresh 2.3.3 what a significantly negative impact having background data enabled in a low signal area can have on the phone. My workplace is a consistently terrible cell area and since switching to CM6, I have been not only plagued with terrible battery life (like 10-15% per hour with minimal usage!), but the phone was running like absolute poo.
Today I checked to be sure and to my surprise, background data WAS enabled! I promptly turned that off and the phone returned to it's former CM6 glory and battery life returned to non-workplace goodness.

I have a bad signal at work, so I force it to roaming. It saves my battery and my phone is more reliable. Just be careful not to use too many minutes or too much data.

MrGreg said:
I have a bad signal at work, so I force it to roaming. It saves my battery and my phone is more reliable. Just be careful not to use too many minutes or too much data.
Click to expand...
Click to collapse
How do you set it to roam? Is this a setting or is there a code i can type in whenever I want it to only look to roam, then another when i want it to go back to regular, or even if i only want it to look for 1X or only look for 3G? One of the client sites i regularly travel to has great roaming 1X speeds once i can get it to switch to that but it must also have a weak roaming 3g tower somewhere because its always on 3g with one to zero bars.
I'm on Fresh though i'm apparently going to have to look into CM6 in the near future. I love this place.
Sent from my HERO200 using XDA App

ncadden said:
How do you set it to roam? Is this a setting or is there a code i can type in whenever I want it to only look to roam, then another when i want it to go back to regular, or even if i only want it to look for 1X or only look for 3G? One of the client sites i regularly travel to has great roaming 1X speeds once i can get it to switch to that but it must also have a weak roaming 3g tower somewhere because its always on 3g with one to zero bars.
I'm on Fresh though i'm apparently going to have to look into CM6 in the near future. I love this place.
Sent from my HERO200 using XDA App
Click to expand...
Click to collapse
You have a few options...
1. You are running Fresh on your Hero? Use the modded phone.apk from here: http://forum.xda-developers.com/showthread.php?t=745092
2. Use the PRL hack...you'll have to search for it, although I think the link is in the thread that I linked above
3. Download the app "Roam Control". Disclaimer, I am the dev, and yes it costs money.
4. Flash CM6.

Just recently stumbled upon an app called shutupbattery saver
It automatically kills your data when signal is low. You tell it what signal strength turns it off. Does wonders
Sent from my HERO200 using XDA App

markus_del_marko said:
must be an android thing because i never had this happen with winmo or my palm pre.
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Click to collapse
No..not really. I had several TP2 windoze phones since May of this year and went back to my Hero. The battery life on the RC1 build when you follow what has been said here,will give you way more life than any of the phones I have ever had.I was lucky to see 4 hours of life even with little usage with the TP2's. While my CDMA Hero does drop to 80% with everything turned on in 7 hours,it slows down considerably after that. Just with mild web crawling and 20 minutes of talk time it took well over 60 hours to drain completely last weekend after resetting the battery stats on mine with everything turned off. I actually had to use it non stop for 4 hours to drain the thing so it would shut off and be drained. Any phone I have ever owned has always done better after letting them drain completely and then charging them to 100% a few times. We have 4 of them in our home,and mine last longer than any of the others..the other 3 are stock 2.1.6 roms.
Mac

Why are people complaining about losing a measly, small 20 percent of battery in 8 hours? I'd understand if it was 35 percent or more, but seriously? you're complaining becuase your battery can last 40 hours? Wow...
CM6 RC1 with collin_ph battery tweak rules the world.

what i do to save my battery i change the settings on my advance task killer Menu>settings>Auto kill level(crazy)then also change Auto kill frequency(when screen off) and that really seems to help me

You could also look in to JuiceDefender. It shuts off 3g when screen is locked, turns it back on for either 1 min every 15 mins or 2 mins every 30 to sync.

jerry43812 said:
Why are people complaining about losing a measly, small 20 percent of battery in 8 hours? I'd understand if it was 35 percent or more, but seriously? you're complaining becuase your battery can last 40 hours? Wow...
CM6 RC1 with collin_ph battery tweak rules the world.
Click to expand...
Click to collapse
not everyone runs the froyo rom. at least i won't until a sense port comes out. and yes when the phone has a low signal it runs like absolute ****.

I'm having this problem also on CM6. Unplugged my phone this morning, full charge. Went to the gym at 11:30 and worked out for an hour and a half. There is no signal in my gym. The phone was completely dead when I got back to my desk. So basically the 80% battery drained in 1.5 hours (assuming I lost 20% between 7am and 11:30 when I went to the gym) It was not nearly this bad on the stock ROM. I just insggtalled collin_ph but I doubt that will help in this scenario. I might just have to remember to put it in airplane mode before going to the gym.
My bigger worry is when I'm out riding my road bike in the country. If I'm in the middle of nowhere, the battery will drain FAST... and thats the place I'll likely need to call someone in an emergency.

In my opinion there are key steps to insure a good battery life I perform this process every time I turn my phone on for daily use
First in settings/wireless/mobile networks I turn off data also roam and I change the signal to home only then in account and sync I turn off automatic sync and back ground data also i make sure that wireless is off as well then I turn my attention to applications and I clear data and force close any running program I'm not using for example gmail e mail browser Google search blue tooth I only force close apks that I know wont affect the system and how it runs also I should mention that this is done after I had calibrated my battery also I in spare parts I choose to make my end button put my phone to sleep these two steps are only done once now back to the process I run the over clock widget with dead3nce 9/14 stable kernel but also with every stable release he has put out I set the feq to 710 Max and 710 min and diff feq when screen off with 384 Max and 245 min this setup gives me high performance and long battery life I get 14 plus hrs with heavy use before ill hit 50% so u can imagine with moderate use will b or even standby time so I basically kill my phone if I'm not using it its in what I think is its lowest power state that I can get it at but its still on and ready so wen Im ready to use it I activate it and turn on what I need when I'm done I kill it again short of turning it off just thought I put this out in case it helps also I'm running cm6 rc1 and the 8/22 nightly I switch back and forth because of themes but the process is the same and so are my results so hope this helps good luck
Sent from my HERO200 using XDA App

It's 3G. Turn off your Mobile data when you going to be in an area with a bad signal for a long time.
As someone else said the collin_ph battery tweak works wonders too.

[Q] Crazy high cell standby killing my battery life?

Help!
I'm running the 81xx firmware on a direct-from-dell unlocked Streak.
My battery life has so far been abysmal, and looking at the battery usage screen, my cell standby is usually over 60% while idle is less than 20%, everything else like 2%. This isn't from weak signal, though; I am in a well-covered 3g-only area and my phone has reported only being disconnected about 4% of the time.
Another strange thing is, my data indicator is constantly switching between the H symbol and the 3g symbol.
Anybody know what's going on?

It might be that while you are well covered for 3g, you are marginal for HSDPA and that constant switching back and forth is using your battery. I have not tried it but have a look and see if you can disable HSDPA in settings somewhere and see if that helps.

i'm usually around 40% cell standby.. do u have any task killer apps installed? although people think those are useful they usually do more harm then good.

I have the same problem, and I used another Android phone in the same location (hence same cell coverage) with no such problems. I just took my phone off the charger and had the display on since then non-stop. Cell standby used as much battery as the display!! There's no way that is appropriate.
I'm running build 8102, but it was the same with 6941 before. Can't tell about 1.6 as I bought my streak used with 6941 on it.
What Android version are you guys running? Maybe we can find common denominators.. :/
Edit: here's a screen shot of the battery usage after a while off the charger with the screen on constantly:
http://i.imgur.com/3OrqZ.png

You must be Australian W0nk0
Do you think your antenna might be loose or defective?

I can't imagine the antenna to be loose really - but who knows, I bought mine used. If so, I think there is a signal strength value in " about phone" somewhere, no?
What signal strength are others getting? I'll post mine later, I'm on airplane mode right now so that I get some battery life.. :/

For signal strength, I am getting -75 to -95, and 9 to 12 for the two values while riding the train (not subway).
It also appears my battery life is quite good when my phone is in standby and not doing anything... the problem seems to come from net browsing or anything else that uses an active connection... Just browsng XDA is taking about 2% a minute!
Oh and my android is the 81xx 2.1 version with the modaco tweaks
Sent from my Dell Streak using XDA App

I had really high cell stand-by too. then i installed juicedefender, now my cell standby is down to about 29%.
I think the main thing is that it disables data connections while your screen is off and only turns it back on when the screen is on and unlocked. It also has a setting where it enables data connection periodically to allow background syncs and whatnot.
I'd recommend you guys give it a go, it had almost doubled my battery life!!

Mine shows,
cell stand by 50%
phone idle 44%
it seems quite common on the streak as I read in all the forums. I am on 2.1 stock rom? what's 1.6 like?

Using WiFi in the office instead of 3g for better battery life?

Well most of us have some sort of background data going on. I read some posts saying that it's actually better to leave wifi ON when in a coverage area so that way 3g won't be used for background data.
Can you share your experiences on this? To me it sounds a bit far fetched and even if its true, maybe it should be considered sort of a power malfunction that wifi would take less battery than 3g??
I wanted to try it out the other day and left wifi on during office hours, but ended up talking so much on the phone that dat that the result would not have meant anything... will try again maybe next week if I don't get and clear cut input.
Thanks in advance for any info
Sent from my HTC Vision using XDA App

100% True. If you are coming from another OS it might throw you. It threw me coming from windows.
It really saves battery. Try and see.

Huh? Nonsense!
Maybe if you put it in airplane mode (turn off the cell radio), but simple fact is that the more stuff you power up, the less your battery lasts.

I actually keep my WiFi on in the office and at home and believe I get better battery life (sleep policy set to never). No official tests, but I didn't use to get more than a day's worth of use before the switch. To be fair, I've made a lot of changes to my phone since then, so I don't know how much can be attributed to the WiFi change. You should definitely try it.
And I definitely don't believe it to be nonsense. The 3G radio apparently draws quite a bit of power and will constantly cycle for background syncs (which draws more power than a sustained connection for the same amount of data transferred). When the WiFi radio is enabled and connected though, the 3G radio is turned off. Depending on just how much power the 3G radio draws versus the WiFi radio and how much data you have syncing, it makes sense that using WiFi could save some battery life. The added bonus is that you use less data on your plan as well.
This might be different if you are using 2G though (since voice uses the same radio, it might be powered on the whole time anyway). No idea. Just have to try for yourself.
EDIT: Thought of another factor. Since WiFi will typically be faster, data is transferred for a shorter amount of time (perhaps drawing less power). The 3G radio also transmits data over a much longer distance than WiFi is capable of, which may cause it to draw more power as well.

And if your cell coverage is spotty, then the difference is even more pronounced. If you have wifi available, use it. You won't regret it.
Sent from my T-Mobile G2 using Tapatalk

This is indeed true, through experience i know it saves battery life, especially as someone said if your 3G coverage is patchy. The radio automatically adjusts its power o/p level depending on rx signal strength, so the o/p is more if signal is weak, therefore more batt usage. Also, it is worth noting that power is only really used when data exchange is taking place on wifi, so leaving it switched on, especially when connected does in fact save power, as when background syncing does take place, its done over a shorter period of time, again, saving overall power usage. The only time power usage goes up with wifi being left on is when out of range of an access point and the wifi is periodically checking for presence of an access point. I personally leave mine permanently switched on, and don't worry about it, it's more convenient that way.

Cell radio uses much more power when actually receiving or transmitting data, and much much less power when it is idling.
WiFi uses much less when sending/receiving data, but more power when idling.
Basically, your mileage is going to vary based on what apps you use and what apps pull down background data. If you've got a lot of apps that constantly use background data or you are constantly browsing the web on your phone, you will probably get more battery by using WiFi.
But if you disable most of your background data services and only use your phone every now and then, you will see much better battery life by just sticking with 3G.
edit: I also want to point out that the guy above me is, in fact, wrong. WiFi uses much more power than 3G when not exchanging data, even if it is connected to a network. The battery savings you're seeing is because every time your 3G radio goes from idling to transmitting, it uses an incredible amount of battery that completely offsets the idle usage of the WiFi.

I agree with everyone here, you will get better battery life with wifi because using the radio will drain battery faster when downloading. It is more efficient in pulling down data. I have mine almost on all day long in the office and at home. I do use the sleep policy, and very satisfied with the battery life on my phone.
Sent from my HTC Vision

Sorry to say but your just plain wrong. Try it out. The evidence is there. So is the documentation from users and google themselves. Its empirical man
dhkr123 said:
Huh? Nonsense!
Maybe if you put it in airplane mode (turn off the cell radio), but simple fact is that the more stuff you power up, the less your battery lasts.
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Sent from my HTC Vision using XDA App

xencor said:
Cell radio uses much more power when actually receiving or transmitting data, and much much less power when it is idling.
WiFi uses much less when sending/receiving data, but more power when idling.
Basically, your mileage is going to vary based on what apps you use and what apps pull down background data. If you've got a lot of apps that constantly use background data or you are constantly browsing the web on your phone, you will probably get more battery by using WiFi.
But if you disable most of your background data services and only use your phone every now and then, you will see much better battery life by just sticking with 3G.
edit: I also want to point out that the guy above me is, in fact, wrong. WiFi uses much more power than 3G when not exchanging data, even if it is connected to a network. The battery savings you're seeing is because every time your 3G radio goes from idling to transmitting, it uses an incredible amount of battery that completely offsets the idle usage of the WiFi.
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Check your information before correcting someone please, you may be right about the idle thing in terms of data transfer, although minimal, but the radio's on a phone don't switch between rx/tx like a walkie talkie does persay, but is in actual fact duplex in digital form, it involves syncronous timeslots and all sorts of complicated technical stuff. As I said before the main contributor to battery life hit on a phone is data exchange via high speed switch such as hsdpa/hsupa at weak signal conditions.

Clivectmob said:
Check your information before correcting someone please, you may be right about the idle thing in terms of data transfer, although minimal, but the radio's on a phone don't switch between rx/tx like a walkie talkie does persay, but is in actual fact duplex in digital form, it involves syncronous timeslots and all sorts of complicated technical stuff. As I said before the main contributor to battery life hit on a phone is data exchange via high speed switch such as hsdpa/hsupa at weak signal conditions.
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Uh, okay? I never said that part was wrong (in fact I agreed with it, although using different terms). I was specifically stating that your comment on WiFi using minimal power when idling ("Also, it is worth noting that power is only really used when data exchange is taking place on wifi") is completely opposite what is true.