Wifi sleep policy

This tip is one that seems counter-intuitive, but you can save a lot of wear and tear on your Android phone's battery if you tell it to keep the Wifi radio turned on and connected while the phone is sleeping.  Your phone needs a lot of juice to keep pinging those cell towers, and even more to transmit data to and from them.  Wifi radios use much less power because of their design, and they don't have to keep searching for a better access point.  It's the way cellular data communication was designed, and it's a necessary evil.

But what if you're spending all day (or all evening) in one place, connected to Wifi?  If you tell your phone to shut off Wifi when idle, it bounces back to cellular data (be it 2G, 3G, or 4G) and starts sucking down the electrons again when the screen shuts off.  That's no good, and easy to fix:

  • Open the advanced Wifi settings by pressing the menu button, then Settings, Wireless & networks, Wi-Fi settings, and tapping the menu button again.  You'll have a choice to either Scan, or go Advanced -- go Advanced.
  • Tap the Wi-Fi sleep policy entry, and you'll get a pop up dialog with the choices you see in the picture above.  Choose Never.

Now even when your phone goes into standby mode, you'll stay connected to Wifi and be able to get mail and messages without turning the cell radio back on and trouncing your battery life.  And for the times when you're not in an area with a Wifi connection, just shut Wifi off, either through the menu or with a handy toggle widget.  Your battery will thank you for it.

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Reader comments

Android 101: Save battery by keeping Wifi alive

46 Comments

I wonder why this setting isn't on by default. It says when you turn it to the never setting that there may be more battery drain but actually the opposite is true.

It was on by default on my father's Thunderbolt. (He wanted me to load his music on the thing... I made some other minute tweeks.) It was quite the surprise for me that HTC (or Verizon's techs... not sure which) did that. Wasn't on my Droid OG or my mom's Droid X.

There may be some confusion about this setting because not all android phones are set up the same. My phone (Samsung Nexus S) says "keep wifi on during sleep" so the proper box to check is "Always" which IS THE DEFAULT SETTING. The author of this article has an android which addresses this setting from the opposite direction and asks if you want your wifi to turn off when sleeping - which the answer is "Never". If I checked "Never" on my phone, according to this article, it would cause more battery drain. Just thought that in would point this out so that people pay attention to which direction the setting is being addressed. The above poster may have an android which addresses the setting from the same direction as my phone.

Thanks, just got a new Samsung android phone, so your reply reassured me that I had the correct setting. People new to devices DO it nervous about these things. I know I was getting a bit confused when reading about the settings as you suggested. Glad your post from almost one year ago, was still up.

This is a great tip. I never understood why you'd want to turn off wi-fi in standby unless you were turning off all data altogether, e.g. airplane mode.

Thank you for posting this. I had forgotten how to do this and it bugged the crap out of me to have to wait for my WiFi to reconnect every time I would bring my phone out of sleep. Pretty much the only time I am not on a WiFi connection is in my car on my commute. Even then I have found enough open networks to have a connection almost the entire way home.

This may be true if you are always in an area with WiFi. But beware and make sure you turn off WiFi when you leave your house. When the WiFi radio is searching for a connection, particularly on the Thunderbolt, it uses a huge amount of power. So while you are driving around, you'll find your phone drains the battery quickly if leave WiFi on. I use the Auto WiFi Toggle app to minimize battery usage. It turns off WiFi when it disconnects because you got out of range of your WiFi, and then turns it on every 15 minutes for a second or two to check for a new connection.

Ahh, the beauties of having a DINC2.

I routinely put my phone on the charger at night with 30-40% battery and I have never turned my WiFi off.

Actually, I seldom turn wifi off EVER. It costs very little in terms of battery drain to leave it on on my Nexus One or Captivate, or even on my long-ago iPhone.

It just listens for a beacon it recognizes. Receivers cost very little in power. If it doesn't recognize the wireless routers, it knows it can't connect, so it never uses the transmitter side of the chip.

Navigation is better with wifi on, especially in a city where there are lots of wifi routers in Google's database.

It might be something specific to your phone. I just don't see any significant battery drain with wifi on vs off.

"I just don't see any significant battery drain with wifi on vs off."

It's certainly one of the bigger "battery drain" myths.

I never knew about this, but just checked and mine was set to never sleep by default.
I have a stock HTC Evo 3D.

You may also want to check the box next to Best Wi-Fi performance which is right below the Wi-Fi sleep policy on the Evo 3D.

Don't ask me what it does but it's gotta be something good since it may consume more power, right? LOL Seriously I check it.

Y5 from the market is a handy app that goes well with this tip.

It automatically turns on your wifi radio when you are nearby a wireless network that you have previously connected to. Then when you leave the area, Y5 knows this and turns your wifi off for you automatically.

It's a great little app. Now I never have to worry about turning on and off my wifi to save battery. Y5 does it for me.

https://market.android.com/details?id=pl.polidea.y5&feature=search_result

Are you sure this saves anything?

It substitutes running your GPS for an idling wifi receiver. How can that be a good trade off?

Y5 depends on the network location mostly which uses much less power than the actual GPS, I use the same program and yes it saves power, maybe slightly less than if you did it manually, but you still save a lot of power and don't have the trouble of toggling wifi on an off all day. Before I found this program I never used wifi, I knew it saved power and I couldn't be bothered to turn it on and off constantly.

I don't understand what you mean by the network location?

If wifi is off, that only leaves cellular towers for determining network location. But since cell towers cover a radius of 15 miles, that means there are 700 square miles where it would leave wifi ON just on the chance you might get near a Starbucks you have visited before.

Have you actually just TRIED leaving wifi on without this app running and doing some comparisons for a few days?

After all, you said yourself you never used wifi before you got this program, so how can you know if it really saved you anything at all?

This sounds a lot like the Tiger prevention rock someone sold us a few years back. It works great. Not a single Tiger in all these years.

Network location is provided by the cellular network (triangulation from nearby cell towers). A much more coarse location than WiFi and GPS. Since your cellular radio is on anyway may as well use this data.

I think you misunderstood how Y5 works. Using network location data, Y5 will remember the location of wifi networks you have connected to before. Then when you leave that area, your wifi connection drops, and Y5 will recognize this and disable your wifi radio.

Once you're near an area where you connected to a hotspot before, Y5 will recognize this and then enable your wifi radio. So it doesn't matter if you're more than 15 miles away from a cell tower, as long as you have cell service, Y5 knows where you are and can toggle you're wifi when you are close to a wifi network.

Why would you want wifi on and looking for a signal (and wasting battery) when there is no hotspot? This saves me tons of battery, and it saves me time so I don't have to constantly turn on and off my wifi when I walk in or out of range of a hotspot.

This is really good advice, that many people get confused and think it NEVER would save battery.

Heck it even says so on many versions of Android where the sleep setting has text that specifically says that NEVER will use more battery.

This leads many astray, because while it might save battery if your phone/tablet does NOTHING while it sleeps, that is NOT how we use our devices. Most of us have stuff running on our phones 24/7.

But when wifi sleeps, every mail check, facebook, check, google talk connection, has to be re-established over 3G. Whereas with a wifi connection, your phone can essentially close its data channel on 3G, drop to GSM only for phone and text messages. Way less power.

Even on Wifi Only Tablets NEVER will save battery, because without it, every mail check has to use polling, wake up the radio, negotiate a DHCP address, establish a connection, contact the mail server and ask for any mail. Whereas, with NEVER, Mail (especially Gmail and Exchange and most Imap) simply keeps a socket open, and lets the wifi drop to a low power state. When the socket becomes readable because mail arrived it simple resumes full power and reads the incoming mail.
Way more efficient.

Great explanation. I always just figured that WiFi was more battery efficient because when phones are given their battery life tests (* hours browsing on 3G/WiFi) WiFi always had longer browsing times. 3G/4G is cool when you're out but WiFi is superior in almost every way except that you have to stay in range of your router.

the goodnight app keeps my phone from disturbing me with sounds all night. It only lets thru selected numbers. It's a must for me.

I wish. If I leave wi-fi on the phone is dead in 2 hours. I have a program that automatically turns off wi-fi and mobile data when it goes idle. That alone extends my battery to 8+ hours of normal use and more if it sits there idle. I can forget about the phone and still have juice the following day. I have a HTC Thunderbolt.

If your phone dies in two hours with WiFi on, then you have a defective phone. Take it back and get it replaced. That is not normal for a Thunderbolt.

Guess it was just me, but when I had my N1, I had set the WIFI radio to never sleep, and, well, it killed my battery faster, like 10% an hour. Putting the WiFi back to default (sleep when screen is off) allowed me to make it a full day+ again.

Guess what I'm saying, is try it both ways to find the mode that works for you. :-)

(I don't run a lot of data intensive apps, so that is probably why my results are opposite of those here. My only apps are Email which checks every 30 minutes, Weather which is once an hour, and news, which is once every 4 hours. And my only push app is Good for Enterprise.

With that usage, it's more efficient for the phone to wake up the 3G, send it's 1K of data, and go back to idle.)

It's a coincidence that I did this earlier today, in the morning. I had factory reset my phone a while and wondered why it would disconnect to 3G, and wondered if I did something wrong then remember this setting.

I use an Elixir widget to keep 3G data access off unless I need it, and around the house, I have constant Wi-Fi access. So it makes more sense for me to have Wi-Fi turn off when the screen is off, since there is no data access most of the time, there is no battery cost there. That way, when I leave the house, I do not have to remember to turn Wi-Fi off.

My only concern is that Wi-Fi and Bluetooth are not necessarily the best friends in the world and I for one truly hate taking phone calls phone-to-ear, so I always keep Bluetooth on with a BT headset connected. I'll give this tip a try and will report if I get more Bluetooth-vs-WiFi conflicts out of this.

EDIT: WOW, this actually helped A LOT! Excellent tip. As for Wi-Fi+Bluetooth woes, it doesn't seem that bad -- only when Wi-Fi loses its signal it interferes somewhat with Bluetooth but as long as you don't venture too far from the hotspot, no issues.

This was a great article, I started using this along with Auto Wifi Toggle, and the results so far have been great, 12 hours on and still at 80%, while the phone was in pretty much standby for the first 6 hours, it stayed at 99%.

Why have a smartphone?

Among other reasons to get email, and how smart is it if you have to keep checking it manually? not very, and how much use is push mail when the darn wifi keeps going to sleep? none! none at all!

That's why this tip saved me from slamming my "smart" phone against the wall in total frustration.

But awesome tip = awesome phone, cheers dude :-)

thanks for the TIP i was a blackberry user and then i switched to android, one day i noticed my mb in my data plan were over, same mbs i had with blackberry, some guy from the phone company told me it was because android consumes much more data than BB and turning WiFi off certainly didn't help too much. Thanks for this post, it saved my day, now i can keep WiFi on all the time and use 3G only when i am out on the street.

Hello. I have a confusion about this matter. I don't always use 3g, so i don't always keep 3g on. When i need it to run, i just set it on manually. However, I have Wifi connection at home and when i'm at home, i set wifi on, and when i'm out, i just turn wifi off manually. Now here is the question: Is it useful for me to set the sleep policy option to "never", or will it be more battery saver if i leave it as it is?

Thanks.

does not actually work. I use an Atrix 4G and these directions are spot on for my andriod. It wasn't until I repeated the steps that I realized that I had already chosen "Never" for my WiFi to stay on. Yet, it's still always cutting off when my screen goes idle. So, I thought my battery saver app was overriding my phone settings so I went to my app and checked settings there. Settings are set for my app to not be able to enable & disable Wifi at it's own convenience. I uninstalled the battery saver for a while and my Atrix still disabled WiFi when the phone goes idle.

I have the android samsung sgh 1727....when I set my wifi to NEVER....it reverts back to ALWAYS....? Can anyone help with this situation.

It all depends on the type of your phone or tablet and your location and movement pattern. I also thought WIFI should stay on, but my Galaxy Tab drained power very fast since I bought it.
After 1 year I enabled WIFI to sleep when the screen is turned off and now the standby time grows from 1.5 days to 5 days!!!
I don't care for the extra data because a have an unlimited plan.
My advice: Test your system and decide for yourself. Don't believe every pseudo-scientific explanation seen here ;-)

read with interest the tip on keeping wifi on during sleep. when I checked how my S3 is set up the question is 1)Keep wifi on during sleep- and the options are Always, When plugged in, Never.
So in that instance one would want to check Always.
thanks-good education.