# A "hallelujah" battery improvement



## rouftop (Aug 17, 2011)

I spend 90% of my time in a WiFi zone. As such I've always made sure to enable WiFi to get the best battery, because as we all know WiFi drinks up far less juice than mobile data. But what I didn't realize is that by default the WiFi connection will disconnect when you turn off your device. When that happens your phone will connect to mobile data if it hasn't been explicitly disabled. And if you have 4G enabled... there's where your battery is going.

There are two perfectly good solutions to this problem. One is to drop down to 3G when you are connected to a WiFi network, using a toggle or whatnot. That alone will save you tons of battery. Another solution is to disable WiFi sleep altogether. This setting is remarkably well hidden, here's where to find it (for AOSP-based ROM's at least):


Navigate to Settings => Wireless & Networks => WiFi Settings
Press the MENU button (talk about intuitive!)
Choose "Advanced"
Set the WiFi sleep policy to "Never"


In my case I always kept the 4G connection enabled, since in my mind I wasn't using it. My phone would be half-dead by lunch, and out of juice completely well before bedtime. I was getting a total of 12-13 hours max. But after disabling WiFi sleep, I've only used 30% of my battery after > 7 hours off the charger. That's not quite a 100% improvement... but it's enough to finally make it from dawn to dusk without recharging. And it's WAY better than anything I noticed from switching ROMs or kernels.

I haven't done any kind of measurement to see which uses less power (3G or WiFi) but maybe somebody else can chime in. (For that matter, how much power does 1x use? I'd gladly drop all the way down to that for extra juice if my phone is off anyway!)

I expect that a lot of you already knew this, but I bet there are others out there who don't. If you are wondering where your battery is going when you're sitting at your desk with your phone in your pocket, see if this is your issue.

And of course, only enable 4G when you know you need the speed!

Full specs: Liquid Thunderbread 2.6, Tiamat 1.1.1 .


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## Bindy (Jul 16, 2011)

That's one of the first things I do when I flash a new ROM.


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## cam30era (Jul 25, 2011)

Reportedly wifi uses less battery than 3g > http://m.androidcentral.com/android...mpaign=Feed:+androidcentral+(Android+Central)


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## barcodelinux (Jun 19, 2011)

It has been my experience that wifi uses far less battery than any form of mobile data (1x, 3G, or 4G).


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## deltaechoe (Jul 20, 2011)

Just turn off mobile data when you aren't using it


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## FSRBIKER (Jun 9, 2011)

There are battery apps that will toggle on/off your data connections when in standby mode saving battery but still allowing you to receive email, twitter/facebook/etc updates as well.


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## orkillakilla (Jul 9, 2011)

Green power will do all you need

Sent from my HTC CyanogenBolt powered by CyanogenMod 7 RC1.6.1


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