Significantly increase your 4G Android’s battery life

Sounds like either a lie, or spam, right? Not so!
In the last week I have managed to triple the battery life of my Droid Bionic, with one Android setting and one simple app.

A word of warning: This method will work best if you are in areas where there are WiFi connections available. If you find yourself on the road or traveling around a lot, you may not have as much of a gain.

We’ll take a look a the major causes of battery drain in cell phones and then look at how we can eliminate them.

Why your battery life sucks
To understand why we can get better battery life, you have to understand why your battery life is so terrible to begin with:

  • Signal strength
    At home where I spend most of my time as a remote-employee, my signal strength is fairly weak. Under normal circumstances my phone can maintain 1-2 bars. This is pretty terrible. If you can maintain 4-5 bars of signal strength for most of your day your battery life gains may not be as impressive as mine. As your signal gets weaker, your phone has to use more power to maintain a good connection to the network.
  • 2G, 3G, 4G, WiFi oh my!
    • 2G is the technology by which all cell phones make digital phone calls. These protocols have been around since 1991 and continue to work well for the most basic phone functions. Enhancements to 2G such as EDGE and 1xRTT allowed data transfer speeds up to 115kbit/sec
    • 3G is a more recent technology which started gaining use in 2001/2002. 3G provides higher data transfer speeds, while using more power. There are many variations on how 3G is implemented, but data transfer speeds are required to be at least 2Mbit/sec for stationary users.
    • 4G LTE is the latest technology, offering significantly more bandwidth than before. 4G offers at least 100Mbit/sec for fast-moving users, and 1Gbit/sec for stationary or slow moving users. Of course this comes at the cost of significantly more power use.
    • WiFi, while not a mobile network, is the other option we have for data transfer. While in theory it is slower than 4G, in practice it can be at least as fast or faster than the current generation of 4G and uses far less power. The reduced power is due to the limited range at which WiFi networks can operate. While mobile networks have to be able to work over many miles, WiFi networks are far more limited and usually don’t extend far beyond 100-200ft (40-70m) in the best case.
  • Dual-mode and circuit-switched fallback
    There’s a problem with 4G. Phone calls are made over 2G and 3G networks, but can’t be made over 4G yet. Why not? Well, 4G is not widely available yet, and until a week ago there was no technology available to hand off calls between 4G and 3G/2G networks. So networks have worked around this in two ways:

    • Dual-mode operation is used by CDMA networks such as Verizon and Sprint. In this mode, your phone maintains connections to BOTH 2G and 4G networks at the same time. Yikes! This double-connection to the network is one of the primary reasons people on these networks have such problems with battery life.
    • Circuit Switched Fallback (CSFB) is a similar trick done on GSM networks such as AT&T and T-Mobile. When a call comes in, the phone is kicked off the 4G network and switches to 2G/3G for the duration of the call. Not very elegant, an this switching causes more power drain. If you take a lot of short calls, this can drain your battery even faster.

Extending that battery life
Ok, that’s all well and good, but how can we use this knowledge to extend the life of our battery?

In my case, and in the cases of the small (and probably biased) group of people I’ve spoken to, we found our phone use fell mostly into this pattern:

  • Heavy use at home or at work
  • Lighter use while outdoors or commuting

Whereas 4G uses quite a lot of power, it is also very handy to have for some quick browsing and navigation on the move. Our goal is to reduce dependence on 4G and take advantage of available WiFi networks around us. Ideally, we want to have the WiFi network connected all the time. On an android phone, this can be achieved by going to your Settings -> Wireless & network -> Wi-Fi settings. From here, tap the Menu button and choose Advanced Settings, and change your Wi-Fi Sleep Policy to “Never”. This will cause your Wi-Fi connection to stay on permanently.

Now some of you many have already noticed that being connected to a WiFi network causes your phone to lose power FASTER not SLOWER!

Very true! There is one more crucial step.
Open the Android Market, and search for an app called DataSwitch by TomatoX.
DataSwitch is a wonderful application, which allows you to completely disable and enable your 3G and 4G connection.

As you have your phone using your available WiFi connections, you have no need for a data connection to your mobile network. Each time you run the DataSwitch app, it will enable or disable your mobile data connection.

Final results
Using this method I was able to extend the life of my battery from a typical life of 15 hours on 4G, to 45 hours. Quite a gain!