The average smartphone run by the little green robot lasts for 5 hours and 38 minutes on a charge, but the average Android tablet stays juiced up for 6 hours 38 minutes. Neither of those runtimes equals a full work day, assuming you spend all day on the phone. You can add some time with a portable power pack, but those will cost you at least $20. Boost your battery life for free by following these 10 simple tips.

1. Turn off those wireless radios.

Just because you’re not using your device’s Wi-Fi, Bluetooth or hotspot features doesn’t mean they aren’t sucking up precious battery power. Flip the switch on those bad boys and you could save a decent chunk of battery life.

To turn off your Wi-Fi radio:

• Open your Android device’s Settings menu and select Wireless & Networks.
• Uncheck the box next to Wi-Fi, and your Wi-Fi antenna will shut down.
• Next, deselect the Bluetooth box to turn off your Bluetooth connection.

To disable your phone’s mobile hotspot:

• Open your device’s Settings menu and select Wireless & Networks.
• Select “Tethering & Mobile Hotspot.”
• Uncheck USB Tethering and Mobile Wi-Fi Hotspot to turn off both.

2. Turn off location services.

GPS and location services such as Google Maps come in handy when you want to find directions or search for local businesses, but they can also use up lots of juice.

Here’s how to turn off location services:

• Open your device’s Settings menu and select Location & Security.
• Uncheck the boxes for Google Location Services and Standalone GPS Services.
• Be sure to also uncheck the box for any proprietary GPS service, such as Verizon’s VZW Location Services.

3. Turn off background data.

Some Web-connected apps, email services such as Gmail and even the Android Market will continuously collect data in the background. Although convenient, this can put a serious strain on your device’s battery.

Follow these steps to switch off background data:

• Tap Settings and select “Battery & Data Management.”
• Press the Data Delivery tab and deselect Background Data.

4. Switch from 4G to 3G.

Switching from 4G to 3G when not using data-hungry apps or downloading large files can save you serious battery life. Unfortunately, the steps for switching from 4G to 3G differ from device to device and carrier to carrier. Below are the two most common ways to deactivate 4G data on your Android device. Note that if these steps do not work for you, your device may not allow for 4G to 3G switching.

• Tap Wireless & Networks under the Settings menu.
• Select Mobile Networks and press Network Mode.
• Select CDMA Only, and your phone will begin using 3G instead of 4G.

Alternatively, your device may allow you to disable 4G from the Wireless Settings menu. To do this:

• Tap Wireless & Networks in the Settings menu.
• Uncheck the box next to 4G.

The next time you access the Web, your device will tell you that it doesn’t have an Internet connection and then will immediately connect to 3G.

Certain devices also allow you to turn off your 4G connection in favor of a less power-intensive 2G connection.

To do this:

• Tap Wireless & Networks from the Android Settings menu.
• Open the Mobile Network Settings menu.
• Check the box next to “Use only 2G networks.” Note that you will be unable to access data while in 2G mode.

5. Zap haptic feedback.

Haptic feedback gives touchscreen keyboards the sensation of a physical layout through tiny vibrations. While this feature can make typing feel more natural, it can impact battery life.

How to disable haptic feedback:

• Tap Settings and select Sound.
• Tap Vibrate and select Never to turn off the Call Vibration function.
• Scroll down to Feedback and uncheck Haptic Feedback or Vibrate Feedback to disable feedback for soft-touch keys.

 6. Dim that display.

One of the biggest battery hogs on a mobile device is the display. That’s why dialing down the brightness (to a level that’s comfortable) is so important.

• Tap Display from the Settings menu.
• Select Brightness and deselect Automatic Brightness. This will prevent your device from varying the brightness based on the level of ambient light.
• Slide the brightness dimmer to the left until the display is at roughly 30 percent brightness, or whatever level is just bright enough for your needs.

If you really want to save power, you can move the slider all the way to the left. However, this will make it harder to view your display under bright lights and outdoors.

7. Set a shorter screen timeout.

Even with your display brightness turned down, your screen will still burn through your battery if it is left on for too long. Reducing your screen timeout is an easy way to conserve power.

• Select Display from the Settings menu.
• Choose Screen Timeout and select 30 Seconds.

8. Opt for a plain black background.

AMOLED and Super AMOLED displays provide users with deep, rich colors. Naturally, you’ll want to take advantage of that ability by sticking a colorful wallpaper on your home screen. But the truth is, the more colorful your wallpaper, the more battery life it will use. The same goes for Android’s animated live wallpapers. If your battery is on its last legs, you can change your wallpaper to a plain, black background. The less color displayed, the less power used.

Unfortunately, there is no default black background for most Android devices. But that doesn’t mean you can’t download one from the Android Market.

• Download and install the No Wallpaper app from the Android market.
• Once the app is installed, tap the Android Settings button from your device’s home screen.
• Select Wallpaper > Live Wallpapers.
• Scroll through the list of wallpapers and choose No Wallpaper. Your home screen will now be completely black.

9. Shut down instant messaging.

Google Talk and other instant-messaging clients can put unnecessary stress on your battery. Compounding that problem is the fact that Google Talk’s default setting automatically signs you into the app when you turn on your phone.

To disable automatic sign in, follow these steps:

• Open Google Talk and press Android Settings.
• Uncheck the Automatically Sign In box.

If Google Talk is already running, you’ll have to sign out and close the app. To do this:

• Open Google Talk.
•  Tap the Android Settings button and press Signout.

10. Disable automatic updates for widgets.

Live home screen widgets, such as those that provide automatic news and weather updates, get their information by pinging a corresponding website. Some widgets allow you to disable automatic updates, while others have to be removed entirely.

To disable a widget’s automatic updates:

• Open the widget and press your device’s Settings button.
• From here, you should be able to update frequency. For example, the news and weather widget on the LG Nitro allows users to set the update interval from manual mode to as frequently as every 15 minutes.

If you can’t adjust the widget and it’s something you can live without, we suggest deleting it from your home screen. To do that:

• Long-press the widget until it is highlighted.
• Drag the widget to the trash can icon to remove it from the screen.

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