How to Improve Battery Life on Any Gadget

The lithium ion batteries in our phones, laptops, cameras and MP3 players never seem to last long enough. But there are plenty of small adjustments you can make to make sure batteries don't run down quite so quickly. Here's a complete guide to improving all your gadgets' battery life.

These days, we ask a lot of our gadgets. They, in turn, ask a lot of their batteries. And while the lithium-ion batteries that power most of today's mobile devices are an improvement on the ones electronics used to rely on (they last longer and don't have a "battery memory" effect to worry about), having a laptop expire midflight is still frustrating. Short of any chemistry breakthroughs, our batteries won't be getting much better anytime soon. That means it's up to us to stretch their abilities as far as possible.

For just about any lithium-ion-powered gadget, there are a few basic rules that should help with battery life. First, try to avoid extreme hot or cold temperatures—these conditions can limit the charge. You'll also want to go through at least one charge cycle a month. A battery won't lose its charge as quickly if you keep its electrons moving. If you know it's going to be a long time before you use a gadget again, run its battery down to a bit under half of the maximum charge and leave it in the fridge (but never the freezer). And for many electronics, downloading the latest firmware from the manufacturer's Web site can provide better battery management.

Phones

Modern mobile phones are communication addicts. Even when they aren't making calls, they are constantly pinging cell towers, searching for networks and grabbing e-mail from the data cloud. All these connections use a lot of power. So turn off your phone's Bluetooth when you aren't using a wireless headset or transferring data, turn off its 3G connection and Wi-Fi when you aren't surfing the Web or using data-intense applications, and turn off the GPS receiver when you aren't trying to pinpoint your location. And while smart phones such as the iPhone can continuously check for and download new e-mails, each of these check-ins uses power. Turning off this "push e-mail" and pulling your messages manually (and less frequently) will stretch your battery life.

Other preventable phone-battery wasters: the speakerphone, the "vibrate" function and anything that uses the phone's processor or screen, such as pictures, music, movies and games. Keeping the key lock on can prevent accidental in-pocket button pushes from wastefully turning on the screen's backlight.

MP3 Players

If battery life is important, opt for an MP3 player that stores its data on flash memory. Hard-drive-based players usually hold more songs, but they also have more moving parts, which translates into shorter battery life.

You'll also want to adjust a few key settings. First, set the backlight timer, which controls how long a screen's backlight stays on after a button has been pressed, to the minimum time available. Then make sure the sound equalizer (called simply "EQ" on iPods) is turned off—that added bass boost doesn't come for free. However, if you're using an iPod and made changes to a song's equalizer preset within iTunes, this won't help. In this case, switch the EQ setting to "Flat."

And as tempting as it is to song-surf, it's more efficient to simply let a playlist or shuffle run without skipping. Not only does jumping tracks trigger the screen's backlight, but it also calls the player's processor (and hard drive, if it has one) into service. And, with some MP3 players, sticking to shorter songs can save power. The iPod, in particular, uses a memory cache to store upcoming tracks. This cache is designed to work most efficiently with music files that are smaller than 9 MB.

One last point: Most MP3 players face substantial power penalties when they play tracks with antipiracy digital rights management built in. This is because it takes processing power for the players to decrypt the files. So stick to simple MP3s when possible.

Cameras

Auto-flash and autofocus functions allow anybody to point and shoot with just about any camera. However, these crutches are battery-busters. Cutting back on your use of a camera's flash and autofocus won't just allow you to take more photos between charges, it will also make your shots more interesting. So try manually adjusting the focus (assuming your camera allows you to). And instead of using a flash, increase the camera's light sensitivity by raising the ISO setting, or adjust the exposure manually, if you can.

Still, a camera's single biggest battery-burner is its LCD screen. Framing your shots with the optical viewfinder (assuming your camera has one) can yield massive power savings. Likewise, fight the temptation to repeatedly review your shots on the screen.

Laptops

First stop: Your laptop's preprogrammed power-saving settings. These save juice by trimming down on a computer's internal activity, typically by minimizing the unnecessary use of its processor, screen and hard drive. To find these settings in Windows Vista, go to your computer's Control Panel and click Power Options, then Power Saver. For Macs, click into System Preferences and then Energy Saver. You can even create a custom setting that will save more energy by cutting power to these components after they've been idle for as little as 1 minute.

The optical drive is one of the biggest bandits. Instead of watching movies off of DVDs, watch them off your hard drive. Another culprit: external components, particularly powered USB gadgets that piggyback off your laptop's battery. If battery life is a concern, stick to a laptop's own keyboard and trackpad.

As with other gadgets, dimming a laptop's screen will save power. But you can save even more by turning the backlight off completely when it's not needed. Turn the brightness down until the backlight is completely off while you wait for idle tasks such as downloads and file conversions to complete.

You'll also want to turn off scheduled tasks and close applications that aren't in use—particularly ones that launch automatically at startup. And, as with anything with a wireless connection, kill the Wi-Fi and Bluetooth when you aren't using them.

Oddly, a battery doesn't need to be completely dead for a laptop to shut down—the computer just needs to think it's dead. Recalibrate the circuits that keep tabs on how much battery life is left by running the battery down completely and charging it back up. Do this every 30 or so charge cycles.