Battery Boosters

Digital Camera Tips

Illustration: Otto Steininger
Turn off the flash: Those bright bulbs eat up power, and turning off the flash may give you dozens of extra shots. Bonus: Some indoor shots look better with the flash turned off, because the camera captures the ambient lighting instead of adding potentially harsh light from the flash, which can make a photo look overexposed.

Turn off the LCD: It may undercut the purpose of having a digital camera, but if you need to maximize battery life, looking through the optical viewfinder--if your camera has one--instead of ogling the LCD screen can save quite a bit of power.

Play images back elsewhere: We all tend to watch video or idly view photos on a camera or camcorder, but this eats up a substantial amount of battery life. Put off reminiscing about your vacation until the vacation is over.

Update firmware: Many digital cameras allow you to update their firmware. If you haven't done so in a year or more, it's a good idea to check whether an update is available on the camera manufacturer's Web site. Many firmware updates include upgraded power management options, which can extend your unit's battery life significantly.

Buy a bigger camcorder battery: Commonly you can get a bigger, longer-lasting battery than the one your camcorder came with--just be prepared to tote more weight, typically 5 or 6 extra ounces.

In This Article:

Why Don't My Batteries Last Long Anymore?

Rechargeable batteries are tricky little beasts composed of electrodes and electrolytes formed from assorted compounds such as lithium ion and nickel metal hydride.

As a side effect of the chemical reaction taking place inside, batteries heat up during operation, which causes the electrolytes to bend and warp. Recharging a battery reverses the chemical reaction, but it doesn't straighten out the plates. When a battery is used over and over, the continued warping starts to affect the chemical reaction, reducing the maximum charge the battery can hold.

Lithium ion batteries can typically survive up to 500 full discharges before losing enough of their maximum capacity to require replacement, but this depends on dozens of variables, including the battery's normal storage temperature. For example, leaving batteries in a hot car for an extended period could render them useless within about three months.

Voltaic Messenger

Photograph: Rick Rizner
You're carrying a bag or backpack anyway, so why not choose one with solar panels that charge your gear while you trek? When the next big blackout hits, you'll be prepared. ($239;

Juice Up Your Laptop

Battery Slabs by Hi-Capacity (top) and Valence can extend your notebook's running time.
Battery Slabs by Hi-Capacity (top) and Valence can extend your notebook's running time.
If you need 5, 8, or even 12 hours of computing time untethered to an electrical outlet, invest in a slim battery slice that rides beneath your notebook and greatly extends your laptop's running time.

These notebook battery extenders contain anywhere from 80 watt-hours to 300 watt-hours of additional juice, courtesy of lithium ion or lithium polymer cells. Depending on how much power your machine consumes, adding a battery slice to your notebook's internal battery could give you 3 to 10 hours of extra running time without a recharge. The slab plugs into your laptop's power port.

We tested Valence's $250 N-Charge VNC-130 and Hi-Capacity's $170 PowerPlus 60. The N-Charge weighs 3 pounds and provides 120 to 130 watt-hours of power. On a Dell Inspiron 710m, that translated into an extra 5 hours, 49 minutes of running time; and on an ultralight model, the Sharp PC-M4000, we got an extension of 9 hours, 8 minutes. The PowerPlus 60 weighs 1.2 pounds and provides 60 watt-hours of juice. In our tests, it powered the Dell laptop for an extra 2 hours, 40 minutes, and the Sharp model for an additional 4 hours, 33 minutes. The battery you select should depend on the running time you need and the extra weight you can carry.

Notebook PC Tips

Illustration: Otto Steininger
Tweak the power manager: Check the Power Options control panel (or your laptop's power management utility) and configure the settings on the right side of the pane, under 'Running on batteries'. How aggressive you want to be about power savings is a matter of choice. In general, the lower you set the intervals at which your monitor and hard disk turn off or go into standby, the more power you'll save. Don't set your hard-disk or standby time too low, however: Your PC expends power (and time) to spin up a hard drive, so make sure it shuts down only during periods of inactivity and not during brief pauses in your work. Turn-off times of 10 minutes for the monitor and 20 minutes for the hard disk should work well.

Go easy on the brightness: Every laptop has controls for lowering the brightness level, usually via a function-key combination. If you're in a dark setting, such as on a red-eye flight, you'd be surprised at how legible your screen is at 50 percent brightness. Nix Wi-Fi: You can typically add at least half an hour of running time by turning off Wi-Fi--and Bluetooth if your laptop has it. Idle Wi-Fi can be a security risk, too: Any open directories on your PC could leave the door ajar for snooping types in the area.

Take out unused components: Your removable optical drives, PC Cards, and USB peripherals all consume power, even when they aren't in use. Simply disconnecting these components--even if you slide the PC Card out of its slot just partway--will improve your notebook's battery life.

Add RAM: This is one component you don't want to disable: The more you have, the more headroom Windows has to work with, which will help your machine avoid excessive hard-drive reads and writes. This way, your hard disk can idle more often and reduce power consumption. More RAM also boosts your computer's performance considerably--a double win.

Recycle Old Batteries

Batteries: good for gadgets, bad for the environment. While most people avoid dumping their used motor oil into the sewer system, only about 5 percent of rechargeable batteries get recycled.

Dead rechargeable AAs are among the most recyclable products you can buy. Lithium and nickel batteries can be melted down, the metal recovered, and their materials reprocessed into new batteries, with virtually zero waste. But consigned to a landfill, the metals in recyclable batteries can contaminate the soil.

All rechargeables should be recycled. Many retail stores (including Radio Shack) accept them. Check out or call 800/822-8837 for a drop-off location near you.

Note that standard alkaline batteries are no longer the mercury-laden monstrosities of 22 years ago. Today's alkalines contain no mercury at all. Because these batteries are less toxic, many battery recyclers do not accept alkalines, though your municipality may offer a way to recycle them. Check with your local government before tossing them in the trash.

Cell Phone Tips

Lock buttons down: Mobile phones take a pounding when they ride around in pockets and at the bottom of purses and briefcases. Often the result is accidental button presses, which can run your backlight excessively and even initiate accidental calls. These scenarios not only consume battery power, but they could also hike up your phone bill. Save battery power by locking the keys on your phone. Most handsets have a lock feature that disables button presses until you enter a specific code. If you can't figure it out from the phone menus, consult the manual, look on the phone maker's Web site, or call customer support.

Use airplane mode--it isn't just for airplanes: Many handsets offer an "airplane mode" or "flight mode" that turns off the internal radio yet leaves the organizer and other features intact. It's great for flying, but it's also a good battery saver if you can't or don't want to answer calls but want to check the time--such as when you're sitting through the last hour of King Kong.

Go easy on extras: Bluetooth, text messaging, games, music playing--all are nice features for your phone, but all are power hungry too. If your phone can't get through the day on a single charge, consider nixing Bluetooth or getting a separate device to handle your messaging, gaming, and music-listening needs.

Photograph: Rick Rizner


Plug one of these disposable, pocket-size capsules into your handset's power port for an instant recharge that delivers about an hour of extra talk time. Adapters vary by phone model. ($5 to $13;

ElectriLite Crank Flashlight Cell Phone Charger

Photograph: Rick Rizner
Crank the handle on this flashlight and cell phone charger hybrid (adapters included) for 3 minutes, and you can provide your handset up to 8 minutes of talk time. Keep cranking if you have to call technical support. ($25;

Stuff We Love: Battery Life Indicators

Built-in Notebook Battery Tools

Some batteries, such as this one from a Dell laptop, are designed with an exterior battery meter.
Some batteries, such as this one from a Dell laptop, are designed with an exterior battery meter.
Notebooks have meters detailing how much charge remains in their battery, but you have to boot up your system to see the power meter display. If you're fumbling around with a stack of cells, trying to find the one with the most juice, repeatedly shutting down and rebooting your machine is terribly inefficient. That's why we appreciate the way some notebook vendors, including Dell and Gateway, have designed their batteries with a small battery meter right on the case. You simply eject the battery from the notebook and press a button: A set of LEDs will then light up, roughly indicating the amount of charge remaining. This approach isn't perfect, but it's far better than the blank face most batteries present.

Sony's InfoLithium Battery

Sony digital cameras estimate the time remaining in the battery.
Sony digital cameras estimate the time remaining in the battery.
What's the difference between one bar and two bars on the little battery icon found in many electronics? We haven't got a clue, and so we admire what Sony has done with its InfoLithium camera batteries: Turn on most Sony camera models, and you'll see an estimate of the amount of time remaining (in minutes) in the battery, instead of a cryptic icon. How does it work? InfoLithium batteries transmit information about the rate of consumption and other data to the camera, allowing the processor to calculate the amount of power left. However, Sony cameras may not function with third-party batteries, and older models sometimes mistakenly conclude that a fully charged battery is dead, possibly because the camera firmware isn't up-to-date.

Audio Player Tips

Avoid skipping: If you use an audio player with a hard drive, you can save quite a bit of its power by selecting a playlist and then letting the device play uninterrupted. Because hard-drive players buffer songs in memory, they don't have to read continuously from the disk. Reshuffling tracks, skipping ahead, rewinding, and pausing the music require more reading operations, all of which consume more power.

Play smaller songs, get longer life: Your player will last longer playing 1000 5-minute songs than five 1000-minute songs, because with shorter songs the device loads full tracks into memory, reducing the need to access the hard drive. Break long songs into multiple tracks, or compress them at a lower kbps rate.

Do away with the backlight: Disable the backlight or set it to turn off quickly. The less light you use, the more tunes you'll hear.

Keep it cool: Batteries work via chemical reactions (see "Why Don't My Batteries Last Long Anymore?" for more), and extreme temperatures can make batteries work harder to generate the same amount of power. Thus, Apple recommends keeping your iPod running at between 32 and 95 degrees Fahrenheit, and specifies 72 degrees as the optimum temperature. Remember, a leather case can act as an insulator, increasing a device's risk of overheating.

Ignore the equalizer: Tweaking the bass or the highs makes a player's processor do extra work to alter the sound. Set the equalizer to off or to zero decibels to maximize the playing time.

APC Auto DC to AC Inverter

APC's Auto DC to AC Inverter.
APC's Auto DC to AC Inverter.
Plug apc's converter into your car's cigarette lighter, and you're good for up to 350 watts of power. It won't add much weight to your bag, either--about 3 pounds. ($40 and up, depending on wattage;

Up Next: Eco-Friendly Batteries

For all their compactness and convenience, batteries as we know them may soon become obsolete. Fuel cells in various shapes and sizes have been in the works for decades, but technological hurdles and regulatory issues have prevented products from coming to market. Now, researchers may be nearing a solution that works for mobile devices.

In simple terms, fuel cells convert molecular hydrogen (inside the cell) and oxygen (in the air) into water, which they release back into the air as vapor. The by-product of this reaction is electricity. The basic chemical reaction resembles the one in a battery--involving anodes, cathodes, and electrolytes--but with a few improvements. Instead of requiring recharging via electricity, which is inefficient, a fuel cell uses up its hydrogen store and can then be immediately refilled, much like a butane lighter, with no "recharging" required. Also, pound for pound, a fuel cell can outlast a fully charged battery. And theoretically a fuel cell causes no pollution.

Today most research on fuel cells has focused on methanol as the source of the cells' hydrogen, and a number of large companies--including Hitachi, NEC, and Toshiba--have constructed prototype cells that are designed for mobile devices and use liquid methanol as fuel. But the companies involved have elected to delay launching the technology until 2007, in part due to government regulations about traveling with methanol.

Fuel Cells Coming Soon

The first fuel cells to arrive in stores will likely be in Medis Technologies' Power Pack, which is designed to recharge cell phones and other portable devices and is beginning limited production this year. The pack uses a borohydride-alkaline solution combined with alcohol--which, unlike methanol, is approved for airplane use--but the cell is not refillable, and some financial naysayers assert that the Power Pack is not a true fuel cell because it isn't refillable.

Power Packs should be available at retail stores by this fall. For $12 to $20, a single Power Pack will provide about 80 hours of running time on an iPod or nine full charges of a cell phone, Medis promises.

Which AA Battery Lasts Longest?

We lab-tested four types of AA batteries to find out which could stand up best to the heavy demands of today's cameras. Energizer's e2 disposable lithium cells lasted longer than other AAs in our tests. Compared with Duracell's Ultra M3 Alkalines (which we used as the baseline), the lithium batteries delivered 3.3 times the number of shots in a point-and-shoot camera and 2.7 times the shots in an advanced camera for twice the cost. Overall, results were similar between the two-battery Canon and four-battery Fujifilm cameras.


Price for four

Camera type

Number of shots

Battery life

Energizer e2 Lithium



664 photos

365 minutes

Advanced Camera2

785 photos

431 minutes

Energizer Rechargeable NiMH 2500 mAh



476 photos

262 minutes

Advanced Camera2

549 photos

301 minutes

Panasonic Oxyride ZR6XA



224 photos

123 minutes

Advanced Camera2

331 photos

182 minutes


Duracell Ultra M3 Alkaline



198 photos

108 minutes

Advanced Camera2

282 photos

155 minutes

FOOTNOTES: 1We tested two AA batteries using Canon's PowerShot A520. 2We tested four AA batteries using Fujifilm's FinePix S9000. 3$26 with battery charger.

Christopher Null is a San Francisco-based technology writer. Testing was designed and performed by Tony K. Leung and William Wang.

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