Technology

More Power to You

Learn how to keep your tech tools charged while on the road.

There you are, stuck in traffic, calling your client to explain, and your cell phone dies. While waiting for a weather-delayed flight, you catch up on e-mail correspondence - until your notebook nods off. Working in a restaurant between two client appointments, your personal digital assistant poops out. What's a weary road warrior to do?

You now can fit your office into a briefcase and work anywhere - or so technology marketers would like you to believe. But before taking your show on the road, make sure you know where to find your next watt.

The Facts of Battery Life

Freedom is finite in the mobile computing world. No matter if you've got the latest tablet PC or smart phone, you're only as good as your last charge. Rechargeable lithium ion, or Li-Ion, batteries power most of today's portable computers, cell phones, and PDAs. They are lighter and last longer than the nickel metal hydride, or NiMH, batteries that older laptops may use.

If you recently upgraded to a new notebook that uses Li-Ion instead of NiMH batteries, you should be aware of two differences. First, Li-Ion batteries last longer if they have 10 percent to 20 percent capacity remaining when recharged, unlike NiMH batteries, which must be totally discharged. So if you're in the habit of using your notebook until it dies, stop and recharge earlier.

Second, you can only fully charge NiMH batteries with your laptop turned off, but you can charge Li-Ion batteries while using your computer.

Batteries degrade from the moment they come off the production line, and Li-Ion batteries are more susceptible to aging than other types. Don't stock up unless you're going to use them regularly, and don't buy batteries too far from their manufacture date.

Heat and charge level greatly affect a battery's life, so don't leave a fully charged spare battery in a hot car. (The same is true for computers, cell phones, and PDAs.) For example, a 40 percent charged battery stored around 77 degrees maintains 96 percent of its permanent capacity after a year, while one stored at 104 degrees holds only 85 percent capacity. If it's stored fully charged, that decreases to 65 percent. So store batteries in a cool place and at a 40 percent charge if not being used.

Charging Up

Many computer manufacturers sell machine-specific, high-capacity batteries, which often double available computing time and usually the price too. But universal products, which may offer longer life or a more convenient package, also are available.

Electrovaya PowerPads use lithium polymer technology to deliver from two to six times more power - 12 to 16 hours in some cases - and range in price from $249 to $449. The letter-size, less than 1-inch-thick pads sit underneath notebooks and laptops and connect through the AC power port. Contact www.electrovaya.com.

The N-Charge Power System offers up to 10 hours of continuous notebook use. Similar to the size and weight of a notebook computer, this recharger also sits under the laptop computer and connects through the AC port. It can charge two devices simultaneously without an adapter and works with all popular models. A smaller model offers half the weight and power; the systems run $300 and $200. Contact www.valence.com.

Handheld Computing magazine named iGo Juice 2003's best choice for portable power. This combination AC/auto/in-flight power adapter is compatible with most major computer brands. With the additional peripheral powering system you can charge a cell phone or PDA while charging (or using) your laptop. The adapter costs around $120; the PPS is another $20. Contact www.igo.com.

Those looking for a lighter load to carry should check out the Targus Universal Auto/Air Notebook Power Adapter. At six ounces, it's about two ounces lighter than iGo Juice, but it doesn't have the AC adaptability. You also can charge mobile phones, PDAs, and other peripherals after buying separate power tips. The adapter is $100; the power tips run about $20 each. Contact www.targus.com.

Go even lighter and keep the three-in-one idea with Kensington's Universal AC/Car/Air Adapter, which also uses the iGo PPS system for powering peripherals. The Kensington adapter is about $150 but several Web outlets sell it for less. Contact www.kensington.com.

Peripheral Power

To charge your PDA and synchronize with your laptop, use the appropriate Zip-Linq sync-and-charge spring-loaded cable. Plug one end into your notebook's USB port and the other end into your PDA. The retractable cable expands to about 30 inches and supports most major PDA brands. A similar device is available for charging cell phones; both types cost around $15. Contact www.ziplinq.com.

Desperate for a few extra minutes on your cell phone to cinch a deal or make a contact? Targus' emergency USB chargers let you charge your 9-volt cell phone battery through your computer for about 30 more minutes of talk time. It works with certain Nokia and Motorola models and costs $20. Contact www.targus.com.

Cellboost instant battery chargers serve a wider selection of cell phones. Lasting three years, Cellboost plugs into your phone for 60 minutes of talk time and 60 hours of standby time and costs about $6. Contact www.cellboost.com.

Instant Power zinc-air batteries bring dead cell phone and PDA batteries back to life, and you can use the device while it charges. The charger has a three-year shelf life and lasts for three months if you keep it in the reclosable pouch. The power cartridge is universal but you need a special smart cord for your particular device; for $14.95 you can buy two power cartridges and a smart cord. Contact www.instant-power.com.

Products included in Technology Bueyrs Guide articles are for informational purposes only. Inclusion of a product does not constitute review or recommendation.