On-the-go power: Mobile chargers keep your devices alive

If you depend on your smartphone or tablet to keep up with a full day's activities, one of these mobile chargers will make sure you have a recharge handy, even with no power outlets in sight.

Mobile battery chargers

It's inevitable: At some point during a busy day of business travel, your smartphone is going to run out of juice -- usually when you don't have access to a wall outlet. While some smartphone owners can drop in a spare battery, others (who use, say, Apple's iPhone or Motorola's Droid Razr) don't have that option. Their best plan is to get a mobile charger.

Mobile chargers vary greatly in capacity, size, style and price. Most can charge your phone and other small devices, and some can also handle tablets (but not laptops). Arranged from largest capacity to lowest, here's an array of chargers to get you and your phone through the day.

Iogear GearPower High Capacity Mobile Power Station

Many of us carry more than one mobile device around, and the Iogear GearPower High Capacity Mobile Power Station lets you charge a couple at the same time using its two USB power ports. It can, for example, charge a tablet and a phone, or two phones; it can also handle a digital camera and most MP3 players.

You can use either your own device's power cable or the Micro-USB cable that comes with the GearPower. The GearPower recharges via a wall socket or a computer USB port, and comes with its own carrying case.

Price: $79.95
Capacity: 6600mAh
Dimensions & weight: 4.4 x 3.5 x 0.6 in.; 12 oz.

myCharge Portable Power Bank 6000

If you're a power user -- in both senses of the word -- you might want to try out the myCharge Portable Power Bank 6000. This compact battery pack comes with three built-in connectors for Micro-USB, Mini-USB and Apple devices; it also has a standard USB port so you can plug in any USB charging cable.

According to the company, the Power Bank is capable of charging the average smartphone four times, and giving an iPad a nearly complete battery boost. Have more than one device? You can charge up to four simultaneously. 

Price: $99.99
Capacity: 6000mAh
Dimensions & weight: 4.4 x 2.9 x 1.0 in.; 6.5 oz.

Zaggsparq 2.0

Zagg's Zaggsparq 2.0 charger offers two USB ports into which you can plug the charging cables of your phone or tablet, allowing you to charge two devices simultaneously. The top port is, according to the company, optimized for smartphone charging.

Fold-away AC prongs serve to recharge the unit, while four yellow lights give you an indication of how much power is left. Zagg's website says that it can offer your smartphone four complete recharges and take an iPad from 0% to 60%.

Price: $99.99
Capacity: 6000mAh
Dimensions & weight: 3.5 x 3.5 x 1 in.; 8.6 oz.

FatCat PowerBar 4200

The FatCat PowerBar 4200 is not only useful, but stylish as well -- the slim, lightweight unit comes in silver, black, blue, orange or red. It will charge cellphones, smartphones, MP3 players and other small devices, and, according to the company, it will last for up to 500 charges.

It comes with a master cord with two female connectors and six tips (male USB, female USB, Micro-USB, Mini-USB, iPod/iPhone and DC 3.5 x 1.3); the company says it has other tips available for older devices. You also get a travel case.

Price: $69.95
Capacity: 4200mAh
Dimensions & weight: 4 x 2.4 x 0.5 in.; 4 oz.

Solio Bolt

It's bad enough when your phone runs out of power; but when your charger runs out, you've really got a problem. This is not an issue with the Solio Bolt -- a compact unit that folds out into two solar panels; you can either tie it to the back of your backpack or stick a pencil into it to prop it up and point it to the sun. (It also recharges via USB or an electric outlet.)

The Bolt comes with a standard USB port that you can use with your device's cable or the included USB/Micro-USB cable. Use the on/off button to save energy when not charging.

Price: $70
Capacity: 2000mAh
Dimensions & weight: 3.5 x 3.5 x 1 in.; 5.3 oz.

iGo Charge Anywhere

It's often not enough to charge a single phone. The iGo Charge Anywhere offers two USB ports for simultaneous charging -- so not only is it convenient away from home, but also, when plugged into the wall, it can easily charge two devices using one electric outlet. The unit comes with a free device tip so that you don't have to carry as many cables around with you. It includes fold-away AC prongs and a button that begins the charging process.

The iGo will charge phones (at 1800mAh, it should fully charge a single smartphone), Bluetooth headsets, digital cameras and other small portable devices. 

Price: $39.99
Capacity: 1800mAh
Dimensions & weight: 2.3 x 2.5 x 1.5 in.; 3.8 oz.

Tylt Energi

For something compact and practical, check out the Tylt Energi battery pack (currently available as the Sprint Travel Charger Plus; it will be sold under its own name by T-Mobile starting April 15). The Energi can power two devices at the same time via its Micro-USB charging cable (which then disappears neatly into a slot on the side of the unit) and a standard USB port.

It regains its strength via fold-away AC prongs, while an LED indicates how much power the Energi has left. According to the company, it can fully charge a smartphone or provide a third of a charge to a 7-in. tablet.

Price: $39.99
Capacity: 1800mAh
Dimensions & weight: 3.0 x 2.5 x 0.9 in.; 3.8 oz.

PowerTrekk

There are chargers that get their juice from electric outlets, solar panels or hand cranks -- and then there's the PowerTrekk, which gets its power from...water.

This fuel cell device contains two compartments: One holds the actual battery (called a PowerTrekk Pukk), and the other holds about a tablespoon of water. Insert the Pukk, fill it with water, connect your device and go. (You can also use its standard 1500mAh battery if no water is available.)

Each Pukk, which can fully charge a smartphone, must be replaced after use (a 3-pack will cost $12). The PowerTrekk will be available this May.

Price: $229.99
Capacity: 1500mAh
Dimensions & weight: 5 x 2.6 x 1.8 in.; 8.6 oz.

Third Rail Smart Battery

There are many cases available for the iPhone, some including batteries. Third Rail recognizes that even iPhone users may have other devices; its Smart Battery can be used as a standalone universal charger or paired with its Slim Case ($39.99), which charges an iPhone 4 or 4S when the battery is attached to the back of the case.

The Smart Battery has two Micro-USB ports, one for charging your devices (a cable and USB adapter are included) and one for recharging the battery itself. It can handle phones, cameras and other small devices; an LED array shows how much power is left.

Price: $59.99
Capacity: 1250mAh
Dimensions & weight: 3.3 x 1.8 x 0.3 in.; 1.4 oz.

Enercell Micro USB Portable Power Bank

If you just want something small and inexpensive for emergencies, Radio Shack's Enercell line of battery packs may be worth a look. The Enercell Micro USB Portable Power Bank, for example, is set up to power your phone for up to 100 additional minutes of talk time with its built-in Micro-USB connector.

The Enercell battery recharges via a built-in standard USB connector. It's got an on-off switch and a light that shows red when it no longer has a charge. Not high-end, by any means, but it will get you those extra minutes if you need them.

Price: $19.99 
Capacity: 800mAh 
Dimensions & weight: 3.2 x 2 x 0.5 in.; 2.5 oz.

Eton FRX3

It may look like an alien spacecraft, but the Eton FRX3 is actually a highly useful device for hikers and other travelers who may find themselves far from an electric outlet. At 600mAh, the FRX3 won't fully repower your phone, but it can give the battery a good boost via a USB port.

In addition, the glow-in-the-dark FRX3 has AM/FM/WB (weather band) radio, an alarm clock and an LED flashlight. It repowers via a solar panel or a hand crank -- or you can just plug it in when you get home. The Eton FRX3 will be available April 3rd.

Price: $60
Capacity: 600mAh
Dimensions & weight: 6.9 x 5.8 x 2.6 in.; 1 lb. 5 oz.

Aviiq Portable Charging Station

The Aviiq Portable Charging Station is not a mobile charger per se; it's a place to keep and charge all your mobile devices in one swell foop. The small black travel bag lets you neatly store and charge up to four USB devices. You plug them into a common port inside the bag; that, in turn, plugs into a single wall outlet.

The bag also includes a retractable USB cable that lets you sync any of your devices to your computer. It's a handy way to keep your portable devices topped up -- and to make sure you don't leave any in the hotel room.

Price: $79.99
Capacity: N/A
Dimensions & weight: 10 x 1.5 x 5 in.; 1 lb.