While everyone knows to carry around your iPhone or laptop charger if you're going to be away for more than half a day, sometimes you'll need even more extra power capacity while traveling or where outlets are in scarcity. External battery packs are expensive, but they're also the type of tech that pays for itself after just a few times of "I'm glad I had this" moments...One of the reasons we went with the MacBook Pro 17" is the long battery life. We can manage about 12-14 hours with one charge, but anything beyond requires plugging back in or using a battery pack. The cheapest packs will accept disposable batteries, but if you plan on being on the road without access to an outlet, then a rechargeable pack is a solid investment. Some of these packs have astonishing specs. Imaging hauling around a svelte little battery pack that will keep your MacBook going for an extra 45 hours!
1. Hyperjuice for MacBooks: What's great about these packs is they'll not only work with your MacBook, but for all of your iDevices and other USB peripherals. The 150Wh version is compact (8.9 × 4.92 × 0.83 inches) but it will keep all of your Apple devices going for up to 34 hours; charge up your laptop and your iPad, iPhone, or iPod at the same time. If you're using this solely with an iPad, you'll extend the battery life by 60 hours. You can also recharge an iPhone up to 35 times. Negatives: the weight; 2.4lbs doesn't sound like a lot, but when you're traveling it can weigh you down. The price is equally hefty; the 150Wh model sells for $350 while the 222Wh sells for $450. The 60Wh is $170 and the 100Wh is $250. Each of them will boost your devices by a different number of hours.
2. HyperJuice Micro & Mini for iPad, iPhones & iPods Designed primarily for mobile devices with smaller battery charging needs. The Mini will add 10 extra hours to your iPad's battery life, or recharge your iPhone 6 times. The battery pack is 5.2 x 3.1 x 0.55 inches and weighs 8.4 ounces. It sells for $100 for the 7200mAh or $70 for the 3600mAh.
3. Energizer XP18000: While the specs aren't as awe-inspiring as HyperJuice's offering, Energizer's XP18000 will work with all laptops and netbooks for a more modest $150. However, it will only add an extra 6 hours to laptops and 8 to netbooks. It will power your smartphones for an extra 42 hours and you'll get countless hours (600?) to power your MP3 player.
4. Battery Geeks MFP 130Wh: This pack is somewhat expensive at $400 (priced a bit more than HyperJuice's packs) but offers almost similar performance. This power pack will extend your battery life by about 3 times (8 to 15 hours). But note, this is an estimate, since the power consumption of different laptops vary.
5. Tekkeon MP3450i myPower All Plus: This pack is rated for 58Wh but cheaper at about $135. It comes with a variety of adapters so that it can charge up most devices, and can also operate as an Uninterruptable Power Supply (UPS) for battery backup.