Use a Portable Charger
A portable charger is a charger that you take with you. Charge it at the airport before the flight or at home before you leave. Most portable chargers provide enough power to run devices a few times. For a tablet, phone, e-book reader, or another device that charges over USB, a USB battery is all you need. Some have multiple USB ports to charge more than one device at the same time. To charge a laptop on the plane, bring a portable laptop battery charger. Not only do laptops require more power than battery chargers for phones, but you also need a way to plug the laptop into the charger. A portable laptop charger has the two-pronged or three-pronged connection needed to mimic a wall outlet.
Plug In on the Plane
In some cases, DC power adapters are used in planes, like the circular cigarette lighter power adapters found in vehicles. If that’s what’s available, you’ll need a DC-to-AC power converter. If you frequently travel with a laptop and USB devices, you might prefer a DC-to-AC converter (like this one from Foval) that includes a three-pronged port for a laptop and two USB ports for smaller devices.
Tips to Reduce Your Power Demands
If you don’t want to bring batteries with you or pay for something you’ll only use on one flight, there are some things you can do to make sure your devices remain powered for longer. One way to avoid charging your phone on a plane is to make sure it’s fully charged before you leave. Charge up in the airport before you take off or keep the phone turned off until you get on the plane to avoid using it until you need to. The same goes for other devices that need power on the plane. Another way to save phone battery, aside from keeping it turned off, is to turn off location services, dim the brightness, and turn off automatic updates. See these tips to extend iPhone battery life (or save iPad battery or Android battery life) for dozens of other tips.