5 watt to 19 watt usb converter

[Diering]

Does this exist: A 5 watt (USB) input converter to 19 watt output? I'm flying to New Zealand and I want to charge my laptop but all the seats in plebeian class have is a USB outlet.

 

[i7Baby]

So you want a converter that puts out more power than is put into it?

We all do.

 

[Solandri]

Obviously he means 5 Volt to 19 Volt, since those are the common voltages for USB and a laptop DC input. USB 2.0 actually tops out at 2.5 Watts with a standard connector.

Yes it'd be possible to rig up a transformer to step up the voltage from 5V to 19V. However, the max wattage put out won't change, and will actually go down when you factor in transformer losses. 2.5 Watts isn't enough to power a laptop, and won't extend your battery life by much (most laptops burn 8-15 Watts with light use). Even the two-plug USB power adapters would only give you 5 Watts max.

Find an airline/seat which gives you direct AC or DC power.
http/www.seatguru.com/articles/in-seat_laptop_power.php

Or if you don't mind hauling around a sealed 40 pound 12V lead-acid car battery, you could plug into that with a cigarette adapter. Good luck getting it past security though. They may have a slight problem with the sulfuric acid it contains, even if it's sealed.