First found on Instructables: http://www.instructables.com/id/Solderdoodle-Open-Source-USB-Rechargeable-Solderin/
Solderdoodle is a nifty tool with a rechargeable battery and open source hardware. It is portable, cordless and lightweight. It has heats up to 700ºF in just few seconds. It can be recharged from a USB Port. As it is portable, you can take it anywhere and charge it with one of these: Laptop, USB Battery, Wall Adapter, USB solar charger.
Though you like your premium soldering iron, Solderdoodle Pro is a great one for quick jobs. It uses a high power charge controller from Maxim and battery that is used I Tesla electric car. The soldering iron tip can be replaced using off-the-shelf components.
Interested in working with this?? Back to the project, after watching this video
Solderdoodle Pro costs:
$49 in USA.
$68 ($49 + $19 Shipping) in UK approximately.