Handy post from Richard Saville (aka Average Man Vs. Raspberry Pi) up on about tech.
Every model of Raspberry Pi has always required a relatively low amount of power when comparing to fully fledged desktop PCs.
Despite further hardware improvements, even the latest Raspberry Pi 3 only increased this marginally, meaning portable projects are still as easy as ever to achieve.
The Pi 3 has a recommended power supply of 5.1V at 2.5A, which will cover you for most scenarios when using the board at its full potential. The models before it demanded a slightly lower 5V at 1A, however in practice greater amperage was advisable.
For low power projects, you can reduce the amperage by quite some way before affecting performance or stability, with just a little trial and error testing for each specific project.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!