Lenovo has expanded its ultraportable IdeaPad product line with the IdeaPad S300, S400, and S405 laptops. These affordable thin and light laptops are geared toward buyers who want more computing power than a netbook and longer battery life than a traditional laptop, without the premium price of an Ultrabook.

Lenovo Ideapad S405The S300 and S400 Series laptops are available with Intel’s 3rd generation Core i3 or i5 processors, while the IdeaPad S405 (pictured) is packed with up to AMD A8 quad core processors. Up to 500GB hard disk storage capacity (up to 1TB HDD in the S405) offers plenty of space to store media and documents, and an optional 32GB solid state drive on the S400 and S405 can help speed boot time and application responsiveness.

All of the new S Series laptops offer Microsoft Windows 7 Home Professional and will be eligible for the Microsoft Windows 8 upgrade program. Designed for Windows 8, the updated S Series’ touchpad promises a more controlled experience when scrolling and zooming, while the AccuType keyboard with individual rounded keys provides a platform for comfortable and accurate typing.

On the outside, the S Series are finished in a tactile metallic that’s available in silver grey, red, or pink. They include HDMI output and Dolby Advanced Audio v2 certified stereo speakers. The laptops measure 21.9mm thin (less than one inch) and weigh 1.8 kilograms (less than four pounds).

The S Series won’t wow you with its battery life, with only 4-5 hours between charges. However, the laptops’ energy management features and Quick Start “instant on” functionality can help increase battery efficiency to some degree.

Lenovo is including its OneKey Rescue System, which offers a quick way to back up and restore data, recover corrupted system files and run a complete virus scan.

The Lenovo IdeaPad S300, S400, and S405 are available now through Lenovo and its retail partners in the U.S. starting at US $499.

Engadget tests the IdeaPad S at the IFA expo in Berlin in this video: