Battery life has long been the Achilles heel of laptops, and whole-day duration a promise yet to be fulfilled, but a new start-up is taking a different approach to solving this issue by working on laptops so energy efficient they'll supposedly be able to run on a standard battery for 20 to 40 hours before needing a recharge.

That could be possible through ultra-low power screens developed by Mary Lou Jepsen, the former head of Intel’s display division and chief technology officer at OLPC. Such screens are one of the key features on the XO laptop, they cost a third that of traditional LCD screens and use about a tenth of the power. Increased battery life is just one of the advantages this technology brings, however, as they are also touted as being readable in direct sunlight and having a fully saturated HDTV-quality color mode.

The company, Pixel Qi, expects to begin shipping the screens for laptops and e-books as soon as the second half of 2009 and plans to develop entire laptop and PC designs around its new technology to create the most power efficient models possible.