Last February we brought you news of a Massachusetts startup that is tackling one of the mobile worker's most irritating problems: limited laptop battery life.

Today that company, Boston-Power, has landed $45 million in additional venture funding to continue development and dramatically ramp up production. The infusion is being led by Oak Investment Partners and includes Venrock Associates, Granite Global Ventures and Gabriel Venture Partners.

From the press release:

The company said it would utilize the fund to scale business development, marketing, research and development, and manufacturing operations for Sonata, the company's next-generation Lithium-ion battery technology. Sonata initially targets notebook computers. Eventually, the company's products could be used to power an extensive range of end-applications - from consumer electronics devices to hybrid electric vehicles.

In addition, Boston-Power said that it has entered into a manufacturing partnership with GP Batteries.

Boston-Power has been making bold claims regarding Sonata -- that it can charge to 80% capacity in 30 minutes, or twice as fast as existing technology; and that its batteries will not fade over the course of three years, the typical lifespan of a laptop, whereas today's batteries average only 4 to 6 months before they need to be replaced.

The people with the money appear to be buying those claims.