A small British technology company claimed last week it had made a breakthrough with a new design of fuel cell, according to a May 19 Reuters report. Cambridge-based CMR Fuel Cells said it has designed a fuel cell that is a tenth of the size of existing models. The new fuel cell is small enough to replace conventional batteries in laptop computers. The new design will run for four times longer than conventional batteries in a laptop or other devices like power tools, and is instantly rechargeable, according to Reuters. The company said the design, which would run initially on methanol, was based on new type of fuel stack that mixed air and fuel. Up to now fuel stacks have relied on complete separation of the two. Fuel cells have for years been touted as the power source of the future. But high costs and doubts about widespread availability of fuel -- usually hydrogen -- have held back the technology's transition to the mainstream despite years of research by energy firms and the automotive industry.