A Samsung subsidiary has developed a fuel cell prototype capable of powering portable multimedia players for four hours. However, the technology, which uses methanol cartridges, will not be commercially available before 2007 or 2008. Samsung SDI expects, by then, to offer a miniaturized version of the solution providing up to 10 hours of continuous operation on a single charge. The company has invested close to USD 4 million in fuel cell development since 2004.