18/04/2001 Across the entire history of electronic devices, from the first one-valve wireless to the latest gigahertz laptop, one truth has remained universally acknowledged. Batteries are a pain. They cost a fortune, never work when you need them, have to be swapped in and out and, in extremis, leak, catch fire and explode. And, when they've done ruining your pocket and your life, their dead bodies discharge toxic heavy metals into the environment. Ugh. So, any alternative to the tyranny of the cell is vastly overdue. Cellphone and portable computer manufacturers have been pushing the boundaries further than before and a new batch of battery beaters is being unveiled in Hannover at an industrial fair today. Casio has some solar cells that achieve unheard-of efficiencies, work at very low light levels and are much easier to make than before: good, solid work that means your laptop will keep going longer if you leave it in the sunlight (but not, presumably, where passing tealeaves out enjoying the good weather can take a shine to it). However, much more fun is had with the Fraunhofer Institute's fuel cells. These take liquid or gaseous fuel, such as hydrogen or hydrocarbons, and turn it directly into water, carbon dioxide and electricity; similar devices have powered spacecraft but have never been suitable for retail. New designs, such as Fraunhofer's matchbox-sized ten watt marvel, may change this -- but they still don't have the panache of one prototype that's been knocking around the industry for a while and which has starred in the Diary before. The size and shape of a cellphone battery, it's designed to run off vodka -- a fuel that's already available in handy stations across the nation.