ENGINEERS and scientists are claiming that a new type of battery with cells spirally wound as a Swiss roll could drastically cut the cost of hybrid cars that run on a combination of battery power and small petrol engines.
The new Rholab (short for reliable, highly optimised lead-acid battery) is the product of three years' research by a consortium working under the ForesightVehicle Programme, a UK government-funded initiative led by the Society of Motor Manufacturers & Traders and aimed at keeping the country ahead in high technology in the automotive sector.
The project has brought together experts from the European Advanced Lead-Acid Battery Consortium, battery specialists EnerSys, the Provector automotive electronics company and the UK universities of Sheffield and Warwick.
Foresight Vehicle's programme manager Patrick Selwood said the new battery could be a breakthrough for a technology that many people had written off.
"The Rholab battery could make hybrid electric cars much cheaper and reduce CO2 emissions drastically. This is another example of what bright people we have in the UK automotive research field and how dedicated scientific work can benefit us all."
The research team was given the task of finding a solution to the problem that conventional lead-acid batteries cannot cope with the high power demands of hybrid cars, and very expensive nickel metal hydride batteries have to be used instead.
The result is a lead-acid battery that is totally different from those in use but promises to significantly cut the price of hybrid cars by eliminating their need to use nickel metal hydride units.
Although it uses acid, there is no free liquid in the Rholab battery. Instead, the acid is absorbed within a glass fibre separator and the individual cells are round, not square, and spirally wound as a Swiss roll.
Each two-volt cell is fully sealed and while technically each of the Rholab battery's four 36-volt modules need only 18 cells, the researchers have cleverly built in a 19th cell that is part of the battery's secret formulation.
A spokesman explained: "The presence of this cell means that each cell in the 144-volt unit can be recharged in turn, even when the car is not being driven, without the driver even being aware it is happening.
"An electronically controlled battery management system, specially developed by automotive electronics specialists Provector, based near Cambridge, and Warwick University, constantly keeps the battery in peak condition."
The spokesman continued: "While conventional lead-acid batteries could not cope with the high power demands of hybrid cars, these specially designed cells are performing well.
"Additionally, existing nickel metal hydride batteries are very expensive and not easy to recycle, unlike their lead-acid competitors which are inexpensive and have well-established recycling infrastructure."
The Rholab battery has already been put through "gruelling" tests in a Honda Insight hybrid car and is now to undergo a full 50,000-mile (80,470km) trial at the UK motor industry's Millbrook Proving Ground.