Emissions-free electric vehicles could be driving on city streets far sooner than imagined as a result of a breakthrough in the kind of conventional batteries used in petrol-engined cars.
The US-based Advanced Lead Acid Battery Consortium claims that conventional low-cost battery technology is set to compete with newer more expensive nickel metal hydride and lithium batteries as the power source for new generation of electric or hybrid vehicle.
Researchers have found that fast charging a lead-acid battery improves its performance and reliability.
These souped-up versions of the traditional lead-acid cell battery can be supercharged to 50% capacity enough for a 50-mile journey in two minutes. A full charge takes 17 minutes.
But with a normal domestic electricity supply, this would take longer. To achieve the fast charging times which allow the vehicle to travel longer distances, a higher voltage supply is needed.
Not only is the battery fast-charging, it will last the life of a vehicle, overcoming two major criticisms of battery operated vehicles.
By next year ALBC members expect to produce a battery that will last 100,000 miles, or the life of the vehicle.
These developments have been made possible by the use of modern control electronics and is the result of six years’ research by ALBC, whose members funded the $35m (£$21m) programme, due to end in 1999.
The consortium represents battery manufacturers, lead producers, electricity generators and the public sector.
In the past, electric vehicle manufacturers have dismissed lead-acid batteries because of the many hours required to charge them. They need topping up with distilled water to overcome evaporation; and are dogged by what is known as premature capacity loss which sees them become progressively less able to store charge.
Researchers have perfected a technique called valve regulated design that protects the battery’s sulphuric acid supply the feed fuel it needs to produce electricity by preventing constituent hydrogen and oxygen gas from escaping to form water, which evaporates.
Costs are expected to fall as electric vehicles become more commonplace. On an electric Ford Ranger pickup costing $33,000 (£19,800) the battery accounts for less than $5,000.
British scientist Dr Patrick Moseley, director of the ALBC, said the breakthrough will benefit all lead-acid batteries used in vehicles. ‘They will become lighter and need no maintenance or topping up,’ he said.
All the car makers are working on electric models including sports versions.
So far only General Motors has a purpose-built electric vehicle, the EV-1, on sale in its showrooms.