Aussie company set to kick-start idle-stop
BY IAN PORTER | 13th Jun 2012
The company claims the addition of a supercapacitor to a normal automotive idle-stop system using a lead-acid battery will greatly extend the life of the battery and prevent the system from shutting down prematurely.
CAP-XX founder and chief executive Anthony Kongats said a supercapacitor might add $50 or $60 to the cost of a car, but could prevent several lead-acid battery failures during the life of the vehicle.
A supercapacitor is a small electric energy storage device that cannot store as much energy as a lead-acid battery of the same size, but can release its energy far quicker and can be recharged on a trickle charge from the battery.
The CAP-XX supercapacitors were developed in conjunction with four divisions of the CSIRO and are considered the most efficient on the market.
Sydney-based CAP-XX will take its products to the US in the federal government’s Team Australia Automotive trade mission later this month.
It will be looking for partners to help manufacture and sell supercapacitors to the major car-makers.
Mr Kongats said the advent of idle-stop technology has greatly increased the load on lead-acid batteries, and this is where one of the big opportunities lies for CAP-XX in the automotive market.
“Instead of doing two starts a day, one when leaving home in the morning and another when coming home at night, a battery might have to do 100 starts a day with a stop-start (idle-stop) system,” he said.
“The problem is, lots of those actions on a battery damage a battery very quickly. Batteries are chemical devices and are not good at fast charging and discharging.”This heavy workload can lead to the idle-stop system being disabled, without the driver realising.
Mr Kongats said that, as it stands, cars will meet all the emission and mileage tests when the battery is new, but as the battery starts to age the battery management system – which manages the health of the battery – will eventually turn off the idle-stop system to prevent damage to the battery.
Drivers may lose the idle-stop function in their cars in as little as three or six months, he said.
“They could restore it by getting a new battery, but the consumer is not going to be real happy replacing a lead-acid battery every six months.”However, if a supercapacitor is added to the system, it can handle all the starting needs brought on by an idle-stop system.
The lead-acid battery then only has to provide a slow charge to the supercapacitor and power the ancillary loads in the car such as the radio and the air-conditioning when the engine is off.
Tests already done in conjunction with well-known car-makers have shown that the life of a lead-acid battery in an idle-stop system can be extended by between four and 10 times through the addition of a supercapacitor.
The tests have also shown that a CAP-XX supercapacitor can start a four-cylinder engine seven times without recharging and with no lead-acid battery involved.
Mr Kongats said CAP-XX had achieved similar improvements using a supercapacitor in cold-cranking tests, with no idle-stop system installed. Cold cranking is a key element in the design of automotive electrical systems.
“The good news is that one supercapacitor module sitting alongside a lead-acid battery does both jobs simultaneously, cold-cranking and stop-start.
“It’s not like you need two supercapacitor modules to handle the cold-cranking and the stop-start.”While idle-stop systems are fitted only to a small proportion of cars at the moment, Mr Kongats said it was likely to become universal, if not compulsory, in the near future as they can offer fuel savings and reductions in emissions of more than 15 per cent.
“There has even been talk in China that they may make stop-start compulsory in new cars,” he said.
In Europe, where there is a requirement for all car-makers to achieve average fleet emissions of 120 grams of CO2 per kilometre, the manufacturers have been forced to adopt a range of technologies, including idle-stop, to reduce emissions and consumption.
Mr Kongats said there would also be applications for supercapacitors in hybrids and electric vehicles as even lithium-ion batteries have trouble accepting sudden bursts of energy like those created during regenerative braking.
Most lithium-ion battery packs require a cooling system so the batteries can stay within their normal operating temperature range during heavy use. Supercapacitors could solve that problem.
CAP-XX has already made and sold around eight million small supercapacitors for use in handheld devices such as cameras and phones, where they work in conjunction with other batteries, supplying pulses of energy for camera flashes and other sudden loads.
Japanese company Murata, the world’s leading maker of capacitors, recently started mass-producing CAP-XX supercapacitors under licence. Murata makes about two billion small capacitors a year.
A capacitor can generate a strong pulse of energy over microseconds while a supercapacitor can release its energy over periods ranging from microseconds to seconds. A supercapacitor also has thousands of times the energy density of a capacitor and can therefore store the same amount of energy in a much smaller package.
Murata is expected to start producing 100 million of the supercapacitors a year, but the demand could be 10 times that or more.
“They are targeting the mobile phone and camera industries,” said Mr Kongats. “Their interest is how to make very small supercapacitors for markets that are measured in billions of units a year.
“Murata spends around $US500 million a year on R&D (research and development) and yet they still came and licenced the technology from CAP-XX.”The automotive trade mission will start in Detroit later this month.
There will be meetings with General Motors, Ford, Toyota and BAE Systems, as well as open functions where the delegates will be able to meet other layers in the automotive industry.
The mission will then visit Tesla in California, where a similar deputation last year paid off handsomely when Futuris won a contract to supply the EV-maker with interiors. Futuris now has an operation inside Tesla’s plant.
The trade mission will be led by Australian automotive envoy Steve Bracks, the former Victorian premier who led the last automotive industry enquiry.
