Williams Formula E Experience Will Make Better EV Battery Possible

“Racing improves the breed,” is one of the most time-honored phrases in motorsports. Many new ideas got tried on race cars first before they were incorporated into road cars — electronic fuel injection, disc brakes, overhead camshafts, to name just a few. Formula E features battery-electric open-wheel race cars that compete on racing circuits laid out on city streets. All the cars use a 28 kWh battery supplied by Williams Advanced Engineering, a subsidiary of the Williams Formula One enterprise. The lessons learned from the first two Formula E seasons have taught Williams engineers how to make a better EV battery for road cars.

Racing flat out for 50 minutes builds up a tremendous heat, more than would ever be experienced in an ordinary electric car in daily use. Also, the combination of bumpy city streets and stiff racing suspension means the level of vibration is far higher than any passenger car would normally experience. To address those concerns, Williams Advanced Engineering has many modifications that will make a regular EV battery more robust and reliable. Paul McNamara, technical director at Williams Advanced Engineering, explains the changes:

“We have made quite a range of small changes in three areas: the first one is the cooling system – with changes to make that more robust and make it easier for us to assemble and disassemble. We’ve also done a few things to improve the performance of the thermal interface materials and the details of how the cooling tubes link up with the cells and the bus bars.

“The second area is the bus bars themselves. In the battery, we’ve got proper bus bars dealing with the quite high currents. In terms of building up the battery those bus bars all have to be interconnected. They’ve got special joints in them so that we can disarm it and bring it down to beneath 50 volts and allow us to disassemble it. Those joints have improved so they’re more resilient to vibration and the thermal displacement going into them has improved in the battery as well.

“And the final area has been in the detail design around supporting the cells, because the pack cells of the battery have to be supported and insulated from vibration and then connected into the bus bars. So, we’ve made quite a lot of detail changes to do that throughout. All of those things help us with making the batteries more reliable for the teams but they also help us in extracting more power and help us to put in more power.”

To make things more complicated, the FIA has approved a rule change for season three that allows 50% more energy to be regenerated and put back into the battery during braking. That means even more heat that the drivetrain must cope with.

“The ability to cool the battery and do all of that in a lightweight way is the key thing,” says McNamara. “If you’re trying to make an electric car, the biggest challenge you’ve got is weight. Because by the time you’ve taken away your engine and conventional gearbox, drivetrain, fuel system, fuel tank and exhaust, the weight of all that is usually lighter than what you want to put back in terms of a battery pack. The real challenge is having parity of weight while having a decent range. So making the battery lightweight is key to that, and that’s where Formula E brings learnings to us.”

The lessons learned in Formula E will result in a better, more reliable EV battery for road cars in coming years. This is one instance in which racing really is improving the breed.

Source: Electric Cars Report

Jaguar to build C-X75 hybrid supercar with Williams F1

The C-X75 concept in Paris. Click to enlarge.

Jaguar will develop the micro-turbine hybrid C-X75 concept car as a limited production supercar (maximum of 250), priced at between £700,000 - £900,000 (US$1.15 - $1.48 million) depending on local market and taxes. Jaguar expects the C-X75 to deliver CO₂ emissions of less than 99 g/km while being able to achieve in excess of 200 mph.

Jaguar says that the high-performance hybrid will stay true to the initial concept design study—albeit without the micro-turbines—that made its debut at the 2010 Paris Motor Show, while fulfilling requirements that allow it to be homologated for road use.

Jaguar says that it continues to develop the use of the micro-turbine technology that was showcased in the original concept C-X75. Jaguar’s parent company Tata has taken a stake in Bladon Jets, and will develop this technology as a medium-term aspiration that will play a part in Jaguars of the future.

Jaguar C-X75 will be developed in association with Williams F1 who will provide their engineering expertise in areas including aerodynamics, carbon composite manufacture and hybrid technologies.

Jaguar says that a direct technology transfer between elite motorsport and road-going production cars will be key to C-X75’s success. The supercar’s chassis will be made of carbon-fibre to create a lightweight, yet rigidly strong structure.

The road-going supercar will use a downsized, highly-boosted gasoline engine with one electric motor at each axle. The engine will be mounted low in the car for optimum weight distribution and to retain the concept’s silhouette, said Bob Joyce, Group Engineering Director, Jaguar Land Rover. The C-X75 will have an EV range in excess of 50 km (31 miles).

The C-X75 will feature a sub-three second 0-60 mph time and a top speed in excess of 200mph (322 km/h).

Never before has the company launched such an ambitious, world-beating vehicle program. This is the Jaguar of the future. The opportunity for innovation like this in the UK is part of the reason Tata Motors invested in Jaguar, and it's fantastic that products like the C-X75 can become reality.

—Carl-Peter Forster, CEO Tata Motors

Jaguar has appointed Paul Newsome to the position of Head of High Performance Vehicles; Newsome will lead the C-X75 joint project team from its base at Williams F1’s headquarters in Grove, UK. Newsome was at Jaguar Land Rover as Group Chief Engineer for Advanced Product Creation and Research between 2001 and 2007. During this time he led the concept creation of the T5 platform with its products Discovery 3 and Range Rover Sport and Jaguar XF and XJ.

He then joined Lotus as Director of Engineering, responsible both for the design and development of Lotus’ cars and Lotus Engineering, the global Engineering Consultancy. Paul presided over the engineering of Lotus Evora, Evora S and the new product concepts unveiled at the 2010 Paris Motorshow.

Source: Green Car Congress