Electric Holden Commodore good to go

FIVE Holden Commodore sedans and two Sportwagons converted to run on electricity by Melbourne-based start-up EV Engineering are ready to hit the road in a proof-of-concept test.

Each car will cover between 30,000 and 50,000 kilometres in real-world conditions to evaluate customer reaction, and their performance and reliability, which will determine whether the conversion could translate into a viable business.

EV Engineering designed and built most of the electronic components in-house as well as developing the car’s onboard control software and battery-swap system, along with major structural parts such as redesigned sub-frames and the interchangeable battery pack.

Although the seven prototypes have been hand-built, EV Engineering developed the conversion to be suitable for mass production, using existing mountings on the donor car where possible and creating sub-assemblies that could be built off the car and quickly bolted into place in a production-line environment.

EV Engineering provided GoAuto with an unprecedented behind-the-scenes look at its workshop, componentry and battery-swap station, plus a brief demonstration drive at an event organised by the Society of Automotive Engineers Australasia (SAE-A) last night.

The Commodore’s familiar gear-shifter and ignition key are used as normal, the main difference being a silent start-up with a green dashboard light the main indicator that the car is ready to go.

Our brief ride as a passenger in the electric Commodore revealed it to be quiet and smooth, as expected.

The whir of the electric motor audible under acceleration and a lack of gear-changes were the main differences compared with how the petrol equivalent feels on the road.

Rather than the sharp step-off acceleration of production EVs like the Nissan Leaf and Mitsubishi i-MiEV, there was a steady build-up of speed.

The electric motor produces 145kW of power, 45kW less than the Commodore’s usual 3.0-litre petrol V6 that EV Engineering used as a benchmark, but its 400Nm of torque provides a 110Nm advantage.

This results in a 0-100km/h time of 8.5 seconds, two-tenths faster than the petrol version despite a 140kg weight increase.

Uprated springs and dampers from the Brazilian-market Commodore are fitted to help cope with the extra weight, but we hardly noticed and engineers say the result is a “slightly sportier” ride than the Calais sedan and Sportwagon donor cars.

Because the Commodore’s crash structures have not been altered and the weight gain is equivalent to a couple of extra passengers, the airbag sensors did not have to be recalibrated.

However, EV Engineering partner Bosch re-worked the ESC and ABS systems to cope with the electric Commodore’s altered power delivery characteristics and weight distribution.

Bosch found the safety aids had in some cases become more effective due to the increased responsiveness of the electric motor over a petrol engine.

Home-grown EV pioneer Ross Blade, who started converting Hyundai Getz hatchbacks to electricity in 2008, was scuppered late last year when ESC become mandatory on passenger cars and was forced to switch his focus to commercial vehicles.

The electric Commodore’s 30kWh battery provides an official driving range of 160km, similar to the smaller Nissan Leaf’s 24kWh battery, and engineers said that under real-world tests usage ranged between 130km and 157km.

EV Engineering chief engineer Tim Olding said running the electric Commodore costs about 2.2 cents per kilometre, compared with 12-13 cents for petrol.

Even when recharged using electricity generated from burning brown coal, he said it has a smaller carbon footprint than the petrol equivalent when driving in traffic.

While the battery swap system would take about five minutes, recharging takes about eight hours using a 16-Amp outlet.

A quick-charge port on some of the cars could theoretically provide up to 80 per cent top-up in just 45 minutes, but the system is not yet calibrated for general use.

A new instrument cluster developed by EV Engineering partner Continental displays remaining battery power and expected range information.

The tachometer is replaced by an analogue gauge representing how much energy is being used (or regenerated under deceleration) by the drive system, with a green zone to show its most economical operating range and the needle entering an orange ‘power’ section under hard acceleration.

A warning beeper warns bystanders when the silent Commodore EV is reversing.

After removing all internal combustion engine-related items from the donor car, EV Engineering added 24 new components in a neat installation with an almost factory-perfect finish.

The 430kg, 415-volt battery pack contains around $15,000 worth of lithium-ion cells arranged in a shape that fits snugly into the transmission tunnel and rear half of the engine bay.

EV Engineering imported the cells from South Korea but had to develop and fabricate the pack’s construction method and cooling system, including a method the team patented for bonding copper conductors with the aluminium battery terminals using high-explosives.

The control electronics are located in the space vacated by the fuel tank and fixed to existing mounting points on the chassis.

Electric motor and transmission components are mounted on the new rear sub-frame, which attaches to the Commodore’s standard suspension mounts.

Without the need for exhaust pipes and a tail-shaft, the underside of the electric Commodore is almost completely flat and more aerodynamic as a result.

EV Engineering maintained the Commodore’s hydraulic power steering system, replacing the engine-driven pump with an electric item shared with the British-built McLaren MP4-12C supercar.

An electric vacuum pump is also used for the brake booster and, like the power steering pump, is connected to a conventional 12-volt battery, as are all the safety systems found in the conventional car, to ensure the driver can maintain control in case power from the main battery pack fails.

The absence of a petrol engine also necessitated the switch to an electric air-conditioning compressor sourced from the North American Ford Escape Hybrid, plus a kettle-like electric water heater and pump to supply the cabin with warm air in winter, feeding water heated to 70 degrees through the Commodore’s existing heater matrix and plumbing.

EV Engineering senior electrical engineer Con Giatas admitted the solution of using a water heater was inefficient as the device consumes 4kW of power, reducing the car’s range when in use, so for the next project EV Engineering will switch to a reverse-cycle air-conditioning system, which uses a quarter of the power.

GoAuto observed a live demonstration of the automated battery swap system, developed and built by EV Engineering under consultation with EV infrastructure company Better Place, using a robotic battery carrier and lift device that communicates wirelessly with the car.

The battery is secured in the car using high-strength steel rods controlled by electronic actuators for insertion or removal during the battery-swap operation.

The team at EV Engineering, formed of experienced automotive engineers and a couple of university graduates, have clearly demonstrated Australia’s ability to successfully turn an iconic home-grown large car into an eco-friendly EV.