Singapore road test for 'electric' Prius

Modified car can be charged from socket, and run fully on electricity
Chong Zi Liang Straits Times 31 Oct 10;

The Toyota Prius may already be a petrol saver, but a team of researchers hopes to squeeze even more fuel efficiency out of the hybrid car.

GP Batteries is collaborating with the National University of Singapore (NUS) to road-test a Prius modified in Hong Kong that can be charged from an electric socket and run fully on electricity.

That would save about 3 litres of petrol or about $5 a day for a typical motorist whose daily commute to and from work makes up the bulk of his travelling. The conversion cost? About $16,300.

The team's aim is to study the plug-in hybrid electric vehicle's performance in Singapore's climate and driving conditions. GP Batteries' director of special projects Wong Kin Pun explained that batteries are sensitive to temperature and Singapore's tropical climate can affect the performance of the battery, which was originally designed in the US.

City driving, with frequent starts and stops, is also vastly different from cross-country driving. There is therefore a need to collect data from the vehicle to re-calibrate the battery.

So far, the converted Prius can travel about 30km purely on electricity. It takes four to six hours to fully charge the car and juicing up the battery will add $1.20 to your utility bill. But Mr Wong said that it is still early days yet and the modification of Priuses on Singapore roads will take time.

For one thing, the study will conclude only in March next year. Secondly, Singapore still lacks widely available charging stations to make plug-in conversion an attractive option for consumers.

But Mr Wong has his eye on companies with fleets of the hybrid car. He has contacted Prime Taxi, which owns about 40 Prius taxis, and the company has expressed interest in the technology.

The conversion process can be completed in a day by taking out the original Toyota battery and putting in a bigger, more powerful GP one - installed in the space where the spare tyre is kept. Because of the new battery's weight, the vehicle's back suspension is reinforced to support the 100kg weight gain.

But the most visible change to the user is an added panel on the dashboard which displays the different options for powering the vehicle.

Choosing between the original hybrid system and 'true electric vehicle' mode, as the modifiers put it, is as simple as pressing the right button on the panel.

It even has a third option that allows users to indicate the estimated distance of their journey. The computer system will then decide the right mix of electrical and engine power to make sure the battery lasts the whole journey.

Testing of the vehicle began in March this year, when two NUS engineering students began their internships at GP Batteries.

When the project ends next year, the engineering faculty plans to allow more students to take part in similar studies.

This will be done by studying future transport systems under the design-centric curriculum of the faculty, which aims to bring in real-world projects through partnerships with industry.

Quiet and surreal ride
Straits Times 31 Oct 10;

Silence is golden, especially when driving an electric vehicle.

Refraining from conversation or turning on the radio was the only way to appreciate how quiet the plug-in hybrid was when running on full electric mode.

I was used to the silent start of the vehicle, having driven hybrid cars occasionally, but when the silence prevailed as I continued on my spin around the National University of Singapore (NUS) campus, my driving experience took on a surreal feel.

The usual reassurance of a roaring engine was missing, yet the vehicle was moving along just fine. It reminded me of the time I drove a golf buggy, only this time, I was not negotiating grass fairways but actual tarmac roads.

Mr Wong Kin Pun, GP Batteries' director of special projects, said the internal combustion engine of the Prius will come to life when the battery charge falls below 20 per cent, or when an extra 'oomph' that electricity alone cannot provide is needed.

Indeed, as I drove up a slope on the hilly NUS grounds, I tapped the accelerator more to carry the car up faster, only for the engine to kick in and spoil my quiet time.

But Mr Wong said the Prius still packs a punch. It is capable of reaching 110kmh while running purely on electricity.

Not too bad for a golf buggy.

Chong Zi Liang