Mitsubishi i-MiEV

During the past decade, development of alternative ways to move cars accelerated and this decade is seeing production models either going on sale or in the final phase of testing. Different manufacturers have focused on different approaches although some have also chosen a range of options since no one is sure which will actually be the right one.

For Mitsubishi Motor Corporation (MMC), electric vehicles or EVs have been a strong focus since the 1970s (although it has also explored other solutions), initially in response to air pollution. In fact, in 1971, the company already made its first EVs - around 150 electrically-powered variants of its Minicab and Minicar that were supplied to government agencies and power companies.

The early Mitsubishi EVs used lead-acid batteries (the same as what you have in your car’s engine bay) which were the only high-capacity storage batteries available then. However, lead and acid are poisonous so the future of such batteries for EVs was not there and when lithium-ion battery technology became available in the 1990s, this became the choice of most EV manufacturers.

MMC has positioned EVs as the pinnacle of its environmental technology and the culmination of its almost 40 years of development is the i-MiEV (or ‘i-meef’, as it is referred to), an electric variant of the innovative Mitsubishi i car. The i-car, which was displayed at the last KL International Motorshow, has a radical design and compact size that lead many to think it was an EV but it actually has a petrol engine.

The unique construction of the i-car, which has its engine mounted towards the back of the cabin and the fuel tank under the middle, was ideal for switching to an electric powertrain. In place of the 35-litre fuel tank, a flat lithium-ion 330V battery pack with a capacity of 16 kWh is under the floor and the hardware for the permanent magnet synchronous electric motor goes under and behind the rear seat. The battery pack is a heavy item and positioning it low and in the middle also benefits vehicle dynamics.

The electric motor may be small and light and produce only 47 kW but when it comes to torque, it sure packs a punch! As the chart show, 180 Nm is available from start to what would be the equivalent of a third of the rpm range of the 660 cc turbocharged engine of the i-car. In comparison, the petrol engine’s torque curve starts much lower down and never gets anywhere near 180 Nm. But that’s a normal characteristic for a petrol engine and a small one can only deliver so much torque.

Driving range on a full charge is the big issue for EVs and one which has been of concern to consumers. If you have to keep recharging to drive long distances, then it’s not going to be much fun and furthermore, will there be recharging stations available? Extending the range has been a major challenge but as battery technology has advanced, this has slowly improved and the i-MiEV has a claimed 160 kms using the Japanese 10-15 mode (an industry standard for fuel consumption measurement) at an average speed of 22.7 km/h. That suggests the car is pretty much an urban commuter rather than for intercity travel. A top speed of 130 km/h is possible but that also means the battery ‘juice’ will drain faster and range will be reduced. There is regenerative charging which captures ‘wasted' energy during braking and coasting to recharge the battery but this is not significant.

Until recent years, EVs have required special charging stations, a fact that was very discouraging since consumer acceptance of such vehicles would be dependent on the assurance of an extensive network of stations – an infrastructure which would be costly and take a long time to establish. The i-MiEV eliminates this issue by having a plug-in recharging system where the car can be hooked up to a household power socket (like the one you have powering your computer) and fully charged within 7 to 14 hours, depending on whether it’s a 200V or 100V supply. There’s also the option of a quick-charging system (which requires a 3-phase 50 kW/200V supply) that will have the battery pack 80% charged within 30 minutes.

BRIEF DRIVING IMPRESSIONS
As Mitsubishi Motors Malaysia (MMM) had brought in an i-MiEV to display at the International Petroleum Technology Conference in Kuala Lumpur, the company gave the motoring media a chance to also try the car. Given that the range was limited on one charge, the route was short and confined to the area around the Saujana Golf and Country Club near the old Subang Airport in Selangor.

Driving EVs is not new to me as I have been in a few over the past ten years. I recall the very first experience in a Toyota RAV4 EV (yes, Toyota did make such a variant) in 1997 where I turned the starter switch a few times because all my driving life, I had been conditioned that turning the key was accompanied by some sound and a bit of vibration as the engine fired up. The engineer had to stop me and said, ‘No need – already on’. Then it dawned on me that with an electric motor, nothing happens till you start using it and turning the switch only allows it to start operating.

Plug-in capability allows i-MiEV to recharge using household electrical outlets

Inside the lithium-ion battery pack which is positioned under the middle of the car

I always remembered that whenever I drove an EV and it was the same with the i-MiEV except the MMC engineers must have found that virtually all drivers do need some sort of confirmation that all systems as ‘GO’ so when the switch is turned, a ‘READY’ light comes on in the instrument panel along with a soft chime!

As expected, the car surged forward like a Tamiya R/C model with so much torque coming right at the start and the weight only 1,080 kgs. There was no wheelspin, however, because the electric motor is at the back and the drive wheels are also at the back but as mentioned earlier, the battery pack in the middle helps to balance the weight distribution. Having driven the i-car last year, I felt the i-MiEV had a better ride although both cars still didn’t take bumps too well, probably because the wheels are small.

The interior is spacious for a minicar and the dashboard is laid out sensibly. It's amazing that MMC chose to give the i-MiEV quite a number of exclusive parts which only makes production cost higher when this is a low volume model (2,000 units annually at the start). But then again, it may be that the designers felt it's necessary to give the car a more high-tech image to emphasise its uniqueness.

There was no chance to check out the performance but it certainly zipped around briskly. However, hard driving will certainly drain the battery faster so an owner would have to be conscious of the fact all the time and refrain from enjoying the exhilaration of acceleration too often.

An EV makes almost no sound as it moves, which is great for the environment and great for the occupants but I wonder if it might become dangerous for pedestrians. Today, we can hear a car coming up behind and move out of the way but you might not hear an EV (especially older folks whose hearing might be poorer). So it might be pertinent for carmakers to look into this matter and perhaps have some sort of scanner like a parking sensor which will be able to identify humans and sound the horn automatically if the driver does not do so.

The i-MiEV is now going through real-world testing as MMC has supplied it to various Japanese companies to use daily. It will then be offered for sale to the public sometime in 2009 only in Japan. From next year, roadtests will also commence in selected markets with a view towards introducing the car there as well.

The projected price in Japan is around 3 million yen (about RM114,000 at today’s rates) - double that of the i-car - and that price is with a government subsidy (already confirmed). The cost of R&D has been high to make the i-MiEV a reality for the public to buy but if MMC is to include the R&D cost, the even higher price would be totally unacceptable.

It is for this reason that carmakers keep emphasizing that while they are prepared to undertake the huge investments – and risks – of developing advanced new technologies for more environment-friendly vehicles, when the vehicles are ready to be sold, governments must also share in the cost by providing subsidies to keep prices down to acceptable levels. This is crucial because the carmakers need to get up to volumes that give real economies of scale and can start to push costs down. Many governments don’t seem to see that the carmakers have done their share of ‘corporate social responsibility’ for the betterment of the country’s environment and they need the subsidy to help them make it worthwhile.