Electric Car From Mitsubishi

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.

Source:Motor trader