Going electric a 'smart' move - but SA will wait

Two decades of losing money on the expensive Smart city car brand look like they might finally pay off. Like the Mercedes A and B classes, all Smarts were conceived with electric power in mind and the new one, which made its debut at the Paris Motor Show in 2016, will be the fourth generation of zero-emission Smart Fortwo.

Smart is the only car brand in the world to offer electric versions of every model it makes.

Three-phase synchronous motor

Sharing much technology with Renault's Twingo has not hurt the electric Smart's development path, not least because it gave the brand access to a five-door hatch. At the core of the three-model range (Fortwo, Fortwo cabrio and Forfour) is a three-phase synchronous motor, delivering 60kW power and 160Nm torque.

Like internal combustion engine Smarts, the motor in all three models sits over the De Dion rear axle. Unlike the internal combustion engine Smarts, there is no dual-clutch transmission alongside it. Instead, there is just a single gear and when the driver selects reverse, the Smarts simply run the electric motor backwards.

This reversible single-speed drive system is claimed to be a bonus in heavy traffic.

The motor's rotor is magnetised whenever current flows, with the energy flow from the high-voltage, lithium-ion battery governed by an electronic control unit that also controls the drive system.

All three versions share the 17.6kWh battery pack beneath the front seats (or, in the two-door versions' case, the only seats).

Battery pack

Built by Saxony's Deutsche Accumotive, Daimler's wholly-owned battery subsidiary, the pack uses 96 flat cells. Its chemistry has been improved to the point that Daimler guarantees the quoted capacity and power output rates will remain for the cars' minimum eight years or 100,000km.

Deutsche Accumotive also made the battery pack for the third-generation BEV Smart Fortwo, though this one outstrips it by offering a claimed 160km range, limiting the top speed to 130km/h.

While the coming wave of premium electric cars will use any number of custom-designed alloy cases for their battery packs, the Smarts' are in a cage of high-strength steel tubes. The cars will retain standard clever features from existing Smarts, including a 6.95m kerb-to-kerb turning circle for the 2.69m Fortwo versions.

The cars receive an upgraded on-board charger that halves the recharge time to two-and-a-half hours in the UK and the US. There will also be a 22kW fast charger in some parts of the world that allows the cars to utilise three-phase power to cram an 80% charge into the battery in just 45 minutes.

Energy conservation

Another tweak for keeping the BEV Smarts moving is an anticipatory radar-based energy recuperation system to minimise wasted braking energy by harvesting as much energy as possible.

Besides a softer throttle response and a lower top speed, the Smart's more frugal Eco mode also gives up five rates of recuperation urgency, converting kinetic energy into electrical energy.

Its radar monitors the surrounding traffic and lets the car coast if there is no traffic, then uses the electric motor as a generator to harvest energy depending on how quickly the car needs to wash off speed.

The enthusiasm with which it harvests energy depends on the battery's temperature and state of charge.

Another way it saves energy is by forcing the climate control to reach a preset temperature while the car is attached to the charging station, and that can be adjusted via a smartphone app.

It has also moved to counter concerns about pedestrian interaction with a quieter generation of urban transport by fitting the US cars with a weatherproof speaker in the grille. The speed-variable system works predominantly below 30km/h and will be optional in Europe.

Feasability

This all brings us to the issue of whether the Smart will go the electric route in SA. Sadly not. According to a spokesperson for Mercedes-Benz SA, feasibility studies have shown it is not favourable to bring the electric versions to our market. The company is apparently constantly monitoring the situation and if electric vehicles become more popular in the country the decision might be reconsidered.

BMW has its i models, Nissan has its Leaf and in 2018 we will get the Jaguar I-Pace and possibly the Tesla Model 3, but few models look as though they should be electric as much as a Smart.

Source: Business Day