With the new fourth-generation smart electric drive, Daimler’s smart brand is applying electrification across all models in the range. smart will be the only car manufacturer worldwide currently to offer its full model range with both combustion engines and all-electric drive. The market launch will start in the spring of 2017. In Germany prices for the smart fortwo electric drive start at €21,940 (US$23,077)—recommended retail price including 19% VAT.
A 60 kW (81 hp), electric motor runs at the rear of the smart electric drive and transmits 160 N·m of torque via a single fixed gear ratio to the wheels. Powered by a 17.6 kWh Li-ion battery pack, the electric drive has a range (NEDC) of approximately 160 km (99 miles); maximum speed is electronically limited to 130 km/h (81 mph) to maximize the range. Combined cycle power consumption is 12.9 kWh/100 km.
The electric motor is a separately excited three-phase synchronous motor. This configuration incorporates an excitation winding on the rotor that is magnetized when current flows. The flow of energy from the high-voltage battery to the electric motor is controlled by the power electronics that are compactly interlocked with the drive unit. The drive is produced in Renault’s plant in Clèon, Northern France.
The smart is equipped with a lithium-ion battery from the Daimler subsidiary Deutsche ACCUMOTIVE. The company based in Kamenz, Saxony, has been building the electric heart of the smart electric drive since 2012. The battery has capacity of 17.6 kWh and is housed in the vehicle underbody between the two axles. The battery comprises 96 flat cells and the cell chemistry has been improved compared with the predecessor battery.
The new battery warranty guarantees that the maximum energy content is not less than the specified battery capacity over eight years and/or to a mileage of 100,000 kilometers (62,137 miles).
With the onboard charger, in the USA and the UK the charging time is 2.5 hours—half as long as for the predecessor. From the autumn of 2017 a 22 kW fast charger will be available as an option in Europe. This enables the smart electric drive to be charged in less than 45 minutes (0-80%) when local conditions allow three-phase charging.As well as the basic drive program the smart electric drive driver can select the ECO mode. This is designed for a particularly efficient driving style. In addition, the maximum speed is limited, the accelerator pedal curve adjusted and the maximum recuperation level is pre-selected. Furthermore, the air conditioning control adjusts the outlet air temperature from the air vents to reduce the energy consumption.
The driver can deactivate the ECO program with the kickdown function if necessary, for example for overtaking. Pushing the accelerator pedal right down activates a temporary boost. This enables maximum acceleration with defined maximum battery power if the current charge level and the temperature of the battery allow this function.
In overrun mode or when braking the vehicle’s kinetic energy is converted into electrical energy. The smart electric drive models have anticipatory radar-based recuperation as a standard feature that is active in the basic drive program. The traffic situation is monitored with a radar sensor and a recuperation level that suits the current situation is selected. The electronically controlled recuperation takes place in five levels as soon as the driver takes his or her foot off the accelerator pedal (overrun mode). If the road is clear coasting is activated. In the ECO drive program the highest recuperation level is automatically set.
The driving characteristics are agile and lively. The ultra-small turning circle also contributes to this, and at 6.95 meters for the two-seater it matches that of its sibling with conventional drive.
The “smart control” app enables simple operation of many functions of the smart electric drive. smart drivers can see the current battery state of charge and the range before they set off or activate the pre-entry climate control of the interior while the car is charging. Functions include:
Vehicle information: battery charge level, range, average fuel consumption, mileage, eco score, next service, tire pressure.
The vehicle functions departure time and pre-entry climate control: compared with the previous series, two programmable departure times mean that these functions do not always need to be re-set for frequent journeys—e.g.,the daily commute. The programmed departure time can be used both for intelligent charging and for the pre-entry climate control. If the departure time is set the previous evening, the vehicle has the requested interior temperature the next morning. If the customer wants to spontaneously set the temperature before a trip for a vehicle that is not connected to a charging station this can also be done via the “smart control” app as long as the battery charge level is at least 30%.
Charging properties: during the charging process the charge level, remaining charging time, charging capacity, range, the current state of charge (SOC) and the charging profile (expected state of charge depending on the time) can be called up. In addition, the smart electric drive enables convenient charging with automatic authentication and cashless payment in accordance with the ISO 15118-defined Plug & Charge profile. When a contract has been concluded with an energy provider the contract certificate needed can be transferred to the vehicle via a charging station. The “smart control” app assists the customer with the contract conclusion by displaying the Plug & Charge ID. The current contract status in the vehicle is always shown on the “smart control” app. Furthermore, “intelligent charging” can be activated for a charging process. With the help of information from the infrastructure or—if this is not available—a tariff table specified by the driver on the “smart control” app cost-optimized charging of the vehicle is possible. The tariff table can also be used to select solar power from the customer’s own photovoltaic system as the preferred charging option, for example.
Electric history at smart. With the start of the first electrically driven test fleet in 2007 in London, smart also took on a pioneering role in the field of electric mobility when 100 smart fortwo electric drives took to the roads of the British capital.
In 2009 smart launched the second generation of the smart fortwo electric drive, with the model introduced in 18 markets. The objective was to gather as much experience as possible about how customers use and charge electric vehicles. The huge demand exceeded all expectations. Instead of the planned 1000 vehicles more than 2000 smart fortwo electric drives were produced in Hambach.
From June 2012 the third generation of the smart fortwo electric drive also succeeded in winning wide-ranging buyers for its innovative and forward-looking drive concept. Moreover, in 2013 the smart fortwo was the first all-electric vehicle from a European importer in China. In Germany, the electric smart established itself as the market leader among battery-electric vehicles within a very short space of time with a market share of around 40% and was able to maintain this position for three years in a row.
The smart electric drive also contributed to the success of the brand as part of the car2go fleet with 1,400 cars in three cities. As car2go vehicles alone, the smart electric drive has covered more than 35 million km in everyday use since the launch.