E-Mobility Engineering | November/December 2023 15 Dr Tilo Schweers | In conversation To create momentum for a massproduced battery EV, Dr Schweers and his colleagues gained Mercedes’ approval to build and supply 100 cars to test with customers in London, where a congestion charge had just been enforced. “That test allowed us to build these cars from converted smart Fortwos [which were originally powered by inline three-cylinder engines], then called the smart Fortwo electric drive, and the automotive world woke up. BMW started working on the Mini Electric, for instance, and once we were satisfied with the first 100, we set our eyes on the next 2000 cars,” he notes. The second-generation electric smart Fortwo benefited from the advent of Tesla and its Gen 2 lithium-ion battery with its 16.5 kWh of energy and 18650-format cylindrical cells, as well as a growing realisation across Mercedes/ Daimler that there might be a future in all-electric mobility, enabling them to be built as original EVs rather than converted IC-engined vehicles. Three more generations of smart EVs followed, each adding energy density, range, power and other benefits from advances across the electric powertrain, particularly in permanent magnet motors and HVAC systems. Dr Schweers comments that the latter’s HV compressors for air conditioning and PTC heaters for winter might seem like little things, but were critical for making EVs comfortable and acceptable to a wider audience. “And during the fourth generation, smart decided it would only produce battery EVs going forwards, meaning smart is now the only OEM that converted 100% from IC engines to allelectric,” Dr Schweers remarks. From Bremen to Beijing Following some other projects within Mercedes, he was asked by the German car manufacturer Borgward to join as an executive director of r&d for passenger cars. “I’d grown up 500 m from where Borgward had been founded, in Bremen, so it was a name I’d regarded well since childhood,” he says. “On top of that though, and unlike my work at Mercedes, Borgward enabled me to learn about China’s companies, Making the smart In 1996, while considering moving from technical research and academia into applied engineering in the commercial world, Dr Schweers was approached by MCC (Micro Compact Car), which had recently been founded as a joint venture between Mercedes-Benz and SMH (makers of the Swatch brand of watches) to cater for drivers who wanted small, stylish city cars manufactured and personalised similarly to Swatch watches. “Right away, I started working on packaging and concept design, but after 6 months I was put into a programme to create the company’s first hybrid powertrain, intended for the firstgeneration smart car,” he recounts. ‘smart’ was chosen as the name of the marque, a combination of the Swatch name plus Mercedes and art (Swatch Mercedes art). “We didn’t know exactly which direction to go in, but it soon became obvious that humanity could not go on forever just burning fuel and not think about the consequences. So after MCC became a 100% Mercedes-owned company, and was officially rebranded as smart GmbH, we created a parallelhybrid powertrain, which at the time was one of the most fuel-economic cars with potential for homologation,” he says. “Its fuel consumption was 2.7 litres/ 100 km by NEDC test standards, 0.2 litres/100 km less than the next-best competitor, but it didn’t make it into production for economic reasons.” One of the primary takeaways from the r&d led by Dr Schweers had been that electric motors could provide great speed, efficiency and comfort in small city cars. The other was a deep insight into battery technology. “Battery EVs were less complex than HEVs, and more affordable technologically, meaning on balance a better chance of achieving business success,” he says. “In fact, the biggest challenge wasn’t an engineering one but convincing the company to let us make one.” Dr Schweers led the development and first trials of the first-gen smart EQ Fortwo in 2007, with volume production for the second gen following in 2009
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