Our sister publication Autocar UK understands that Mercedes-Benz has pulled the plug on tests exploring range-extender drivetrains as a potential way to improve the utility and appeal of its electric cars.
Mercedes-Benz range extender powertrain
The technology that had been trialled uses a specially adapted combustion engine as a generator to charge the battery when it runs low. However, despite beginning an advanced engineering programme, the firm has decided to focus on simpler and more cost-effective battery-electric drivetrains, a source familiar with Mercedes’ car development activities confirmed.
“We have created [range-extender] prototypes based on existing models, both for packaging and road testing. In the end, though, we concluded that the range-extender drivetrain is a transitional technology with a relatively short-term benefit in terms of sales and comparatively high production costs,” said a high-level insider from the company.
Among the range-extender Mercedes prototypes is an EQS-based mule. It is claimed to feature a front-mounted turbocharged 1.0-litre two-cylinder engine – essentially half of the turbocharged ‘M254’ 2.0-litre four-cylinder engine used through its line-up – to act purely as a generator without direct drive to the wheels.
Power for the prototype is delivered by a rear-mounted electric motor developing 272hp and operating in combination with a floor-mounted lithium-ion battery. The electric energy for the battery, described as having a capacity of roughly half of that used by the production EQS, is provided by traditional AC and DC plug-in charging. The two-cylinder engine is used to create backup electricity in situations where plug-in charging is not available or possible.
In the Mercedes prototype, the petrol engine is combined with a fuel tank of unspecified capacity, giving it a theoretical range, Autocar UK has been told, beyond the 784km of the rear-driven EQS 450+.
Range extender technology
Attention has turned to range-extender electric vehicles following their increasing popularity in China. Aware of the lack of EV charging infrastructure in second and third-tier cities, many carmakers there have begun to offer range-extender options alongside pure-electric drivetrains in selected models.
Maruti Suzuki has also revealed plans for implementing this technology in India, introducing it on models like the Fronx, Swift and Baleno. Tap here to read more on it.
Suraj Viswanathan
Dipan Sur
Lenny D'sa
Viraaj Bhatnagar
Rivan RS 
Ameya Dandekar
