British company launches optimised EV range-extender
04 September 2012
A technical demonstration electric vehicle using a new, production-ready range-extender has been developed and built by powertrain specialist Hyperdrive.

Hyperdrive's EV range extender unit
Based on a standard D-segment family car, the Hyperdrive CUE-V uses the company’s new single cylinder Range Extender to reduce powertrain weight by 50kg while also eliminating range anxiety. The vehicle also demonstrates Hyperdrive’s latest battery pack and battery management system (BMS).
Hyperdrive has brought together senior engineers from global vehicle manufacturers and consultancies to take a clean-sheet-of-paper approach to low-carbon vehicles. Clients already include some of the biggest names in the European automotive industry, several of whom are partnering with Hyperdrive in R&D programmes sponsored by the UK government’s Technology Strategy Board.
The new Range Extender engine is the result of a detailed review of the many technologies available for this important application. “We started with an open mind and considered many quite radical ideas – including two-strokes, rotaries and gas turbines - as well as more traditional solutions,” explains Hyperdrive director Chris Baylis. “Each one was evaluated against a pragmatic list of requirements that included cost, refinement, weight, emissions and risk. It became clear that the most attractive solution for the coming generation of range-extender EVs is to build on established expertise.”
Hyperdrive’s new Range Extender is based on a single-cylinder, water-cooled four-stroke engine that builds on proven, low-cost technologies in a design optimised for the pattern of use of this application. “The cleverness is in the combination of proven and bespoke components that allow the system to exceed the design targets with minimal cost and risk,” says Baylis. “This approach, combined with our proprietary electronic control system, allows us to fully exploit the potential of near constant-speed operation to deliver greatly improved power density without the cost and risk of significant new technologies.”

The CUE-V
In the CUE-V, the 60kg unit delivers 15kW at 5,000rpm; sufficient to allow the vehicle to cruise at 60mph without depleting the batteries. This allows a substantial reduction in the size and weight of the battery pack and of associated systems such as cooling and power electronics. Further improvements in power density are expected and the system is designed to allow an efficient design path to future generations.
The CUE-V also saves weight by using Hyperdrive’s own battery pack, which director Chris Baylis believes offers the highest energy density of any comparable system on the market today. The cable-free design integrates LiMnCo Pouch Cells with Hyperdrive’s BMS in a scalable, modular design that can also be supplied for other chemistries. Being fully weather-proof, it provides packaging flexibility that can further reduce cost and weight.
The company is exhibiting at the Low Carbon Vehicle event at Millbrook (September 5-6) stand C77.