EV-LITE

EV-LITE

Advancing Electric Vehicle Battery Technology

EV Lite was a two year Innovate-UK funded project starting in August 2012 which aimed to reduce the weight and cost of battery packs; a major barrier to the uptake of electric vehicles.



The Manufacturing Technology Centre led the project and worked with a consortium comprising engineers and scientists from Loughborough University, Unipart, RDVS Components, the Bluebird Innovation Group and Cenex, the Government-backed centre of excellence for low carbon and battery technology.

The project team included the Aylesbury-based Centre for Remanufacturing and Re-use which is funded by Defra.

Canadian-based battery specialist Electrovaya supported the project and provided a Maya 300 low speed electric vehicle to act as a test bed. The Maya 300 is powered by Electrovaya’s lithium-ion super polymer battery.

The project’s objectives were to redesign a battery for an electric vehicle (EV) with the following attributes:

  • Reduction in overall battery weight including structure, BMS, charging systems by 27% to 215kg, by reducing the weight of the non-cell elements of the battery by 50% from 144kg to 72Kg
  • Reduce cost of battery structure, BMS, etc. by 50% from £9000 - £4500
  • TAKT time requires automated assembly with one cell every 40 seconds, module time depending on size
  • Consideration of 2nd and 3rd life as well as recycling.

The project consortium devised a battery specification based on the Bluebird EVX sports car whilst considering a flexible design to allow reconfiguration for other vehicles. A 4kw module was targeted running a 3parrallel 12series configuration operating at a nominal 40 volts, cooling was also specified as a requirement. For the Bluebird application 8 modules would be configured in series giving a 32kWhr vehicle. Bluebird completed vehicle design to provide much of the battery structure in load bearing chassis members to reduce component weight.

A battery was designed and manufactured utilising a novel design to minimise weight whilst improving assembly. The MTC designed and manufactured high current, push-fit connections, preventing the need for screwed or welded bus bars. The MTC also worked with RDVS to re-design the Battery Management Board (BMB) allowing it to be sandwiched between the cells and bus bars, removing the need for wiring. MTC and RDVS also designed and manufactured a novel Intelligent Battery Interface System (IBIS) which dramatically saved weight and assembly time of the standard device.

The results
  • The prototype battery achieved a weight of 38Kg per 4kw module, 36Kg for a module with an IBIS, therefore a weight saving of 41% was realised on the non-cell components resulting in a 45Kg weight saving at a 26.5 kWhr sized system level
  • The cost of non-cell components was reduced from £9000 to an approximated £3396 (using volume supply chain) giving a cost saving of 63%
  • A patent application has been submitted to protect 5 key inventions in the design.

The MTC built a robotic assembly demonstration cell and completed fully automated battery builds using a dummy battery. The build was completed in 18 minutes, 6 minutes shorter than the target TAKT time.

"The EV-Lite team has made great strides in tackling the longstanding problem of battery pack weight, reducing it by more than a quarter. The consortium has also ensured that the battery pack can be manufactured in high volume on an automated facility. There are no wires or screws in the design, an innovative safety feature isolates the cells in an accident and the battery management board design is revolutionary. The project’s findings will pave the way for low cost, high volume electric battery pack manufacture in the UK."
Ken Young, Technology Director, MTC

New high spec equipment and software for research projects is continually coming into the business. This gives many training opportunities and with work being so varied I don't think I would ever have the opportunity to get bored at the MTC. The MTC is also very determined to progress engineers to chartered status. This supports my development but also awards me with an internationally recognised qualification.
Mehul Parmar
MTC Assembly Systems