EV-Lite was a 2 year project funded by Innovate UK, which aimed to enable mass market electric vehicle technology by reducing the mass of lithium-ion battery packs. The project was led by The Manufacturing Technology Centre and the consortium was formed of Unipoart Manufacturing, Electrovaya, CRR, Loughborough University, Cenex and Bluebird Innovation Group.
The project created a lightweight, low cost battery pack designed specifically for volume manufacturing. A whole life planning approach was adopted so that waste reduction could be achieved by designing the battery pack for disassembly and remanufacturing.
- Design of low cost, lightweight battery pack
- Weight of a 26.5 kWh sized system reduced from 295 Kg- 215 Kg with a reduction in the weight of non-cell components from 144 Kg to 72 Kg
- Cost of non-structural components reduced from £9000 to £4500
- Battery testing to ensure operation within temperature limits during typical cycles
- High volume manufacturing line designed capable of 6 battery cell assemblies per day with a 40 second TAKT time per cell
In the EV-Lite project Cenex managed the battery test and validation work package. Cenex’s work scope included developing a range of real-world battery test cycles to ensure the new project battery design was tested within a performance envelope, representative of conditions during in-service operation. Additionally Cenex used their in-house fleet performance modelling software (the Cenex Fleet Carbon Reduction Tool) to calculate the CO2 and total cost of ownership implications of using the new battery pack design in an operational fleet of EVs.
Battery test cycles
Cenex have produced a preliminary battery test procedure and six battery test cycles.
Standard test cycles for EV lithium-ion batteries and their sub systems (as defined in IEC-62660 and ISO-12405) were shown to have lower levels of current demand and current acceleration rates than EV batteries typically experience during real-world driving conditions. To enable the EV-Lite team to understand the performance of their project battery system under realistic conditions Cenex derived six drive cycles which were representative of power flows captured on EVs operating in a real-world environment.
The produced battery test cycles consist of a gentle, medium and aggressive battery cycle each for a city car EV and a large panel van EVs
The graphs below compare the EV-Lite City Car Aggressive Battery Cycle (Figure 1) and a standard test discharge profile for a battery electric vehicle (Figure 2).