June 13th 2023 EV SIG Meeting Notes


  • Introductions by new attendees
  • What’s new in the EV world
  • Thoughts on Caterham’s plans for EV
  • Seven Conversions
  • AOB



  • John (JM)
  • Mac
  • Tom
  • John
  • Adam
  • Rob
  • Paul


Intro’s By New Attendees

  • Adam
    • 20 years ago was given a driving experience day that including a seven
    • Took ten years to then buy a sigma which he then wrote off
    • Insurance then paid for a new car and he went for a Duratec
    • Track focused
    • Has a Nissan Leaf where he does VTG
    • Electricity Provider is Ovo
    • Uses car battery and solar to favourably export to grid
  • Rob
    • Bought Seven 10 years ago
    • Recently rejoined club and re-invigorated with car


  • Caterham’s Seven EV Announcement
  • JM has article in June LF about the press day in Swindon
  • JM said the neat thing about the announcement is the battery. Though not going to be cheap to mass produce
  • Discussion about how EV’s should be cheaper than ICE cars to construct and maintain
  • Discussion about heat in an EV and how batteries need to be at optimum temperature. Just a few percent inefficiencies can lead to a few kilowatts of heat being produced and needs to be managed to keep batteries cool in summer (and under high load) and warm in the winter (when car first started). John Kelly, Weber University just did a good video on the “heat pump” in a Tesla where lots of different systems are moving heat around the car:
  • Reviewed all the press photos sent by Caterham
    • Not all press pictures got released, so we went through them all
    • Batteries are novel because fluid passed between cells inside battery modules
    • 80L/min coolant flow
    • Double cooling that’s theoretically needed
    • Battery pack shape dictated by steering column
    • Youtube video explaining how power (BHP) and torque (lb-ft) cross at 5252rpm
    • https://www.youtube.com/watch?v=lt7iUBE3_AE
    • Discussed whether Caterham would use regen. And how the rate of change of torque going from motoring to generating needs to be considered.
    • View that lots of regen on track might not be desirable
    • But driving a car with no regen (i.e. no engine breaking) would also be odd
    • Long discussion about how battery cells are oriented inside the battery module and how there are Aluminium sandwich plates top, middle and bottom of the battery pack that provides cooling channels to feed coolant around the individual battery cells
  • Plan is to run the Seven EV up the hill at Goodwood. But they would need to build two cars in around 2 months, so lots of work to be done before Goodwood
  • Quick discussion about the Nyobolt fast charging concept car:
  • Caterham’s press shots can be found here (I’ll maintain this link for a few weeks):