text: Interesting article and I wish Formula E luck and success !
  
  BUT:
  " ...  so the only noise they produce is a persistent whine from the lithium-ion battery packs ...." 
  News flash  .-)
  Lithium ion batteries don't "whine" - they discharge their energy quietly without the racked of exploding gasoline fumes ! What you may be hearing is elecftric motor and drive train whine, air flow, tires ....