https://www.cnet.com/roadshow/news/vw-i-d-r-pikes-peak-unique-charging-system/

The Pikes Peak International Hill Climb regulations state that, in the event of a run being suspended, electric vehicles have just 20 minutes to replenish their batteries before a second attempt. This required Volkswagen to dig deep into its battery tech, starting with the battery chemistry itself, eventually settling on a lithium-ion battery, which is split and located both next to the driver and behind him.

The I.D. R's battery is set up for maximum output, not maximum range.