Dude in Australia heavily modified a GT-S with a 24s2p battery to run at just over 100v, but way more power to push it faster and further.

https://www.youtube.com/watch?v=aH6BL9mg8Q0

Jeff at the Float Life shows the board can freewheel at 64mph (over 100kph!!!), and he personally rides it at about 37mph before deciding it’s a bad idea to run it any faster.

Interesting custom build.