DC current limiting 42V

Hi. I have electric scooter xiaomi m365 which have 42V battery in it.
It does have charging port there- which is used for charging with 42v 1.7A 220v charger.#

I wish to charge my scooter outdoor from hoverboard 42V battery.
If i plug it straight up to charger port- it may go 100A and will melt my cables/burn battery PCB.

How can i limit A from my 42V hoverboard battery to charge a little bit discharged 42V scooter battery throught charging port?

There is no 42V to 42V DC to DC charger anywhere?
Siplest one will be to limit current somehow to 2A, but i can not figure out how.