30-90V to 24V 20A 480W DC-DC Buck Converter Voltage Regulator - Heavy Duty Step Down Power Supply for Golf Carts, Solar Systems, Industrial Equipment

https://www.coolgear.com/product/chargeit-100-watt-usb-type-c-charging-board Paired with a 60-to-24VDC buck step down. https://a.co/d/06WVunjs

You can install a DC-DC buck converter to keep your set up and not burn the motors. https://a.co/d/0cWcZ5dh You can also take a look at some speed controllers like the one from peanut workshop. Check if his controller can regulate the voltage.