I suggest you do more than 'hope.'
The solder jumpers on the keylock were to double the
current capacity, each connection carried half the current.
A 48V battery probably draws 10 or 12 Amperes.
That means your keylock should reasonably be able
to carry 15A continuous. (20 would be better.)
I can't imagine much less fun than pushing your bike
home when the key burns out, except possibly
having the keylock catch fire and burning your battery,
bike, and bottom.