for 120A fuse, the blow current is 240A in a minute; continuous time under 120A is more than 4 hours.
Fuse data sheet:
% of Ampere Rating(In)
100% * In
200% * In
60 Sec Max
How longer can it last if my battery spikes over 120A?
Here is a curve to show how long time it will last in certian current.
Is 120A enough ?
1.Most of electric skateboard are not working at 120A battery current continuously, usually they are low curent, and burst current in a short time. And in the PCB it is easy to add one more fuse to extend the current to 180A.
2. This fuse current spec is for battery current, NOT for motor phase current. The current of the VESC is anchored to the running current of the motor. The supply current of the battery will not exceed the running current of the motor, and in general, the current of the battery will be much smaller than the current of the motor, especially when the motor speed is relatively low. Of course, if your motor is running at high speed and under high load, the current of the battery may be close to the current of the motor. At this time, you may consider to estimate how much fuse current you need under this situation, and the fuse can be extended to 180A at max.