A design for protection must 1st define what needs to be protected then match the protection to suit the spec. for peak current * t, avg current.
Fuses have an I*t profile for fast, normal and slow blow, each different in the speed of protection of I> rated holding current vs t duration.
Where as cap loads and light bulbs have a very short peak current >> Iavg, motors can be much longer in duration with Ipk=800%*I_rated in many cases.
This time duration depends on the inertial mass ratio/torque ratio and can result in very long times. Peak current will drop as speed increases and is limited by the DCR [Ω] of the coil and switch, but It (Amp-sec) was common rating for fuses but more accurate is I²t used now due to time to melt fuse link with I²Rt energy (Wattsec)
What do you want to protect ?
- the transistor?, then use an active current limiter with 75mV currents sensor.
- the tracks from vaporizing?
- the battery current from a short? ... a Polyfuse can work or a fast blow 2~5x rated current depending on time of full motor acceleration.
A rule of thumb design requires a spec for t vs I and a SOA (safe operating area) spec for the fragile part needing protection.
With either missing, one can only hazard a guess.
use a Slow-blow 0.5W 1206 SMD fuse rated 20% above your motor worse case I²t value that you compute or measure.
1/2W is the power dissipated in the fuse at max rated current which blows in >=4hrs. Allow some 10%~20% degradation for aging depending on frequency of motor surges at full voltage.
e.g. if Imax=1.3 and Ipk=8*Imax=10.4A and Ipk²= 108[A²] which decays to 1.7[A²] at full load and full speed. Then determine time of acceleration which depends on friction and mass or change in kinetic energy.
In a well designed system the fuse loses about <=1% of the load for holding current. Depending on voltage yours may be worse such as 5% which affects peak torque, so an active 75mV shunt current limiter can be faster and more efficient if done correctly with complex filter.