I solder connectors to the spare brushes that I include in my traveling spares kit. With the connectors soldered on I don't have to worry about carrying a soldering iron to repair failed brushes.
I also check the condition of the brushes every time I have the front cover off my righteous scooter. I carry the brushes for the unfortunate riders, those who don't carry spares, that might need spares brushes. I also include a rotor, diode spares and other items for the same reason. I love airheads!
One cannot alway plan on equipment failures. Why are accidents called accidents.