If a scooter slowed down and stoped during the ride, it's most likely because it ran out of battery. Our best advice for you here is to check the battery level before you start a long ride (planning is always a good solution!).
Information about the battery level of a scooter is displayed directly in the app. You can check it easily by tapping on a scooter icon on the map.
So, if a scooter has less than 30% and you're planning a long Voiage, try looking for another one.