Understanding road gradient or slope and how it relates to electric scooter selection
One mortal enemy of electric scooters are road gradient or slope as it greatly affects its range and speed. Note that the published maximum range of electric scooters are typically an ideal scenario where everything is easy and the road is levelled. However, recreating that exact same scenario in the real world especially for people who use electric scooters as a means to travel, rather than leisurely rides, is sometimes impossible.
Most electric scooter specification provides the maximum slope in terms of percentages. For example, The Xiaomi Essential is graded at 10% slope which is a bit over 5 degrees based on Figure 1 below while Segway E25, Mearth S, or Mearth X Pro is graded at 15% or about 8-9 degrees. While the Xiaomi Pro 2, Mercane Wide Wheel PRO (500W Single motor), and Segway MAX (2nd Gen) are capable of scaling a 20% slope of a bit over 10 degree slope. And there are some powerful scooters such as Mearth GTS, Machine FOX 1200, Machine FOX 2400, and Mercane MX60 which can scale 30% to 40% slope or 15-20 degrees.
Now you're probably thinking for the smaller motor scooters, "a 5 or 10 degree slope isn't that much and some ramps are typically sloped like that" and as a sidenote, driveways for example have a maximum of 1:12 or about 8.33% gradient just to put things into perspective. Well, nothing is really stopping your scooter from travelling to more than its maximum gradeability but if you do, expect a drop in range and speed and expect that you have to give your scooter a push to avoid over-working the motor.
Fig 1: Road gradient in degrees and percentage (Source: http://www.1728.org/gradient.htm)
How well your scooter will travel on a slope is usually determined by several factors: motor power, your weight, tyre size, and remaining battery. Generally, the larger the motor, the lighter you are, the bigger the tyres and the fuller the battery, the easier your electric scooter can travel on a hilly terrain.
Therefore, although range and speed are important in selecting an electric scooter, do not forget the terrain you will typically travel in and take the gradient or slope into consideration. Your scooter motor will thank you for it.