How E-Scooters Work and Perform
by Author
|
|
How e-scooters work is
by adding a motor and battery to an adult kick scooter. A switch to control speed (on/off or variable) and bicycle hand brakes are mounted on the handlebar. Batteries generally fit beneath your feet. Due to wide variety of scooters available and the minimal legislation regarding them, their speeds and range vary dramatically. Speeds start below 10 mph for some inexpensive imports to over 30 mph for the others. Range varies from a few miles to 20 miles. Some have motor-protecting circuitry that requires your scooter to be moving before the assist starts. When the throttle switch is released, some scooter designs allow the motor to coast or "freewheel" like when you stop pedaling a regular bike. Simpler designs don't freewheel, and the drag of the idle motor slows the scooter. Scooter users enjoy easy acceleration, hill climbing, and cutting through headwinds. Rechargeable batteries, usually sealed lead-acid (SLA), provide power for the electric drive motors. Charging costs less than 5¢ of electricity from common 110 VAC wall outlets. Charging times vary widely due to charger output and battery capacity, but you can expect to recharge in less than 8 hours with most stock chargers. Quick chargers are available. How e-scooters perform depends on many factors. The most important factors are listed here with the (generally speaking) most important at the top: ● Terrain (number and incline of hills) ● Battery size (measured in volt-amp-hours) ● E-scooter speed (range at 10 mph is 8 times as far as at 20 mph) ● Wind conditions (going 10 mph against a 10 mph headwind feels like 20 mph to the scooter) ● Correct tire inflation (under-inflated tires slow you down) ● Weight of rider ● Motor/controller/drive system efficiency As you can see, rider weight and system efficiency rank near the bottom. The size of your battery pack and the speed you go both make a big difference in how far you go. All else being equal, range is a function of either 1) battery capacity (amp-hours X volts) or 2) speed and ease of recharging (high-power chargers provide lots of miles in less than one hour). There is a close relationship between battery capacity (A/hrs) and both weight and physical size (total volume). Generally speaking, the bigger the battery, the greater its capacity. For hill-climbing, expect about 3 feet of elevation gain for every volt-amp-hour. For example, a Currie Flyer with a 24-volt, 10 amp-hour battery pack will take you up about 720 feet (3 feet X (24 X 10)). All else being equal, speed is a function of motor (watt rating) and controller. Most scooters are capable of higher performance characteristics than the controller allows. Regenerative braking doesn't yield much "juice" back into the battery. Even hi-tech regen on electric automobiles regains less than 10% of the original charge. Therefore, given a choice of either regen or freewheeling, you will get more range with freewheeling - unless you have a very hilly route. Some scooter designs, however, effectively use regen for slowing/braking. We recommend you get a scooter with at least twice the range you usually expect to ride. |
