Motor: It is related to the speed of electric vehicles. Power = current * voltage, the greater the current, the electric scooter run faster, large power more expensive, but the "new national standard" requirement 2019 Nian 4 Yue 15 later, the new factory bike, speed limit 25km / h inside, So there is no need to buy too much power. Battery: The capacity of the battery is related to the endurance of electric vehicles. The life of the battery determines the later riding cost of the electric vehicle. Therefore, try to choose a large-capacity battery, and a brand with a good reputation. If the battery gap is 12v , there will be a price difference of about one or two hundred. Charger: Try to choose the kind of smart charger that can take into account both normal charging and emergency fast charging, with overcharge protection, which can automatically stop charging when fully charged, reducing charging trouble. Now most of them are smart chargers. Controller: Control the start, run, advance and retreat, speed, and stop of the electric vehicle motor.