(1) 150W-180W motor 12AH battery was generally used during the development of electric vehicles before. The service life can reach 2-3 years, and now it has been improved in stages. The customer proposed that the slow speed motor should be changed to 350W-500W, and the battery was changed to 17AH-20AH. The output power of the motor is large, but the life of the battery is only reduced. It proves that the speed is not perfect.