Choosing an excellent electric motor can increase the range of an ebike. 4 methods for judging an electric vehicle motor: visual inspection, auditory evaluation, temperature evaluation, resistance measurement.
Since the motor is sealed, it may require the use of external tools to fundamentally judge its quality. For example, a 4-meter tool available on the market can be used (typically sold for around 50 yuan). Apart from professional tools, readers can also assess the motor based on its appearance, materials, and overall performance.
Method 1: Visual inspection - examine the shell. A good motor typically has a bright electroplated shell, while a refurbished one may have a gray color. Look for the motor trademark, usually found on larger brands that prioritize brand quality. Additionally, check if the motor has 3C certification, which ensures compliance with industry standards and provides added security.
Method 2: Auditory assessment - listen to the power. During a test run, check if the motor provides sufficient power when starting with a load. Insufficient power may indicate compromises in the motor coil.
Method 3: Temperature evaluation - feel the temperature. After the motor stops, use your hand to assess its temperature. A lower temperature suggests better heat dissipation and motor performance.
Method 4: Resistance measurement - determine the quality of the motor. Use a 500V meter to measure the insulation value between the motor's wiring and the motor shell. A value above 0.5M ohms indicates no short circuit to the ground. For AC single-phase motors, measure the resistance of the motor case group and casing, which should not be less than 0.5 ohms. Use a multimeter to measure the inter-chip voltage between the commutators for DC motors. If the voltage pattern is consistent, it signifies normal winding.
These are some commonly used methods to assess the quality of electric vehicle motors. For regular consumers, the fourth method may be more complex, while the first three methods are more practical.