The electric vehicle controller is one of the core components of electric vehicles, responsible for adjusting the speed and power of the electric vehicle motor. Once the controller malfunctions, the performance of the electric vehicle will be greatly reduced. So, how to measure the quality of electric vehicle controllers? Here are several commonly used measurement methods. Firstly, a multimeter can be used to measure the power supply of the controller. Turn on the power of the electric vehicle and use a multimeter to measure the voltage of the red wire (positive pole) of the handlebar. Under normal circumstances, the voltage should be around 4.8V. If the voltage is too high or too low, or even no voltage, then the controller is likely to be damaged. Secondly, the quality of the controller can be determined by measuring its output phase sequence. The phase sequence of the electric vehicle controller is different between 120 ° and 60 °, and can be measured using professional tools such as a repair shop. If the phase sequence is incorrect, there may be a problem with the controller. Next, the quality of the power tube of the non electrified measurement controller. Set the multimeter to beep mode, touch the red probe against the thick black (negative pole) of the controller, and measure the yellow, green, and blue phase lines of the controller with the black probe. The three measured values should be basically consistent. Then touch the black probe against the controller's thick red (positive pole), and measure the three phase lines with the red probe separately. The values should also be basically consistent. If a certain value deviates significantly, it indicates that the power transistor may be damaged and the controller may have problems. In addition, controller faults can be eliminated through replacement methods. Sometimes controller malfunctions are intermittent or have abnormal starting, making it difficult to measure accurately. At this point, you can try replacing the controller with a new one and observe if the fault is resolved. If the fault disappears, then the original controller is likely to have been damaged. In addition to the above methods, the quality of the controller can also be judged by observing its workmanship, comparing temperature rise, observing its ability to control back pressure, testing its ability to control current, and evaluating its efficiency. For example, controllers with fine workmanship and solid materials are usually more reliable; Under the same conditions, the lower the temperature rise, the better the performance of the controller; The controller should have good anti voltage control capability and current control capability; The higher the efficiency of the controller, the longer the range of the electric vehicle. Through the above methods, we can accurately judge the quality of the electric vehicle controller, thereby ensuring the normal operation of the electric vehicle.