Precision resistor is a kind of very important resistor. Its precision, stability and low temperature drift design bring this resistance a superior market competitiveness. The accuracy of precision resistance represents the accuracy of resistance value. In fact, the accuracy is affected by many factors, such as ambient temperature changes, , self-heating due to self-energizing, pressure or tension from the PCB, external moisture, even corrosive gases, or welding, pulse, overload, static electricity, radiation and so on. These factors that affect the accuracy of the resistance of the precision resistance are collectively referred to as stress. All stresses change the resistance value, thus affecting the precision of the resistance value.
As a new energy automobile power system, more and more precision resistors are being used. Many battery management systems attach great importance to the accuracy, stability and low temperature drift of the resistor. In these three parameters, more battery management system manufacturers pay much more attention to the stability of precision resistors. If the stability of precision resistance is insufficient, can not guarantee the long-term stable operation of new energy vehicles can not be guaranteed. If there is a problem with the precision resistor, it is easy to cause a safety accident in the new energy vehicle.
Although there are many different techniques and materials in the application of precision resistance in battery management system, almost all precision resistors need to be adjusted in order to achieve high stability and high precision. The resistance value of the precision resistance will be affected by various factors, and it is meaningless to leave the high precision of the stability. For example, the precision of the resistance factory is ±0.01%, but the resistance value may change more than ±500ppm or more after a few months of storage or hundreds of hours of load. Another common case is that the precision resistance is within the nominal precision range when the incoming material is checked, and after welding to the PCB in the battery management system, the precision range of the nominal resistance exceeds the nominal precision range. In addition, both electrostatic and wet conditions will lead to irreversible changes in resistance values.
An excellent battery management system is accurately measured in many details. Without exception a small precision resistor is tested. In the precise resistance selection, the accuracy of the use of measuring instruments and the correct measurement method is also very important. It is also important to control the resistance brand and channel when purchasing the resistance.
