A shunt resistor and magnetic current sensor are used to measure the voltage drop flowing through. It is said the intelligence of the battery does not lie in the cell but in the complex battery system. In today's automotive applications, above two current sensing technologies is generally used.
The Shunt resistor is more accurate and less costly than the Hall Effect current-sensing solution, while the tapped holes assist in the PCB placement process, providing additional vibration immunity and the location of the fixed voltage sense pin.

 
The battery management system has three main functions:
1. Monitor battery status in real time by detecting the external characteristic parameters of the battery , such as voltage, current, temperature, etc.. The appropriate algorithm is used to estimate and monitor the internal state of the battery like capacity, SOC and more which is the basis and key for the effective operation of the battery management system.
2. Perform thermal management, battery balance management, charge and discharge management, fault alarm, etc. after correctly obtaining the status of the battery;
3. Establish a communication bus to exchange data with the display system, the vehicle controller, and the charger.

Capacity is the primary indicator of battery state-of-health (SoH) and should be part of the battery management system (BMS). Knowing SoC and SoH provides state-of-function (SoF), the ultimate confidence of readiness, but technology to provide this information in an effective way is being improved. Microhm shunt resistor will play an more important role in battery management system.