The STW.pmb (Power Measurement Board) is an intelligent sensor for the accurate measurement of voltage and current in DC currents. The shunt (resistance)-based system is connected via CAN to the BMS with a redundant safety circuit, whereby the state of charge (SOC) of the lithium-ion battery is accurately determined.
The STW.pmb is equipped with a logical, galvanically isolated limit monitoring, a tried and tested technology for high-precision current measurement. It is available in two hardware variants with different measurement ranges for currents of +/- 1000 A or +/- 2000 A. The shunt resistance is part of the high voltage power circuit for the entire battery. It supplies accurate, high resolution data on voltage, current and temperature. A shutdown logic reliability protects the battery system in case of limit value violations.