SLAAEF5B March 2024 – June 2025 MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G3506 , MSPM0G3507 , MSPM0H3216 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1
As seen in Equation 4, in a real application, the calibrated NomAbsSoc is affected by the voltage detection accuracy, battery rest time and SOC-OCV table accuracy, which is especially critical on the LiFePO4 battery. The DeltaQ is influenced by the shunt resistor accuracy and ADC performance. This means the calibrated NomAbsSoc and the NomFullCap all include some errors. In the Gauge Level2, use a data fusion method, which has the same concept with the kalman filter. TI gives weight to all the error sources, including measured current, measure voltage, evaluated OCV and so forth. After that, users know the weight of the SOC generated through coulometer and the SOC generated through OCV calibration. At last, users can obtain a more accurate NomAbsSoc after combining these two SOCs together, as shown in Figure 2-5.
Figure 2-5 Data FusionFigure 2-6 shows the data fusion algorithm performance based on a LiFePO4 battery simulation model, with 3000 random DHG and CHG points, after considering the detection error. The AbsNomSoc error across the battery life is controlled within 3.5%, and the NomFullCap error is controlled within 4%. Remember that the result is only used to show the algorithm capability to detect NomAbsSoc with a limited condition and this does not make sure of the error range of the algorithm in a real application to detect CusRltSoc.
Figure 2-6 Algorithm Performance (By Simulation)