SLAAEE3A July   2023  – June 2024 MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Gauge Hardware Introduction
  6. 3Gauge Software Introduction
    1. 3.1 Gauge Algorithm Introduction
    2. 3.2 Gauge GUI Introduction
  7. 4MSPM0 Gauge Evaluation Steps
    1. 4.1 Step1: Hardware Preparation
    2. 4.2 Step2: Get the Battery Model
    3. 4.3 Step3: Input the Customized Configuration
    4. 4.4 Step4: Evaluation
      1. 4.4.1 Detection Data Input Mode
      2. 4.4.2 Flash Data Input Mode
      3. 4.4.3 Communication Data Input Mode
  8. 5MSPM0 Gauge Solution Test Results
    1. 5.1 Performance Test
    2. 5.2 Current Consumption Test
  9. 6Revision History

3.1 Gauge Algorithm Introduction

The VGauge treats the battery as a first-order RC model then uses the RC model and the SoC-open circuit voltage (OCV) table to generate VF_SoC. As it uses a low-order circuit model to simulate the battery, the accuracy of VF_SoC is not so high. However, it can help if you know the battery SoC when you do not detect the battery current or do not know the full capacity (AbsFullCap) at the beginning. In the software code, the RC model and SoC-OCV table are saved in “circuitParamsTable”.

MSPM0L1306 Battery Model and SoC-OCV Table Figure 3-2 Battery Model and SoC-OCV Table

Figure 3-3 shows the software flow chart of VGauge function. The circuitParamsTable (Rcell lookup table and SOC-OCV lookup table ) and Qmax are per saved. When the MCU starts working the MCU treats the first AvgVcell as the OCV[K-1], then reads the SOC-OCV table to find the SoC. Rcell and Ccell are calculated and inputted in the model. With the AvgVcell input, a new OCV[K] is calculated, which is treated as a new OCV[K-1] inputted in the model in the next calculation cycle.

In a word, this model is used to evaluate the OCV based on the battery parameters and the AvgVcell input. The SoC is get by searching the SoC-OCV table.

MSPM0L1306 VGauge Software Flow Figure 3-3 VGauge Software Flow

See Current sensor-less state-of-charge estimation algorithm for lithium-ion batteries utilizing filtered terminal voltage for more details about VGauge.