SLAAEF5B March   2024  – June 2025 MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G3506 , MSPM0G3507 , MSPM0H3216 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Algorithm Introduction
    1. 2.1 Battery Basic Knowledge Introduction
    2. 2.2 Different SOCs and Used Technologies
      1. 2.2.1 NomAbsSoc Calculation
        1. 2.2.1.1 Coulometer With OCV Calibration
        2. 2.2.1.2 Data Fusion
        3. 2.2.1.3 Battery Model Filter
      2. 2.2.2 CusRltSoc Calculation
        1. 2.2.2.1 EmptySoc and FullSoc
        2. 2.2.2.2 Core Temperature Evaluation
      3. 2.2.3 SmoothRltSoc Calculation
    3. 2.3 Algorithm Overview
      1. 2.3.1 Voltage Gauge Introduction
      2. 2.3.2 Current Gauge Introduction
      3. 2.3.3 Capacity Learn Introduction
      4. 2.3.4 Mixing Introduction
  6. 3Gauge GUI Introduction
    1. 3.1 MCU COM Tool
    2. 3.2 SM COM Tool
    3. 3.3 Data Analysis Tool
  7. 4MSPM0 Gauge Evaluation Steps
    1. 4.1 Step 1: Hardware Preparation
    2. 4.2 Step 2: Get a Battery Model
      1. 4.2.1 Battery Test Pattern
      2. 4.2.2 Battery Model Generation
    3. 4.3 Step 3: Input Customized Configuration
    4. 4.4 Step 4: Evaluation
      1. 4.4.1 Detection Data Input Mode
      2. 4.4.2 Communication Data Input Mode
    5. 4.5 Step 5: Gauge Performance Check
      1. 4.5.1 Learning Cycles
      2. 4.5.2 SOC and SOH Accuracy Evaluation
  8. 5MSPM0 Gauge Solutions
    1. 5.1 MSPM0L1306 and 1 LiCO2 Battery
      1. 5.1.1 Hardware Setup Introduction
      2. 5.1.2 Software and Evaluation Introduction
      3. 5.1.3 Battery Test Cases
        1. 5.1.3.1 Performance Test
        2. 5.1.3.2 Current Consumption Test
    2. 5.2 MSPM0G3507, BQ76952 and 4 LiFePO4 Batteries
      1. 5.2.1 Hardware Setup Introduction
      2. 5.2.2 Software and Evaluation Introduction
      3. 5.2.3 Battery Test Cases
        1. 5.2.3.1 Performance Test 1 (Pulse Discharge)
        2. 5.2.3.2 Performance Test 2 (Load Change)
    3. 5.3 MSPM0L1306 and BQ76905
  9. 6Summary
  10. 7References
  11. 8Revision History

2.2.1.1 Coulometer With OCV Calibration

The common method to update NomAbsSoc is to use coulometer, which is shown in Equation 1 and Equation 2.

Equation 1. Q u s e = I t * ∆ t
Equation 2. N o m A b s S o c = N o m F u l l C a p - Q u s e N o m F u l l C a p

As coulometer has error accumulation problems. NomAbsSoc is purely calibrated by using the OCV, which is determined after the battery is rested for enough time. An OCV to SOC search table example is shown in Figure 2-3.

Equation 3. N o m A b s S o c = f ( O C V )
SOC-OCV Table Figure 2-3 SOC-OCV Table

Equation 2 is used for run time output NomAbsSoc and Figure 2-1 is used to periodically calibrate NomAbsSoc. After two more calibrations, users can get the delta capacity and delta NomAbsSoc. Then, calculate the NomFullCap, as shown in Equation 4.

OCV Calibration and Capacity Accumulation Figure 2-4 OCV Calibration and Capacity Accumulation
Equation 4. N o m F u l l C a p = ∑ A B S ( ∆ Q ) ∑ A B S ( ∆ N o m A b s S o c )

For a real battery, the NomFullCap slightly decreases due to the battery getting old. To track the capacity decline issue, periodically calibrate the NomFullCap. Equation 5 is used to represent the capacity decline, named with State-of-Health (SOH). However, in real applications, as the obtained NomFullCap has error, use the maximum obtained NomFullCap is used as the Max NomFullCap.

Equation 5. S O H = N o m F u l l C a p [ n ] M a x ( N o m F u l l C a p [ n ] )