SLAAEF5 March   2024 MSPM0G1505 , MSPM0G1505 , MSPM0G1506 , MSPM0G1506 , MSPM0G1507 , MSPM0G1507 , MSPM0L1303 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306 , MSPM0L1306-Q1 , 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 Equations
      1. 2.2.1 NomAbsSoc Calculation
        1. 2.2.1.1 Coulometer With OCV Calibration
        2. 2.2.1.2 Battery Model Filter
      2. 2.2.2 CusRltSoc Calculation
      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 Step1: Hardware Preparation
    2. 4.2 Step2: Get Battery Model
      1. 4.2.1 Battery Test Pattern
      2. 4.2.2 Battery Model Generation
    3. 4.3 Step3: Input Customized Configuration
    4. 4.4 Step4: Evaluation
      1. 4.4.1 Detection Data Input Mode
      2. 4.4.2 Communication Data Input Mode
  8. 5MSPM0 Gauge Solutions
    1. 5.1 MSPM0L1306 + 1 LiCO2 Battery
      1. 5.1.1 Hardware Setup Introduction
      2. 5.1.2 Software and Evaluation Introduction
      3. 5.1.3 Battery Testcases
        1. 5.1.3.1 Performance Test
        2. 5.1.3.2 Current Consumption Test
    2. 5.2 MSPM0G3507 + BQ76952 + 4 LiFePO4 Batteries
      1. 5.2.1 Hardware Setup Introduction
      2. 5.2.2 Software and Evaluation Introduction
      3. 5.2.3 Battery Testcases
        1. 5.2.3.1 Performance Test1 (Pulse Discharge)
        2. 5.2.3.2 Performance Test2 (Load Change)
  9. 6References

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 )
GUID-135BBF26-856A-4043-929C-20F15F2188EA-low.png Figure 2-3 SOC-OCV Table

Equation 2 is used to runtime output NomAbsSoc and Figure 2-1 is used to periodically calibrate NomAbsSoc. After two more calibrations, you can get the delta capacity and delta NomAbsSoc. Then, you can calculate the NomFullCap, as shown in Equation 4. Actually, after knowing NomFullCap, Equation 2 can work with acceptable accuracy.

GUID-3C094891-C2E3-4923-9C9F-636BA03C0C9A-low.png 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, its NomFullCap will slightly decrease due to the battery getting old. In order to track the capacity decline isssue, NomFullCap should be periodically calibrated. Equation 5 is used to represent the capacity decline, named with State-of-Health (SOH). However, in real applications, as the obtained NomFullCap has erorr, the first 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 ] )