4.1.1.1. SOC: Coulomb Counting

4.1.1.1.1. Module Files

4.1.1.1.1.1. Driver

src/app/application/algorithm/state_estimation/soc/counting/soc_counting.c

4.1.1.1.1.2. Configuration

src/app/application/algorithm/state_estimation/soc/counting/soc_counting_cfg.h

4.1.1.1.1.3. Unit Test

tests/unit/app/application/algorithm/state_estimation/soc/counting/test_soc_counting.c

4.1.1.1.2. Detailed Description

By default, foxBMS 2 uses the internal integrator of the current sensor. If the current sensor integrator is not available, the integration is made directly in the foxBMS 2 software.

The check of the presence of the integrator and the software integration are made in the Function implementing Coulomb-counting.

Listing 4.1 Function implementing Coulomb-counting

void SE_CalculateStateOfCharge(DATA_BLOCK_SOC_s *pSocValues) {

4.1.1.1.3. SE_CalculateStateOfCharge

Charge and Discharge Throughput can be calculated in two ways, depending if an external analog current counting value is available or not. The algorithm is implemented as follows:

If analog current counting value is available:

Calculate the charge difference between the latest and the previous current counting value.
Check current flow direction to evaluate if charge/discharge is ongoing.
Accumulate either charge or discharge throughput in SOC database entry.
Save time step
Save current counting value

If analog current counting value is NOT available:

Manually integrate current to calculate amount of charge since last call.
Check current flow direction to evaluate if charge/discharge is ongoing.
Accumulate either charge or discharge throughput in SOC database entry.
Save time step