Discharge port (DSC)
The discharge port is the main BMS port connected to the load. The DSC port is managed by the state machine and includes precharge logic to safely bring up the output voltage before fully closing the main switch.
All mentioned variables are located in folder /driver/dsc/.
Readings
| State | Unit | Description |
|---|---|---|
idscf | A | Filtered current through DSC port |
udscf | V | Filtered voltage at the DSC port |
Protection parameters
The following parameters are located in folder /driver/.
| Parameter | Unit | Description |
|---|---|---|
ishrt | A | Main short circuit current threshold |
iprch | A | Precharge current limit |
DSC port current limiter
The DSC port has its own current limiter that limits the maximum current through the discharge port independently of the pack current limiter.
Limiter parameters are located in folder /driver/dsc/limiter/.
| Parameter | Unit | Description |
|---|---|---|
idscPos | A | DSC port maximum output current |
idscPosDec | delta A | DSC port output current limit slope (0 to disable) |
idscNegDec | delta A | DSC port input current limit slope (0 to disable) |
idscNeg | A | DSC port maximum input current |
Precharging
When the DSC port is enabled, the BMS first enters the PRECHARGING state. During precharge, a current-limited path slowly charges the output capacitors of the connected load. Once the DSC port voltage reaches a sufficient level relative to the battery voltage, the main switch is fully closed and the BMS transitions to the IDLE state.
The precharge progress can be monitored by reading the DSC port voltage relative to the battery voltage.