Settings

Protections

The BMS Mini device continuously monitors the state of the cells, the external environment and, when detecting abnormalities, protects the battery and system components from damage.

Overcurrent

The BMS Mini device performs the overcurrent protection depending on current sensor values.

To change the overcurrent protection of the battery, select the "Protections → Overcurrent" section:

In this section:

• Enable – a flag to enable the protection;
• Maximum charging current, А;
• Tolerant charging current, А;
• Maximum discharging current, А;
• Tolerant discharging current, А;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of operation of the overcurrent protection, the "Overcurrent" error is generated.

Error generation conditions:

• the current is positive (charging), and its modulo value is greater than the “Maximum charging current” value for the “Delay before setting the error” time;
• the current is negative (discharging), and its modulo value is greater than the “Maximum discharging current” value for the “Delay before setting the error” time.

Conditions for removing the error:

• the current is positive (charging) or zero, and its modulo value is less than the “Tolerant charging current” value for the “Delay before clearing the error” time;
• the current is negative (discharging), and its modulo value is less than the “Tolerant discharging current” value for the “Delay before clearing the error” time.

Charge current limit

The BMS Mini device can check if the charging current exceeds the estimated limit based on the Charge map. If current exceeds the calculated limit more than configured difference, "Current limit" error is generated.

Current difference is separated to two regions by the threshold value. Maximum current in Region 1 is calculated by the absolute difference, in Region 2 – by the relative difference. 

To change the overcurrent protection of the battery, select the "Protections → Charge current limit" section:

In this section:

• Enable – a flag to enable the protection;
• Threshold to switch from Region 1 to Region 2 – a current value at which current excess calculation will be switched from absolute to relative difference, A;
• Region 1: Current difference – a value of maximum absolute current difference, A;
• Region 2: Current difference – a value of maximum relative current excess, A;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

Discharge current limit

The BMS Mini device can check if the discharging current exceeds the estimated limit based on the Discharge map. If current exceeds the calculated limit more than configured difference, "Current limit" error is generated.

Current difference is separated to two regions by the threshold value. Maximum current in Region 1 is calculated by the absolute difference, in Region 2 – by the relative difference. 

To change the overcurrent protection of the battery, select the "Protections → Discharge current limit" section:

In this section:

• Enable – a flag to enable the protection;
• Threshold to switch from Region 1 to Region 2 – a current value at which current excess calculation will be switched from absolute to relative difference, A;
• Region 1: Current difference – a value of maximum absolute current difference, A;
• Region 2: Current difference – a value of maximum relative current excess, A;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

Undervoltage

The BMS Mini device implements battery protection from too low voltage on the cells.

To change the battery protection parameters from low voltage on the cells, select the "Protections → Undervoltage" section:

In this section:

• Enable – a flag to enable the protection;
• Minimum cell voltage, V;
• Tolerant cell voltage, V;
• Check the open circuit voltage instead of the actual voltage – a flag to use the U_ocv (corrected due to current and cell resistance) cell voltage instead of measured value;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of battery protection from low voltage, the "Undervoltage" error is generated.

Error generation conditions:

• the minimum voltage among all cells of the battery is less than the “Minimum cell voltage” value for the “Delay before setting the error” time.

Conditions for removing the error:

• the minimum voltage among all cells of the battery is greater than the “Tolerant cell voltage” value for the “Delay before clearing the error” time.

Overvoltage

The BMS Mini device implements battery protection from too high voltage on the cells.

To change the battery protection parameters from high voltage on the cells, select the "Protections → Overvoltage" section:

In this section:

• Enable – a flag to enable the protection;
• Maximum cell voltage, V;
• Tolerant cell voltage, V;
• Check the open circuit voltage instead of the actual voltage – a flag to use the U_ocv (corrected due to current and cell resistance) cell voltage instead of measured value;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the battery protection from high voltage, the "Overvoltage" error is generated.

Error generation conditions:

• the maximum voltage among all cells of the battery is greater than the “Maximum cell voltage” value for the “Delay before setting the error” time.

Conditions for removing the error:

• the maximum voltage among all cells of the battery is less than the “Tolerant cell voltage” value for the “Delay before clearing the error” time.

Low temperature

The BMS Mini device implements battery protection from too low temperature.

To change the battery protection parameters from low temperature, select the "Protections → Low temperature" section:

In this section:

• Enable – a flag to enable the protection;
• Minimum charge temperature, °C;
• Tolerant charge temperature, °C;
• Minimum discharge temperature, °C;
• Tolerant discharge temperature, °C;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the battery protection from low temperature, the "Low temperature (CH)" and/or “Low temperature (DCH)” error are generated.

Error generation conditions:

• the minimum temperature among all cells of the battery is less than the “Minimum charging (discharging) temperature” value for the “Delay before setting the error” time.

Conditions for removing the error:

• the minimum temperature among all cells of the battery is greater than the “Tolerant charging (discharging) temperature” value for the “Delay before clearing the error” time.

High temperature

The BMS Mini device implements battery protection from too high temperature.

To change the battery protection parameters from high temperature, select the "Protections → High temperature" section:

In this section:

• Enable – a flag to enable the protection;
• Maximum charge temperature, °C;
• Tolerant charge temperature, °C;
• Maximum discharge temperature, °C;
• Tolerant discharge temperature, °C;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the battery protection from high temperature, the "High temperature (CH)" or “High temperature (DCH)” error is generated.

Error generation conditions:

• the maximum temperature among all cells of the battery is greater than the “Maximum charging (discharging) temperature” value for the “Delay before setting the error” time.

Conditions for removing the error:

• the maximum temperature among all cells of the battery is less than the “Tolerant charging (discharging) temperature” value for the “Delay before clearing the error” time.

Battery cover

To change the protection parameters from opening the battery cover, select the "Protections → Battery cover" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the protection against opening the battery cover, the “Battery cover error” is generated.

Error generation conditions:

• there is a signal from the battery cover during the “Delay before setting the error” time.

Conditions for removing the error:

• no signal from the battery cover during the “Delay before clearing the error” time.

Cell monitor offline

The BMS Mini device checks if there is connection with cell monitor and set an error if not.

To change the cell monitor offline protection parameters, select the "Protections → Cell monitor offline" section:

In this section:

• Enable – a flag to enable the protection;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the protection from the cell monitor offline, the "Cell monitor offline error" is generated.

Error generation conditions:

• there is not connection with the cell monitor.

Conditions for removing the error:

• connection with the cell monitor is established.

Cell count

To change the protection parameters from the mismatch of the number of cells to the set value, select the "Protections → Cell count" section:

In this section:

• Enable – a flag to enable the protection;
• Number of cells – a number of cells connected to the BMS;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

As a result of the operation of the protection from the mismatch of the number of cells, the "Cell count error" is generated.

Error generation conditions:

• the number of cells connected to the BMS is not equal to the “Number of cells” value during the “Delay before setting the error” time.

Conditions for removing the error:

• the number of cells connected to the BMS is equal to the “Number of cells” value during the “Delay before clearing the error” time.

Short circuit

The BMS Mini device implements a protection of power circuits (contactors, power wires) against overheating caused by the flow of high current for a long time.

To change the protection parameters from short circuit, select the "Protections → Short circuit" section:

In this section:

• Level 1, 2, 3 – three protection levels. The following parameters are configured at each level:
  • Enable – a flag to enable the protection;
  • Maximum current, A;
  • Delay before setting the error, second;
• Switch off the charging contactor on error – a flag to open the charging contactor when the "Short circuit" error occurs;
• Switch off the discharging contactor on error – a flag to open the discharging contactor when the "Short circuit" error occurs;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is a short circuit, the "Short circuit" error is generated.

Error generation conditions:

• at any of the three protection levels, the current modulo is greater than the “Maximum current” value during the “Delay before setting the error” time.

Conditions for removing the error:

• the current modulo is lower than the “Maximum current” values for all three protection levels during the “Delay before setting the error” time.

High contactor temperature

The BMS Mini device protects power contactors from overheating. To measure the temperature of the contactor, one of the thermistors connected to the X6 connector is used.

To change the overheating protection parameters of power contactors, select the "Protections → High contactor temperature" section:

In this section:

• Enable – a flag to enable the protection;
• Thermistor – a selection of which cell thermistor will be used as contactor temperature sensor;
• Maximum contactor temperature, °C;
• Tolerant contactor temperature, °C;
• Delay before setting the error, second;
• Switch off the charging contactor on error – a flag to open the charging contactor when the "High contactor temperature" error occurs;
• Switch off the discharging contactor on error – a flag to open the discharging contactor when the "High contactor temperature" error occurs;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is a contactor overheat, the "High contactor temperature" error is generated.

Error generation conditions:

• the contactor temperature is greater than the “Maximum temperature” value during the “Delay before setting the error” time.

Conditions for removing the error:

• the contactor temperature is lower than the “Tolerant temperature” value during the “Delay before clearing the error” time.

If there is the "High contactor temperature" error, the charging contactor opens (the “Switch off the charging contactor on error” flag is set) and the discharging contactor opens (the “Switch off the discharging contactor on error” flag is set).

Current sensor

The BMS Mini device checks the current sensor connection circuits. The circuits are checked for breakage and short-circuit to the +5 V supply line.

To change the test parameters of the current sensor connection circuits, select the "Protections → Current sensor" section:

In this section:

• Enable – a flag to enable the protection;
• Maximum voltage, V;
• Minimum voltage, V;
• Voltage hysteresis – a hysteresis value to clear the error, V;
• Delay before setting the error, second;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is an open or short circuit connection of a current sensor, the "Current sensor error" is generated.

Error generation conditions:

• the voltage in the signal line or zero level line of the current sensor is greater than the “Maximum voltage” value during the “Delay before setting the error” time;
• the voltage in the signal line or zero level line of the current sensor is less than the “Minimum voltage” value during the “Delay before setting the error” time.

Conditions for removing the error:

• the voltage in the signal line or zero level line of the current sensor is in range from (Minimum voltage + Voltage hysteresis) to (Maximum voltage - Voltage hysteresis) during the “Delay before clearing the error” time.

Charge contactor cycles

The BMS Mini device protects the charging contactor against frequent switching.

To change the protection parameters against high frequency switching of the charging contactor, select the "Protections → Charge contactor cycles" section:

In this section:

• Enable – a flag to enable the protection;
• Cycles threshold – a number of cycles in a given period, upon which the “CH contactor cycles error” is generated;
• Check time – a time in which the BMS counts switchings of the charging contactor, second;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is the high switching frequency of the charging contactor, the “CH contactor cycles error” is generated.

Error generation conditions:

• the number of switchings of the charging contactor for the “Check time” time is greater than or equal to the “Cycles threshold” value. The error is generated with the “Delay before setting the error” delay.

Conditions for removing the error:

• the “Delay before clearing the error” time has passed since the error was generated.

Discharge contactor cycles protection

The BMS Mini device protects the discharging contactor against frequent switching.

To change the protection parameters against high frequency switching of the discharging contactor, select the "Protections → Discharging contactor cycles" section:

In this section:

• Enable – a flag to enable the protection;
• Cycles threshold – a number of cycles in a given period, upon which the “DCH contactor cycles error” is generated;
• Check time – a time in which the BMS counts switchings of the charging contactor, second;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is the high switching frequency of the discharging contactor, the “DCH contactor cycles error” is generated.

Error generation conditions:

• the number of switchings of the discharging contactor for the “Check time” time is greater than or equal to the “Cycles threshold” value. The error is generated with the “Delay before setting the error” delay.

Conditions for removing the error:

• the “Delay before clearing the error” time has passed since the error was generated.

Temperature sensors

The BMS Mini device checks the temperature sensors connection circuits. The circuits are checked for breakage and short-circuit.

To change the protection parameters of the temperature sensors circuits, select the "Protections → Temperature sensors" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there are no temperature sensors connected to the BMS Mini or any temperature sensor is shorted, the "No temp. sensors" error and "Temp. sensor is shorted" error are generated respectively. These errors generated and removed with the “Delay before setting the error” and “Delay before clearing the error” delays.

WDT reset

If the BMS firmware hangs, the watchdog timer resets the device. The BMS can detect that the device was reset and generates the “WDT reset” error.

To change the parameters of the watchdog protection, select the "Protections → WDT reset" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

Conditions for removing the error:

• the “Delay before clearing the error” time has passed from the device startup.

Unallowable charging

The BMS can detect that the battery is charging through the discharging circuit and protectively open the discharging contactor to prevent unallowable battery operation.

To change the parameters of the unallowable charging protection, select the "Protections → Unallowable charging" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, second;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is charging the battery through the discharging circuit detected, the "Unallowable charging" error is generated.

Error generation conditions:

• the charging contactor is open and the battery current is not zero during the “Delay before setting the error” time.

Conditions for removing the error:

• the battery current is zero during the “Delay before clearing the error” time.

Stuck contactor

The BMS Mini device protects contactors against sticking.

To change the protection parameters against sticking, select the "Protections → Stuck contactor" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is a stuck contactor, the “Stuck contactor” error is generated. Error generation conditions:

• charging and discharging contactors are open, but the “Charging current present” or “Discharging current present” signal is set.

Contactor feedback

The BMS Mini device can receive feedback signals from contactors and detect discrepancy between the control value and the feedback signal. To enable specific contactor protection, the feedback signal must be connected to corresponding contactor feedback pin on X1 header.

To change the contactor feedback check parameters, select the "Protections → Contactor feedback" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

If there is a discrepancy at any contactor, the corresponding contactor feedback error is generated. Error generation conditions:

• a command for charging, precharge, discharging, charging/discharging or main contactor not matches its feedback value.

Insulation

The BMS Mini device can detect a signal from an external insulation monitoring device (such as Bender IR155) to monitor the insulation quality.

To change the insulation monitoring parameters, select the "Protections → Insulation" section:

In this section:

• Enable – a flag to enable the protection;
• Checking algorithm – isolation checking mode:
  • Always on – check is always performed;
  • On charging – check is performed only if “Charger connected” or “Charge request” is set;
  • Except charging - check is performed only if “Charger connected” and “Charge request” are cleared;
• Delay before setting the error, second;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

Error is set if corresponding discrete input is set up and it receives logical zero.

Critical error

To change the critical error parameters, select the "Protections → Critical error" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted.

The "Critical error" signal is generated if at least one of the critical errors (see Errors) is generated during the “Delay before setting the error” time.

The “Critical error” is cleared if there are no errors from the list above during the “Delay before clearing the error” time.

General error

To change the general error parameters, select the "Protections → Critical error" section:

In this section:

• Enable – a flag to enable the protection;
• Delay before setting the error, millisecond;
• Delay before clearing the error, second;
• Lock – a flag to block the error until the device is restarted;
• Errors 1, 2 to set the "Critical error" – bitfields to enable check of corresponding errors.

The “General error” is generated if at least one of the enabled errors is generated during the “Delay before setting the error” time.

The “General error” is cleared if there are no errors from the enabled errors during the “Delay before clearing the error” time.