Battery Discharging Current Limit

Maximum battery discharging current

Since R2022b

• 

Libraries:
Simscape / Battery / BMS / Current Management

Description

The Battery Discharging Current Limit block calculates the maximum discharging current of a battery. Limiting the charging and discharging currents is an important consideration when you model battery packs.

This block supports single-precision and double-precision floating-point simulation.

Note

To enable single-precision floating-point simulation, the data type of all inputs and parameters must be single.

This diagram shows the structure of the block:

Equations

The discharging current limit is equal to the minimum of these values:

• The temperature-dependent limit for the coolest and hottest cells

• The theoretical current based on the undervoltage limit of the cell

• The terminal resistance

$$\begin{array}{l}CurrentLimit=-\min \left(i_1,i_2,i_3\right)\\ i_1=\frac{\min (CellVoltage)-UndervoltageLimit}{R_0}\\ i_2=f(min(CellTemperature))\\ i_3=g(max(CellTemperature))\end{array}$$

where

• UndervoltageLimit is the value of the Cell undervoltage limit (V) parameter.

• CellVoltage is the value of the CellVoltage input port.

• R₀ is the value of the Terminal resistance (ohm) parameter.

• CellTemperature is the value of the CellTemperature input port.

Ports

Input

CellVoltage — Cell voltages, V

scalar | vector

Cell voltage, in volt, specified as a scalar for a single cell or a vector for multiple cells.

In R2025a: If you select the Specify inputs as [Min,Max] parameter, you must specify a minimum and a maximum value for this port, for example CellVoltage=[CellVoltageMin,CellVoltageMax].

CellTemperature — Temperature of cells, K

scalar | vector

Temperature of the cells, specified as a scalar for a single cell or a vector for multiple cells. The size of this input port must be equal to the size of the CellVoltage parameter.

If you select the Specify inputs as [Min,Max] parameter, you must specify a minimum and a maximum value for this port, for example CellTemperature=[CellTemperatureMin,CellTemperatureMax]. (since R2025a)

Output

CurrentLimit — Charging current limit for battery pack

scalar

Discharging current limit for the battery pack, returned as a scalar.

Parameters

Specify inputs as [Min,Max] — Option to specify inputs as minimum and maximum values

off (default) | on

Since R2025a

Option to specify the values at the CellVoltage and CellTemperature input ports as a vector of minimum and maximum values. If you clear this parameter, you must specify individual values for the input ports. The block then calculates the minimum and maximum values internally.

Cell undervoltage limit (V) — Undervoltage limit for cell

2.5 (default) | positive scalar

Limit under which the battery cell is undercharged, in volt.

Terminal resistance (ohm) — Terminal resistance

0.0025 (default) | positive scalar

Terminal resistance, R₀, in ohm.

Vector of temperatures, T — Cell temperatures

[243.15, 258.15, 273.15, 288.15, 303.15, 318.15, 333.15] (default) | vector of scalars

Cell temperatures. The physical unit of this parameter must be the same as the physical unit of the CellTemperature input port.

Current limit for coolest cell, iCool(T), (A) — Current limit for coolest cell

[ 0, 0, 0, 0, 100, 100, 100] (default) | vector of positive scalars

Current limit for the coolest cell, in ampere. The size of this vector must be equal to the size of the Vector of temperature, T parameter.

Current limit for hottest cell, iHot(T), (A) — Current limit for hottest cell

[100, 100, 100, 100, 0, 0, 0] (default) | vector of positive scalars

Current limit for the hottest cell, in ampere. The size of this vector must be equal to the size of the Vector of temperature, T parameter.

Algorithm data type — Option to choose data type for block algorithm

Inherit: auto (default) | double | single | <data type expression>

Since R2025a

Option to choose the data type for the block algorithm, specified as one of these values:

• Inherit: auto — You can simulate the block in both single and double precision. You must explicitly provide the inputs and parameters as either single or double.

• double — The block algorithm casts all inputs and parameters to double data type.

• single — The block algorithm casts all inputs and parameters to single data type.

• <data type expression> — The block algorithm casts all inputs and parameters to the data type object you specify.

Click the Show data type assistant button to display the Data Type Assistant, which helps you set the data type attributes. For more information, see Specify Data Types Using Data Type Assistant and Control Data Types of Signals.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2022b

R2025a: Switch between single-precision and double-precision floating-point simulation using Algorithm data type parameter

You can now easily switch between single-precision and double-precision floating-point simulation of the block algorithm by using the Algorithm data type parameter.

R2025a: Specify minimum and maximum values for input ports

You can specify the minimum and maximum values for the CellVoltage and CellTemperature input ports. To specify these inputs as minimum and maximum values, select the Specify inputs as [Min,Max] parameter.