Configuring a Lithium ion generic battery model
Objective : Configuring a Lithium ion generic battery model in Simulink from a battery datasheet.
For the following study data sheet of BAK H18650CH cell has been used.
Description :
The Battery block implements a generic dynamic model that represents most popular types of rechargeable batteries.
Charge and Discharge Characteristics :
A typical discharge curve consists of three sections.
The first section represents the exponential voltage drop when the battery is charged. The width of the drop depends on the battery type. The second section represents the charge that can be extracted from the battery until the voltage drops below the battery nominal voltage. Finally, the third section represents the total discharge of the battery, when the voltage drops rapidly.
Parameterization :
This figure shows detailed parameters extracted from the BAK H18650CH battery data sheet.
Following is the data extracted from the above datasheet.
1. Typical Capacity - 2.6 Ah
2. Minimum Capacity - 2.5 Ah
3. Internal Impedance - 35mΩ
4. Nominal Voltage - 3.6 V
5. Charge Cut-off Voltage - 4.2 V
6. Discharge Cut-off Voltage - 2.75 V
7. Standard Charge Current - 1.3 A
8. Standard Discharge Current - 2.6 A
9. Max Charge Current - 2.6 A
10. Max Discharge Current - 10.4 A
In the above graph , the point located is where the nominal area starts and the Voltage at that point is 3.75 with capacity being 0.7Ah
The above graph shows the life cycle of the cell.
Following are the extracts :
For charging at 0.5C and discharging at 1C, cycle life : 1000
For charging at 0.5C and discharging at 4C, cycle life : 800
For charging at 0.5 C and discharging at 1C, cycle life : 1000
Battery Configuration :
The generic battery model in simulink looks as follows :
Configuration is as follows :
1.General parameters.
The data extracted from data sheet has been filed in the block for configuration.
2. Discharge parameters
3. Aging parameters :
Simulated discharge plot in simulink :