Defining the Randles Parameters
Once the tabs structure is created, the relevant *EM_RANDLES keywords can be generated to model the battery internal Randles circuits, by providing the following:
Randles circuit core parameters:
Defines the following Randles circuit parameters from cards 1 and 2 in the corresponding *EM_RANDLES keyword based on the selected modeling scale (*EM_RANDLES_SOLID, *EM_RANDLES_TSHELL, *EM_RANDLES_BATMAC or *EM_RANDLES_MESHLESS):
- RDLAREA (not applicable for *EM_RANDLES_MESHLESS), Q, SOCINT, CQ, SOCTOU
The following fields, defining the cell structure parts or part sets, will automatically be set by the tool:
- CPPART, CCNPART, SEPPART, PELPART, NELPART in *EM_RANDLES_SOLID
- PSID in *EM_RANDLES_TSHELL and *EM_RANDLES_BATMAC
Randles circuit charge/discharge properties:
Defines RDLTYPE from card 1 and the charge/discharge parameters from cards 3.a and 3.b.
Only the required parameters will be displayed based on the selected Randles circuit type (RDLTYPE), and each parameter can be defined either as a constant or a curve by selecting the corresponding toggle button. If the same definition type is required for all parameters then you can turn on the Use same definition for all parameters option and select the desired global definition mode.
Randles circuit temperature properties:
Defines the following Randles circuit thermal parameters from the optional card 4:
- FRTHER (not applicable for *EM_RANDLES_MESHLESS), TEMP, TEMPU, DUDT, R0TOTH (not applicable for *EM_RANDLES_MESHLESS)
Defines the following Randles circuit SOC shift parameters from the optional card 5:
- USESOCS, TAU, FLCID
Once all values are provided, clicking on Create, will create an *EM_RANDLES (*EM_RANDLES_SOLID, *EM_RANDLES_TSHELL, *EM_RANDLES_BATMAC or *EM_RANDLES_MESHLESS) instance for each unit cell created at step 2.
Additionally, if in Meshless connected to Macro structure mode, for each unit cell, two *EM_ISOPOTENTIAL instances will be generated containing the tab nodes overlapping with the cell (one for each tab) and the two *EM_ISOPOTENTIALs will be connected through an *EM_ISOPOTENTIAL_CONNECT with CONTYPE = 5 and will reference the associated *EM_RANDLES_MESHLESS entry.
The RDLTYPE field in the generated *EM_ISOPOTENTIAL cards will take the following values:
| *EM_ISOPOTENTIAL instance | RDLTYPE |
|---|---|
| Meshless *EM_ISOPOTENTIAL for positive tab nodes | 0: Default (not a cell layer) |
| Meshless *EM_ISOPOTENTIAL for negative tab nodes | 0: Default (not a cell layer) |
The CONTYPE, ISOID1, ISOID2 and RDLID fields in the generated *EM_ISOPOTENTIAL_CONNECT cards for the Meshless scale will take the following values:
| *EM_ISOPOTENTIAL_CONNECT instances | CONTYPE | ISOID1 | ISOID2 | RDLID |
|---|---|---|---|---|
| *EM_ISOPOTENTIAL_CONNECT for connecting Meshless Randles circuit model to Macro structure | 5: Meshless Randles circuit | Meshless *EM_ISOPOTENTIAL for cell node connected to tab 1 | Meshless *EM_ISOPOTENTIAL for cell node connected to tab 2 | *EM_RANDLES_MESHLESS instance generated by the tool |
If you wish to make any modifications to the Randles paramters once created, click on the Edit button to delete all the created entities, update the parameters as desired and click on Create again.
Once satisfied with the Randles parameters, you can move to the '5. Analysis' step by either clicking on the corresponding button at the top of the window, or using the Next button. You can also move back to a previous stage using the Previous button.
