Learning Forum

[Harsh Lakkalkatti]

Hello,

I have been trying to use the battery MSMD model (I'm using Ansys 2023R1) for my LFP 32700 cell. I have been referring to this YouTube series. I have a few questions:

1. Is the equivalent circuit model limited to 2RC circuits? I'm unable to go higher, can someone please help me go from 2 to 3-5 RC inputs?

2. In material properties, where did the UDS diffusivity option go? It used to exist in earlier versions but is not shown under material properties in Ansys 2023 R1. Can someone please tell me where to input my UDS of materials?

Before:



In Ansys 2023R1:



I look forward to your answers and interacting with you. Thank you for your time.

[Murari Iyengar]

 

Hi Harsh,

 

1. You have 2 options the ECM model, to use 4P model (1 RC) or 6P model (2 RC). If you want to use higher RCs, this will require you to write a UDF with all the battery related equations.
2. In the newer versions, UDS Diffusivity is changed to Electrical Conductivity. In the sub-options, you can choose Defined-per-uds. 

 

 

[Harsh Lakkalkatti]

@Murari Iyengar, Thanks for your response.

I had one doubt about the UDF Diffusivity. In the photos that I've shared, the previous versions say "UDF Diffusivity in kg/m-s". How is this unit related to Electrical conductivity in 2023R1 version, which is in S/m? Aren't these completely different things with different units? I didn't understand how I can put values from previous versions in kg/m-s, and 2023R1 in S/m. Can you please give me some clarity in terms of units,definitions or conversion of the numbers (from kg/m-s to S/m if any). 

Thank you so much for your time.