# Scalability of Battery Model R-only

**URL:** <https://forum.plexim.com/t/scalability-of-battery-model-r-only/1802>\
**Category:** PLECS\
**Tags:** battery, lithium-ion\
**Created:** [February 18, 2025, 8:04pm UTC](https://forum.plexim.com/t/scalability-of-battery-model-r-only/1802 "2025-02-18T20:04:43Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![pwreng](https://avatars.discourse-cdn.com/v4/letter/p/f17d59/32.png) [@pwreng](https://forum.plexim.com/u/pwreng)\
**Post date:** [February 18, 2025, 8:04pm UTC](https://forum.plexim.com/t/scalability-of-battery-model-r-only/1802/1 "2025-02-18T20:04:43Z")

</div>

I’m trying to model a large EV battery. Say a few hundred volts and a few hundred amps. After change numerous parameters in the model, without success, I reduced it to a bare minimum of changes from the demo model. I’d like my first effort to be 100 series cells and 100 parallel cells, but model sets the battery voltage to zero, To eliminate any issues with the charger parameters, i’ve eliminated it and simply discharge into a resistor. I been all through the subcircuits, yet still cannot find the problem. Attach are my ultra-simplified models. One with the demo’s 10\*10 battery, and the other one with only two changes, 100 series, 100 parallel  
[Li\_ion\_RonlyModel 10\*10.plecs](https://forum.plexim.com/uploads/short-url/wW8a4pFrSLzZjUYnf56c86es0tx.plecs) (76.2 KB)  
[Li\_ion\_RonlyModel 100\*100.plecs](https://forum.plexim.com/uploads/short-url/1ZILVkYAK5f3vu12jCRGmRvsFub.plecs) (75.9 KB)

---

<div class="post-metadata">

**Author:** ![EnriquePLECS](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/enriqueplecs/32/2276_2.png) [@EnriquePLECS](https://forum.plexim.com/u/EnriquePLECS)\
**Post date:** [February 19, 2025, 1:33pm UTC](https://forum.plexim.com/t/scalability-of-battery-model-r-only/1802/2 "2025-02-19T13:33:15Z")

</div>

Well the problem is that the for the number of cells being 100, the output of V\_OC calculation is -206V, so it gets limited at 0V due to the saturation blocks.

The problem seems to be the “polarizing voltage” calculation which calculates 514V somehow. What is wrong there? I have no idea, since I am not familiar with those equations you should debug it. For the case where the number of cells is 10, the polarizing voltage is smaller than the E\_0, so the calculation yields positive voltage.

 ![Screenshot 2025-02-19 at 14.25.24](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/2X/6/6763c02791f591b67f8b2f44fb818904d75bb701.jpeg)

---

<div class="post-metadata">

**Author:** ![pwreng](https://avatars.discourse-cdn.com/v4/letter/p/f17d59/32.png) [@pwreng](https://forum.plexim.com/u/pwreng)\
**Post date:** [February 20, 2025, 9:14pm UTC](https://forum.plexim.com/t/scalability-of-battery-model-r-only/1802/3 "2025-02-20T21:14:30Z")

</div>

I agree that the “polarizing voltage” calculation is incorrect. It may be related to the K variable. If I manually change its value to something lower, then there is some resemblance of functionality. But without knowledge of exactly K represents, I’m just working blindly. I do have the whitepaper about this model, and it is helpful.  
I am a newbe with PLECS. I cannot find where in the model or any in of the subsystems where certain variables are set. For instance, A, B, K, E\_0. They all have values that I can display, but I cannot find anything that sets them.