# General **URL:** https://pybamm.discourse.group/c/general/4.md [Latest](https://pybamm.discourse.group/latest.md) · [Categories](https://pybamm.discourse.group/categories.md) · [Tags](https://pybamm.discourse.group/tags.md) --- ## [Welcome to PyBaMM! 👋](https://pybamm.discourse.group/t/welcome-to-pybamm/5)
**Author:** [@system](https://pybamm.discourse.group/u/system)\ **Replies:** 0\ **Last updated:** [6 September 2024 03:06 UTC](https://pybamm.discourse.group/t/welcome-to-pybamm/5 "2024-09-06T03:06:32Z")
We are so glad you joined us. PyBaMM A place to discuss and ask questions about PyBaMM and its ecosystem. Here are some things you can do to get started: :speaking\_head: Introduce yourself by adding your picture and… --- ## [About the General category](https://pybamm.discourse.group/t/about-the-general-category/3)
**Author:** [@system](https://pybamm.discourse.group/u/system)\ **Replies:** 0\ **Last updated:** [6 September 2024 03:06 UTC](https://pybamm.discourse.group/t/about-the-general-category/3 "2024-09-06T03:06:31Z")
Create topics here that don’t fit into any other existing category. --- ## [Starting times between cycles](https://pybamm.discourse.group/t/starting-times-between-cycles/484)
**Author:** [@geri](https://pybamm.discourse.group/u/geri)\ **Replies:** 6\ **Last updated:** [30 September 2026 14:32 UTC](https://pybamm.discourse.group/t/starting-times-between-cycles/484 "2026-09-30T14:32:14Z")
Hello, everyone! I’m relative new to Pybamm. I’m working on a parallel-in-time methods. I’ve noticed some differences in the starting times in the solution of an experiment with more than 1 cycle. Here is a small examp… --- ## [Oxygen Diffusion submodel](https://pybamm.discourse.group/t/oxygen-diffusion-submodel/216)
**Author:** [@Salah](https://pybamm.discourse.group/u/Salah)\ **Replies:** 3\ **Last updated:** [10 July 2026 11:07 UTC](https://pybamm.discourse.group/t/oxygen-diffusion-submodel/216 "2026-07-10T11:07:17Z")
hello, can someone help me with my code i tried several ways to plot the Oxygen concentration but have’nt succed \`import pybamm model = pybamm.lithium\_ion.DFN() Set up the oxygen diffusion submodel oxygen\_diffusion … --- ## [How to extract parameter values from a battery?](https://pybamm.discourse.group/t/how-to-extract-parameter-values-from-a-battery/462)
**Author:** [@Jordan354](https://pybamm.discourse.group/u/Jordan354)\ **Replies:** 1\ **Last updated:** [16 April 2026 16:47 UTC](https://pybamm.discourse.group/t/how-to-extract-parameter-values-from-a-battery/462 "2026-04-16T16:47:10Z")
Good Afternoon all, I want to replicate the charge, discharge, and cycle characteristics of a known cell, the Molicel P45B, in PyBaMM. I have their data sheet here. INR21700P45B\_1.2\_Product-Data-Sheet-of-INR-21700-P45B… --- ## [Pybamm discourse group activity](https://pybamm.discourse.group/t/pybamm-discourse-group-activity/455)
**Author:** [@Thiyaga](https://pybamm.discourse.group/u/Thiyaga)\ **Replies:** 0\ **Last updated:** [14 March 2026 07:13 UTC](https://pybamm.discourse.group/t/pybamm-discourse-group-activity/455 "2026-03-14T07:13:28Z")
Hi All, I see there are many questions/queries remain unanswered in the discourse group. Humble request to all members, can anything be done about this so that the group becomes more active and helpful. thanks and rega… --- ## [Size mismatch between variables](https://pybamm.discourse.group/t/size-mismatch-between-variables/448)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 0\ **Last updated:** [5 February 2026 15:56 UTC](https://pybamm.discourse.group/t/size-mismatch-between-variables/448 "2026-02-05T15:56:40Z")
I have a rather basic question about how PyBAMM handles discretizations. From what I understand the gradient of a variable pybamm.grad(c), has shape N-1. Now, if this gradient is to be multiplied by a function parameter… --- ## [Question about grouped parameter models](https://pybamm.discourse.group/t/question-about-grouped-parameter-models/446)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 0\ **Last updated:** [29 January 2026 16:12 UTC](https://pybamm.discourse.group/t/question-about-grouped-parameter-models/446 "2026-01-29T16:12:29Z")
Hello, I am lookin at the grouped parameter model examples provided in PyBOB (PyBOP/pybop/models/lithium\_ion/grouped\_spme.py at develop · pybop-team/PyBOP · GitHub), for both SPM and SPMe models. I have a question about … --- ## [Initial temperature input does not work](https://pybamm.discourse.group/t/initial-temperature-input-does-not-work/435)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 1\ **Last updated:** [23 January 2026 18:42 UTC](https://pybamm.discourse.group/t/initial-temperature-input-does-not-work/435 "2026-01-23T18:42:59Z")
Hi, I have seen this entry on GitHub where PyBamm is used to solve the electrical problem, while the thermal problem is handled in Simulink (GitHub - FaradayInstitution/pybamm\_simulink\_example: An example of how to run p… --- ## [Discrepancy Between “Total heating \[W\]” by PyBaMM and Bernardi Formula in Lumped Thermal Models](https://pybamm.discourse.group/t/discrepancy-between-total-heating-w-by-pybamm-and-bernardi-formula-in-lumped-thermal-models/316)
**Author:** [@kazuma](https://pybamm.discourse.group/u/kazuma)\ **Replies:** 1\ **Last updated:** [23 January 2026 16:45 UTC](https://pybamm.discourse.group/t/discrepancy-between-total-heating-w-by-pybamm-and-bernardi-formula-in-lumped-thermal-models/316 "2026-01-23T16:45:05Z")
Hello, I have some questions regarding the calculation of heat generation in the lumped thermal model. In PyBaMM, the heat generation is calculated using information such as the exchange current density and electrode po… --- ## [How do we use the hysteresis for LFP cathode with single phase Negative electrode](https://pybamm.discourse.group/t/how-do-we-use-the-hysteresis-for-lfp-cathode-with-single-phase-negative-electrode/431)
**Author:** [@Masood](https://pybamm.discourse.group/u/Masood)\ **Replies:** 1\ **Last updated:** [23 January 2026 15:46 UTC](https://pybamm.discourse.group/t/how-do-we-use-the-hysteresis-for-lfp-cathode-with-single-phase-negative-electrode/431 "2026-01-23T15:46:27Z")
Help to implement the hysteresis by telling what needs to be changed specifically with respect to pybamm. where i can find the hysteresis raw code? --- ## [Using pixi as an option to build PyBaMM](https://pybamm.discourse.group/t/using-pixi-as-an-option-to-build-pybamm/443)
**Author:** [@prady0t](https://pybamm.discourse.group/u/prady0t)\ **Replies:** 0\ **Last updated:** [20 January 2026 12:33 UTC](https://pybamm.discourse.group/t/using-pixi-as-an-option-to-build-pybamm/443 "2026-01-20T12:33:28Z")
Are there any ongoing efforts to adopt Pixi for infra (tests, builds, CI, etc)? It might be worth the effort. See: https://pixi.sh/latest/ --- ## [Half-cell model with SEI growth](https://pybamm.discourse.group/t/half-cell-model-with-sei-growth/432)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 0\ **Last updated:** [8 January 2026 14:43 UTC](https://pybamm.discourse.group/t/half-cell-model-with-sei-growth/432 "2026-01-08T14:43:22Z")
Hi, I am wondering how could I implement a SEI growth model in the Li-metal side in a PyBAMM half-cell model. I am not finding a direct way of doing it. Maybe I need to resort to building a custom model? --- ## [DFN model variables](https://pybamm.discourse.group/t/dfn-model-variables/430)
**Author:** [@Fark](https://pybamm.discourse.group/u/Fark)\ **Replies:** 0\ **Last updated:** [6 January 2026 13:34 UTC](https://pybamm.discourse.group/t/dfn-model-variables/430 "2026-01-06T13:34:09Z")
Hi, I would like to understand the difference between “Environment total cooling \[W\]” and “Surface total cooling \[W\]”. Which one is suitable to opt for in case of a lumped thermal model? I am obtaining a flat line when … --- ## [Error with pybamm base thermal model source code](https://pybamm.discourse.group/t/error-with-pybamm-base-thermal-model-source-code/419)
**Author:** [@alex.0249](https://pybamm.discourse.group/u/alex.0249)\ **Replies:** 0\ **Last updated:** [27 November 2025 09:50 UTC](https://pybamm.discourse.group/t/error-with-pybamm-base-thermal-model-source-code/419 "2025-11-27T09:50:01Z")
Hi, Just thought I’d mention that changing the parameter: Negative electrode OCP entropic change \[V.K-1\] to a non-zero value gives the error: ShapeError: Cannot find shape (original error: operands could not be broadc… --- ## [Interpolation using lookup table](https://pybamm.discourse.group/t/interpolation-using-lookup-table/414)
**Author:** [@alex.0249](https://pybamm.discourse.group/u/alex.0249)\ **Replies:** 0\ **Last updated:** [14 November 2025 10:22 UTC](https://pybamm.discourse.group/t/interpolation-using-lookup-table/414 "2025-11-14T10:22:51Z")
Hi, I am trying to develop an function parameter that uses a lookup table of x,y,z to interpolate so that for any x,y value it can output a single z value. However, I get the error: 65 x1, x2 = x 66 if y.ndim != 2: —\>… --- ## [Future model implementations](https://pybamm.discourse.group/t/future-model-implementations/413)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 0\ **Last updated:** [11 November 2025 18:24 UTC](https://pybamm.discourse.group/t/future-model-implementations/413 "2025-11-11T18:24:00Z")
Hi all, I write this just as a general discussion on the plans or next steps for PyBAMM. I know that implementing submodels is pretty straightforward with PyBAMM but I wonder about future plans for developer teams. I am… --- ## [Errors with module jax on Debian 13](https://pybamm.discourse.group/t/errors-with-module-jax-on-debian-13/411)
**Author:** [@oliver.rdz](https://pybamm.discourse.group/u/oliver.rdz)\ **Replies:** 1\ **Last updated:** [6 November 2025 21:12 UTC](https://pybamm.discourse.group/t/errors-with-module-jax-on-debian-13/411 "2025-11-06T21:12:13Z")
Hello. I installed pybamm via pip on a Debian 13 machine, Linux kernel 6.12.48 and with Python 3.13.5. When importing pybamm I get the error “ModuleNotFoundError: No module named ‘jax’”. After forcing the installation … --- ## [SPM model and SEI on cracks issue](https://pybamm.discourse.group/t/spm-model-and-sei-on-cracks-issue/410)
**Author:** [@lenzipl](https://pybamm.discourse.group/u/lenzipl)\ **Replies:** 0\ **Last updated:** [6 November 2025 13:27 UTC](https://pybamm.discourse.group/t/spm-model-and-sei-on-cracks-issue/410 "2025-11-06T13:27:29Z")
I am running a coupled degradation simulation based on the coupled degradation examples page, but using both DFN and SPM models. My code sets “SEI on cracks”: “true” for both models. Both models report very simular valu… --- ## [Can't use pybamm.Interpolant as input](https://pybamm.discourse.group/t/cant-use-pybamm-interpolant-as-input/403)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 4\ **Last updated:** [24 October 2025 13:23 UTC](https://pybamm.discourse.group/t/cant-use-pybamm-interpolant-as-input/403 "2025-10-24T13:23:23Z")
When trying to use a pybamm.Interpolant as an input argument to the solve() method. parameter\_values\[“Current function \[A\]”\] = “\[input\]” interpolant = pybamm.Interpolant(experiment\[:, 0\], experiment\[:, 1\], pybamm.t) … --- ## [Lithium plating reaction overpotential inconsistent with the model definition](https://pybamm.discourse.group/t/lithium-plating-reaction-overpotential-inconsistent-with-the-model-definition/401)
**Author:** [@appana.3](https://pybamm.discourse.group/u/appana.3)\ **Replies:** 1\ **Last updated:** [9 October 2025 00:43 UTC](https://pybamm.discourse.group/t/lithium-plating-reaction-overpotential-inconsistent-with-the-model-definition/401 "2025-10-09T00:43:06Z")
Hello everyone, I am simulating lithium plating with “OKane2022” dataset using SPMe model. As per the documentation given here, I expected that all the values for an arbitrary ‘x’ in the given domain would be the same.… --- ## [Using multithreading for parameter sweeps using experiments](https://pybamm.discourse.group/t/using-multithreading-for-parameter-sweeps-using-experiments/397)
**Author:** [@oarcelus](https://pybamm.discourse.group/u/oarcelus)\ **Replies:** 5\ **Last updated:** [6 October 2025 07:25 UTC](https://pybamm.discourse.group/t/using-multithreading-for-parameter-sweeps-using-experiments/397 "2025-10-06T07:25:17Z")
Hi, I am trying to use the multithreading capabilities of the IKDALU solver to run the model for different parameter sets (varying 5 parameters at the same time for each execution). I am unable to make it work when usin… --- ## [Solver error when running a multi-scale multi-dimensional model](https://pybamm.discourse.group/t/solver-error-when-running-a-multi-scale-multi-dimensional-model/400)
**Author:** [@appana.3](https://pybamm.discourse.group/u/appana.3)\ **Replies:** 4\ **Last updated:** [29 September 2025 13:26 UTC](https://pybamm.discourse.group/t/solver-error-when-running-a-multi-scale-multi-dimensional-model/400 "2025-09-29T13:26:48Z")
I am trying to solve a DFN model with Current collector, thermal, lithium plating, and active material loss submodels. Unfortunately, I cannot share an MWE because the calibration is confidential. I am using the IDAKLU s… --- ## [Is it possible to set the initial SOH?](https://pybamm.discourse.group/t/is-it-possible-to-set-the-initial-soh/398)
**Author:** [@JM\_Zhang](https://pybamm.discourse.group/u/JM_Zhang)\ **Replies:** 1\ **Last updated:** [25 September 2025 22:11 UTC](https://pybamm.discourse.group/t/is-it-possible-to-set-the-initial-soh/398 "2025-09-25T22:11:43Z")
I wish to configure experiments in pybamm to commence under different SOH conditions, but there are no variables pertaining to SOH within the available variables.There is also no direct option to set SOH within the solve… --- ## [Coupling of reaction limited model](https://pybamm.discourse.group/t/coupling-of-reaction-limited-model/376)
**Author:** [@alex.0249](https://pybamm.discourse.group/u/alex.0249)\ **Replies:** 1\ **Last updated:** [4 September 2025 12:55 UTC](https://pybamm.discourse.group/t/coupling-of-reaction-limited-model/376 "2025-09-04T12:55:44Z")
Hi, I am trying to couple the reaction limited SEI growth submodel with LAM and cracking for graphite and another parameter set to fit the degradation using the SEI reaction exchange current. For the OKane paramete set … --- ## [Noisy and implausible capacity fade](https://pybamm.discourse.group/t/noisy-and-implausible-capacity-fade/391)
**Author:** [@laka7552](https://pybamm.discourse.group/u/laka7552)\ **Replies:** 1\ **Last updated:** [4 September 2025 12:47 UTC](https://pybamm.discourse.group/t/noisy-and-implausible-capacity-fade/391 "2025-09-04T12:47:22Z")
Hi all, I am using PyBaMM to set up a DFN with degradation mechanisms (SEI growth, LI plating, particle cracking). I want to evaluate certain thermal management strategies (so different battery temperature) in a discha… --- ## [Extracting intermediate solution object](https://pybamm.discourse.group/t/extracting-intermediate-solution-object/393)
**Author:** [@Thiyaga](https://pybamm.discourse.group/u/Thiyaga)\ **Replies:** 1\ **Last updated:** [4 September 2025 12:45 UTC](https://pybamm.discourse.group/t/extracting-intermediate-solution-object/393 "2025-09-04T12:45:26Z")
hi all, I am running an aging simulation with charge/discharge cycles for 2000 cycles. I want to extract intermediate solution object at cycles 500, 1000 and 1500 and use them as starting solution for another aging prot… --- ## [Last\_state syntax in PYBAMM25.6](https://pybamm.discourse.group/t/last-state-syntax-in-pybamm25-6/374)
**Author:** [@Thiyaga](https://pybamm.discourse.group/u/Thiyaga)\ **Replies:** 0\ **Last updated:** [5 August 2025 14:12 UTC](https://pybamm.discourse.group/t/last-state-syntax-in-pybamm25-6/374 "2025-08-05T14:12:55Z")
Hi, I want to use solution property ‘last\_state’ to save memory but don’t know how to give the command. I tried, starting\_solution=solutions.last\_state, but got below error message, CoordinateValidationError: confl… --- ## [Solver error when increasing degradation of graphite parameters](https://pybamm.discourse.group/t/solver-error-when-increasing-degradation-of-graphite-parameters/369)
**Author:** [@alex.0249](https://pybamm.discourse.group/u/alex.0249)\ **Replies:** 7\ **Last updated:** [29 July 2025 11:13 UTC](https://pybamm.discourse.group/t/solver-error-when-increasing-degradation-of-graphite-parameters/369 "2025-07-29T11:13:44Z")
Hi, I keep getting the solver error: 2025-07-25 10:44:02.905 - \[ERROR\] callbacks.on\_experiment\_error(233): Simulation error: FAILURE IDA\_CONV\_FAIL: Convergence test failures occurred too many times during one internal … --- ## [Effect of temperature on aging](https://pybamm.discourse.group/t/effect-of-temperature-on-aging/92)
**Author:** [@Thiyaga](https://pybamm.discourse.group/u/Thiyaga)\ **Replies:** 4\ **Last updated:** [12 July 2025 10:58 UTC](https://pybamm.discourse.group/t/effect-of-temperature-on-aging/92 "2025-07-12T10:58:48Z")
I am running an aging simulation at 25 deg and 35 degC with following options, model = pybamm.lithium\_ion.SPM( { “cell geometry”: “arbitrary”, “thermal”: “lumped”, “SEI”: “solvent-diffusion limited”, “SEI porosity … [Next page](https://pybamm.discourse.group/c/general/4.md?page=1)