# General **URL:** https://pybamm.discourse.group/c/general/4.md?page=1 [Latest](https://pybamm.discourse.group/latest.md) · [Categories](https://pybamm.discourse.group/categories.md) · [Tags](https://pybamm.discourse.group/tags.md) **Page:** 2 --- ## [Problem with cell capacity](https://pybamm.discourse.group/t/problem-with-cell-capacity/356)
**Author:** [@Salah](https://pybamm.discourse.group/u/Salah)\ **Replies:** 0\ **Last updated:** [26 June 2025 07:54 UTC](https://pybamm.discourse.group/t/problem-with-cell-capacity/356 "2025-06-26T07:54:33Z")
Hello, I am trying the diffrent SEI growth mecanism that are being used in pybamm at diffrent temperatures, th issue that I’m facing is that when I use my cell parametres during cycling i get the cell capacity without i… --- ## [Calendar aging of lithium ion batteries](https://pybamm.discourse.group/t/calendar-aging-of-lithium-ion-batteries/344)
**Author:** [@Salah](https://pybamm.discourse.group/u/Salah)\ **Replies:** 2\ **Last updated:** [25 June 2025 07:25 UTC](https://pybamm.discourse.group/t/calendar-aging-of-lithium-ion-batteries/344 "2025-06-25T07:25:48Z")
Hello, I’m trying to study the effect of the SEI on calendar aging and i Dont know what type of experimental protocol i should use in pybamm. If any one can provide me with a standard protocol i would be greartfull. T… --- ## [Fitting Battery Degradation: Across Different C-rates and Temperatures](https://pybamm.discourse.group/t/fitting-battery-degradation-across-different-c-rates-and-temperatures/296)
**Author:** [@t-schilt](https://pybamm.discourse.group/u/t-schilt)\ **Replies:** 2\ **Last updated:** [24 June 2025 09:06 UTC](https://pybamm.discourse.group/t/fitting-battery-degradation-across-different-c-rates-and-temperatures/296 "2025-06-24T09:06:52Z")
I’ve been working with LG21700 battery cycling data (current, voltage, charge and discharge capacity, time steps) collected experimentally at different C-rates (0.5C, 1C, 2C) and temperatures (10°C, 20°C, 40°C). Now I’m … --- ## [Returning solution at requested times with IDAKLU solver](https://pybamm.discourse.group/t/returning-solution-at-requested-times-with-idaklu-solver/346)
**Author:** [@isaac\_basil](https://pybamm.discourse.group/u/isaac_basil)\ **Replies:** 1\ **Last updated:** [16 June 2025 14:01 UTC](https://pybamm.discourse.group/t/returning-solution-at-requested-times-with-idaklu-solver/346 "2025-06-16T14:01:49Z")
Hi, Up until now I have been using the Casadi solver. I provided t\_eval as an array of time values to the solve method, and Casadi returned the solution at those time values. When I do this with IDAKLU, it doesn’t beha… --- ## [Impementation spm and model using chen2020 parameters](https://pybamm.discourse.group/t/impementation-spm-and-model-using-chen2020-parameters/341)
**Author:** [@SIMPORE](https://pybamm.discourse.group/u/SIMPORE)\ **Replies:** 0\ **Last updated:** [13 June 2025 13:58 UTC](https://pybamm.discourse.group/t/impementation-spm-and-model-using-chen2020-parameters/341 "2025-06-13T13:58:43Z")
Hello dear members, I am Dieudonné SIMPORE, a PhD student at Joseph Ki-ZERBO University. I use PyBaMM extensively for my work and find the content truly fascinating. My issue is that I am trying to implement the SPM mode… --- ## [Step-wise current using PyBaMM v 25.6.0](https://pybamm.discourse.group/t/step-wise-current-using-pybamm-v-25-6-0/339)
**Author:** [@Lucas](https://pybamm.discourse.group/u/Lucas)\ **Replies:** 0\ **Last updated:** [12 June 2025 18:46 UTC](https://pybamm.discourse.group/t/step-wise-current-using-pybamm-v-25-6-0/339 "2025-06-12T18:46:02Z")
I’m trying to simulate a battery with a step-wise current profile using PyBaMM version 25.6.0. I’ve defined a function to represent the current that changes value at a specific time. However, when I assign this function … --- ## [Issue with PyBaMM installation using pyproject.toml file](https://pybamm.discourse.group/t/issue-with-pybamm-installation-using-pyproject-toml-file/334)
**Author:** [@appana.3](https://pybamm.discourse.group/u/appana.3)\ **Replies:** 2\ **Last updated:** [4 June 2025 16:02 UTC](https://pybamm.discourse.group/t/issue-with-pybamm-installation-using-pyproject-toml-file/334 "2025-06-04T16:02:05Z")
Hi, I am trying to install all the requirements and dependencies for PyBaMM v25.4.2 using the source repository available on Github. I tried creating a virtual environment that would automatically install the requiremen… --- ## [Discrepancy between pybamm inner and numpy inner](https://pybamm.discourse.group/t/discrepancy-between-pybamm-inner-and-numpy-inner/331)
**Author:** [@derek](https://pybamm.discourse.group/u/derek)\ **Replies:** 0\ **Last updated:** [27 May 2025 19:28 UTC](https://pybamm.discourse.group/t/discrepancy-between-pybamm-inner-and-numpy-inner/331 "2025-05-27T19:28:40Z")
I was wondering the reasoning for this discrepancy between the Pybamm Inner product and the numpy inner product import pybamm import numpy as np a = np.array(\[1,2,3,4,5\]) b = np.array(\[5,4,3,2,1\]) c\_pb = pybamm.Inner(… --- ## [Why does CCCV charging result in more capacity loss than constant current in a single cycle?](https://pybamm.discourse.group/t/why-does-cccv-charging-result-in-more-capacity-loss-than-constant-current-in-a-single-cycle/328)
**Author:** [@squirrel](https://pybamm.discourse.group/u/squirrel)\ **Replies:** 4\ **Last updated:** [27 May 2025 13:02 UTC](https://pybamm.discourse.group/t/why-does-cccv-charging-result-in-more-capacity-loss-than-constant-current-in-a-single-cycle/328 "2025-05-27T13:02:41Z")
I’m investigating the trade-off between CCCV and constant current (CC) charging strategies by observing the capacity loss due to side reactions over a single charging cycle. Surprisingly, I found that the capacity loss … --- ## [About the solver](https://pybamm.discourse.group/t/about-the-solver/329)
**Author:** [@shubh](https://pybamm.discourse.group/u/shubh)\ **Replies:** 1\ **Last updated:** [22 May 2025 17:41 UTC](https://pybamm.discourse.group/t/about-the-solver/329 "2025-05-22T17:41:53Z")
which is currently the default solver in Pybamm ? In Pybamm doc , Cascadi is mentioned as default . Is Idaklu new default solver? Please verify this. --- ## [Optimizing Mesh Size for Smooth Voltage Profiles in aging simulations](https://pybamm.discourse.group/t/optimizing-mesh-size-for-smooth-voltage-profiles-in-aging-simulations/324)
**Author:** [@davimoli](https://pybamm.discourse.group/u/davimoli)\ **Replies:** 1\ **Last updated:** [17 May 2025 11:59 UTC](https://pybamm.discourse.group/t/optimizing-mesh-size-for-smooth-voltage-profiles-in-aging-simulations/324 "2025-05-17T11:59:51Z")
Hi everyone, I’m simulating the aging of an LG M50T 21700 cylindrical cell using a DFN model with ORegan2022 parameters and OKane2022 degradation parameters. My goal is to analyze the voltage profile during CC-CCCV cycl… --- ## [Modelisation avec Pybamm](https://pybamm.discourse.group/t/modelisation-avec-pybamm/322)
**Author:** [@youssoupha](https://pybamm.discourse.group/u/youssoupha)\ **Replies:** 0\ **Last updated:** [7 May 2025 12:07 UTC](https://pybamm.discourse.group/t/modelisation-avec-pybamm/322 "2025-05-07T12:07:08Z")
je cherche à modeliser la batterie avec donnees de mesure de la tension, courant et temperature sur une durees de 4 mois je cherche de l’aide --- ## [Array size incompatible with Jaxified IDAKLU solver](https://pybamm.discourse.group/t/array-size-incompatible-with-jaxified-idaklu-solver/318)
**Author:** [@Cade](https://pybamm.discourse.group/u/Cade)\ **Replies:** 0\ **Last updated:** [29 April 2025 21:38 UTC](https://pybamm.discourse.group/t/array-size-incompatible-with-jaxified-idaklu-solver/318 "2025-04-29T21:38:06Z")
I am following the tutorial for exposing the IDAKLU solver to JAX at IDAKLU-JAX interface — PyBaMM v25.4.3.dev11+g34186fe18 Manual The code tutorial runs fine with output variables that inherently return 1D arrays (Tim… --- ## [Liionpack: Can we do step simulation in for packs just like we do in Pybamm single cell simulation?](https://pybamm.discourse.group/t/liionpack-can-we-do-step-simulation-in-for-packs-just-like-we-do-in-pybamm-single-cell-simulation/314)
**Author:** [@Syed](https://pybamm.discourse.group/u/Syed)\ **Replies:** 0\ **Last updated:** [27 April 2025 23:47 UTC](https://pybamm.discourse.group/t/liionpack-can-we-do-step-simulation-in-for-packs-just-like-we-do-in-pybamm-single-cell-simulation/314 "2025-04-27T23:47:54Z")
I have worked on step simulation in Pybamm for tracking parameters such as SOC, voltage etc. But I am looking for same thing for Liionpack to simulate battery pack using step simulation --- ## [Liionpack running issue in Jupyter Notebook](https://pybamm.discourse.group/t/liionpack-running-issue-in-jupyter-notebook/313)
**Author:** [@Syed](https://pybamm.discourse.group/u/Syed)\ **Replies:** 1\ **Last updated:** [25 April 2025 00:50 UTC](https://pybamm.discourse.group/t/liionpack-running-issue-in-jupyter-notebook/313 "2025-04-25T00:50:46Z")
When I am running a program for Liionpack, it runs nice for 1st time but next time it is also running but it is not plotting anything like 1st time. the code is: try: import liionpack as lp except: !pip install -q gi… --- ## [SOC calculation](https://pybamm.discourse.group/t/soc-calculation/263)
**Author:** [@Syed](https://pybamm.discourse.group/u/Syed)\ **Replies:** 4\ **Last updated:** [25 April 2025 00:46 UTC](https://pybamm.discourse.group/t/soc-calculation/263 "2025-04-25T00:46:37Z")
I am working on battery electrochemical modeling for using in microgrid applications purpose and using the pybamm functions to calculate SOC from model variables. But due to my lack of battery chemistry knowledge, I am u… --- ## [Fitting OCV Curves with Composite tanh and cosh Functions in PyBaMM](https://pybamm.discourse.group/t/fitting-ocv-curves-with-composite-tanh-and-cosh-functions-in-pybamm/304)
**Author:** [@vipulnovo](https://pybamm.discourse.group/u/vipulnovo)\ **Replies:** 1\ **Last updated:** [14 April 2025 15:36 UTC](https://pybamm.discourse.group/t/fitting-ocv-curves-with-composite-tanh-and-cosh-functions-in-pybamm/304 "2025-04-14T15:36:20Z")
Hello PyBaMM Community,​ I’m exploring methods to model the open-circuit voltage (OCV) versus state of charge (SOC) relationship in lithium-ion batteries. I’ve observed that composite functions incorporating hyperbolic … --- ## [How to couple SIB basic DFN with a thermal model?](https://pybamm.discourse.group/t/how-to-couple-sib-basic-dfn-with-a-thermal-model/300)
**Author:** [@Rookie](https://pybamm.discourse.group/u/Rookie)\ **Replies:** 0\ **Last updated:** [10 April 2025 12:07 UTC](https://pybamm.discourse.group/t/how-to-couple-sib-basic-dfn-with-a-thermal-model/300 "2025-04-10T12:07:35Z")
Hello, I am a student and I want to simulate a Sodium-Ion Battery (SIB) using the sodium\_ion.BasicDFN model. I want to couple it with a lumped thermal submodel, but it doesn’t work. I am quite sure it’s because of the m… --- ## [Deg Modes don't make sense](https://pybamm.discourse.group/t/deg-modes-dont-make-sense/279)
**Author:** [@J-Py](https://pybamm.discourse.group/u/J-Py)\ **Replies:** 5\ **Last updated:** [7 April 2025 06:59 UTC](https://pybamm.discourse.group/t/deg-modes-dont-make-sense/279 "2025-04-07T06:59:39Z")
Hi, I have run some degradation sims and would like to plot the loss in capacity \[Ah\] for each degradation mode (LLI, LAM\_NE, LAM\_PE) as the cell ages. I am aware that the deg. modes are available in \[%\] decrease (i… --- ## [SoC and energy balance using PyBaMM](https://pybamm.discourse.group/t/soc-and-energy-balance-using-pybamm/286)
**Author:** [@Chavan073](https://pybamm.discourse.group/u/Chavan073)\ **Replies:** 0\ **Last updated:** [31 March 2025 18:53 UTC](https://pybamm.discourse.group/t/soc-and-energy-balance-using-pybamm/286 "2025-03-31T18:53:52Z")
Hello! I just started using PyBaMM and am trying to model a battery and plot the SOC over a 24-hour day. I am pulling data from a load profile I created in Excel (Time and Load \[kW\]). The model should step through the… --- ## [Error while running simulations with IDAKLU solver and "dimensionality: 2" on Windows using the latest PyBaMM version](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240)
**Author:** [@appana.3](https://pybamm.discourse.group/u/appana.3)\ **Replies:** 4\ **Last updated:** [31 March 2025 15:41 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240 "2025-03-31T15:41:32Z")
Hello, Find below a MWE of the problem I have. When I run this, I get the error shown! import pybamm options = {"dimensionality": 2, "current collector": "potential pair"} model = pybamm.lithium\_ion.DFN(options=options… --- ## [Ambient Temprature of a battery (under low temp)](https://pybamm.discourse.group/t/ambient-temprature-of-a-battery-under-low-temp/284)
**Author:** [@Guri](https://pybamm.discourse.group/u/Guri)\ **Replies:** 2\ **Last updated:** [31 March 2025 10:57 UTC](https://pybamm.discourse.group/t/ambient-temprature-of-a-battery-under-low-temp/284 "2025-03-31T10:57:55Z")
Hello, I am trying to simulate a battery under cold temprature, somewhere around 263.15 K. When I simulate the battery at room temprature it is giving me a desired discharge capacity vs cycle number graph. However, when… --- ## [Is there any defulted side reaction model?](https://pybamm.discourse.group/t/is-there-any-defulted-side-reaction-model/249)
**Author:** [@xyyrly](https://pybamm.discourse.group/u/xyyrly)\ **Replies:** 4\ **Last updated:** [31 March 2025 09:33 UTC](https://pybamm.discourse.group/t/is-there-any-defulted-side-reaction-model/249 "2025-03-31T09:33:46Z")
Hi all, I am runing an aging model in pybamm considering various side reactions. I thought the following model setting, i.e., model = pybamm.lithium\_ion.DFN( { “SEI”: “none”, “SEI porosity change”: “false”, “lithiu… --- ## [Blend\_electode modelling](https://pybamm.discourse.group/t/blend-electode-modelling/247)
**Author:** [@Anfal](https://pybamm.discourse.group/u/Anfal)\ **Replies:** 2\ **Last updated:** [28 March 2025 07:59 UTC](https://pybamm.discourse.group/t/blend-electode-modelling/247 "2025-03-28T07:59:43Z")
Hi everyone, I’m running a PyBaMM simulation and trying to define a custom exchange current density function for the secondary positive electrode. The function works when I input values manually, but when I pass it as a… --- ## [Memory and Performance Issues with starting\_solution in PyBaMM for RL Environment](https://pybamm.discourse.group/t/memory-and-performance-issues-with-starting-solution-in-pybamm-for-rl-environment/270)
**Author:** [@squirrel](https://pybamm.discourse.group/u/squirrel)\ **Replies:** 4\ **Last updated:** [27 March 2025 02:34 UTC](https://pybamm.discourse.group/t/memory-and-performance-issues-with-starting-solution-in-pybamm-for-rl-environment/270 "2025-03-27T02:34:41Z")
Hello, I’m trying to use PyBaMM to build a reinforcement learning environment, but I’ve encountered an issue. To allow the current to change in real-time based on the values provided by the agent, I adopted the followin… --- ## [Discrepancies Between DFN and SPMe Cyclic Aging Results](https://pybamm.discourse.group/t/discrepancies-between-dfn-and-spme-cyclic-aging-results/275)
**Author:** [@fgh](https://pybamm.discourse.group/u/fgh)\ **Replies:** 0\ **Last updated:** [26 March 2025 02:42 UTC](https://pybamm.discourse.group/t/discrepancies-between-dfn-and-spme-cyclic-aging-results/275 "2025-03-26T02:42:24Z")
I utilized the standard Constant Current Constant Voltage (CCCV) method to conduct cycle charge and discharge tests, using the same parameters and setting as outlined in OKane 2022. The code is provided below. It is evid… --- ## [Unreasonable capacity loss of long life modeling](https://pybamm.discourse.group/t/unreasonable-capacity-loss-of-long-life-modeling/219)
**Author:** [@nuanyuan](https://pybamm.discourse.group/u/nuanyuan)\ **Replies:** 1\ **Last updated:** [25 March 2025 16:33 UTC](https://pybamm.discourse.group/t/unreasonable-capacity-loss-of-long-life-modeling/219 "2025-03-25T16:33:10Z")
hello, can someone help me with figuring out the unreasonable capacity loss of long life modeling. I am doing long cycle life modeling on my own cell with relatively large capacity. The parameters were based on Mohtat2… --- ## [Capacity of simulation and experimental plot not matching](https://pybamm.discourse.group/t/capacity-of-simulation-and-experimental-plot-not-matching/100)
**Author:** [@shubh](https://pybamm.discourse.group/u/shubh)\ **Replies:** 26\ **Last updated:** [24 March 2025 16:00 UTC](https://pybamm.discourse.group/t/capacity-of-simulation-and-experimental-plot-not-matching/100 "2025-03-24T16:00:52Z")
Hii i am trying to simulate capacity and match it with experimental data. But there is huge difference in plot. What change can be done to match both the plot . import pybamm import numpy as np import matplotlib.py… --- ## [Simulation of battery charging](https://pybamm.discourse.group/t/simulation-of-battery-charging/261)
**Author:** [@Salah](https://pybamm.discourse.group/u/Salah)\ **Replies:** 2\ **Last updated:** [24 March 2025 15:47 UTC](https://pybamm.discourse.group/t/simulation-of-battery-charging/261 "2025-03-24T15:47:29Z")
Hello everyone, I’m trying to simulate battery charging with no cycles but it always starte from 4.2V . If i try to hold at 3.3V for example it gives me a vertical curve untile 4.2V --- ## [Error while executing the code](https://pybamm.discourse.group/t/error-while-executing-the-code/258)
**Author:** [@abhaygudi](https://pybamm.discourse.group/u/abhaygudi)\ **Replies:** 0\ **Last updated:** [23 March 2025 12:24 UTC](https://pybamm.discourse.group/t/error-while-executing-the-code/258 "2025-03-23T12:24:38Z")
hi, Please go through my attached code. I am getting following error when I execute it. CasADi - 2025-03-23 17:47:14 WARNING("The options ‘t0’, ‘tf’, ‘grid’ and ‘output\_t0’ have been deprecated. The same functionality … [Previous page](https://pybamm.discourse.group/c/general/4.md) [Next page](https://pybamm.discourse.group/c/general/4.md?page=2)