diff --git a/README.md b/README.md
index 9f31488f5..a6857b96d 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,8 @@ PyBaMM comes with a number of [detailed examples](examples/README.md), hosted he
 
 ## How can I install PyBaMM?
 
+The safest way to install PyBaMM is to do so within a virtual environment ([introduction to virtual environments](https://realpython.com/python-virtual-environments-a-primer/))
+
 You'll need the following requirements:
 
 - Python 3.5+
diff --git a/pybamm/__init__.py b/pybamm/__init__.py
index d86a8349f..4ee569b8e 100644
--- a/pybamm/__init__.py
+++ b/pybamm/__init__.py
@@ -84,7 +84,7 @@ from .expression_tree.unary_operators import (
     div,
     surf,
     Diagonal,
-    integrate
+    integrate,
 )
 from .expression_tree.parameter import Parameter, FunctionParameter
 from .expression_tree.broadcasts import Broadcast, NumpyBroadcast
diff --git a/pybamm/models/base_models.py b/pybamm/models/base_models.py
index 5196adc57..df43b6926 100644
--- a/pybamm/models/base_models.py
+++ b/pybamm/models/base_models.py
@@ -111,7 +111,10 @@ class BaseModel(object):
             "negative particle": pybamm.FiniteVolume,
             "positive particle": pybamm.FiniteVolume,
         }
-        self.default_solver = pybamm.ScikitsOdeSolver()
+        try:
+            self.default_solver = pybamm.ScikitsOdeSolver()
+        except ImportError:
+            self.default_solver = pybamm.ScipySolver()
 
     def _set_dict(self, dict, name):
         """
diff --git a/pybamm/solvers/scikits_dae_solver.py b/pybamm/solvers/scikits_dae_solver.py
index c0ba707cd..9b9496dd1 100644
--- a/pybamm/solvers/scikits_dae_solver.py
+++ b/pybamm/solvers/scikits_dae_solver.py
@@ -17,6 +17,10 @@ if scikits_odes_spec is not None:
         scikits_odes_spec.loader.exec_module(scikits_odes)
         from scikits.odes.sundials import ida
 
+        jac_class = ida.IDA_JacRhsFunction
+else:
+    jac_class = object
+
 
 class ScikitsDaeSolver(pybamm.DaeSolver):
     """Solve a discretised model, using scikits.odes.
@@ -99,7 +103,7 @@ class ScikitsDaeSolver(pybamm.DaeSolver):
         return sol.values.t, np.transpose(sol.values.y)
 
 
-class JacobianFunctionIDA(ida.IDA_JacRhsFunction):
+class JacobianFunctionIDA(jac_class):
     def set_jacobian(self, mass_matrix, jacobian):
         """
         Sets the user supplied mass matrix and Jacobian function for the DAE model.
diff --git a/pybamm/solvers/scikits_ode_solver.py b/pybamm/solvers/scikits_ode_solver.py
index 2728d2562..e4ffac8e1 100644
--- a/pybamm/solvers/scikits_ode_solver.py
+++ b/pybamm/solvers/scikits_ode_solver.py
@@ -17,6 +17,10 @@ if scikits_odes_spec is not None:
         scikits_odes_spec.loader.exec_module(scikits_odes)
         from scikits.odes.sundials import cvode
 
+        jac_class = cvode.CV_JacRhsFunction
+else:
+    jac_class = object
+
 
 class ScikitsOdeSolver(pybamm.OdeSolver):
     """Solve a discretised model, using scikits.odes.
@@ -95,7 +99,7 @@ class ScikitsOdeSolver(pybamm.OdeSolver):
         return sol.values.t, np.transpose(sol.values.y)
 
 
-class JacobianFunctionCV(cvode.CV_JacRhsFunction):
+class JacobianFunctionCV(jac_class):
     def set_jacobian(self, jacobian):
         """
         Sets the user supplied Jacobian function for the ODE model.

Tests fail when scikits not installed
**Describe the bug**
All tests fail when scikits not installed, e.g.
```
======================================================================
ERROR: test_discretisations.test_discretisation (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: test_discretisations.test_discretisation
Traceback (most recent call last):
  File "/usr/lib/python3.5/unittest/loader.py", line 428, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib/python3.5/unittest/loader.py", line 369, in _get_module_from_name
    __import__(name)
  File "/home/ivan/workspace/PyBaMM/tests/unit/test_discretisations/test_discretisation.py", line 4, in <module>
    import pybamm
  File "/home/ivan/workspace/PyBaMM/pybamm/__init__.py", line 174, in <module>
    from .solvers.scikits_dae_solver import ScikitsDaeSolver
  File "/home/ivan/workspace/PyBaMM/pybamm/solvers/scikits_dae_solver.py", line 102, in <module>
    class JacobianFunctionIDA(ida.IDA_JacRhsFunction):
NameError: name 'ida' is not defined
```


diff --git a/tests/unit/test_models/test_lead_acid/test_newman_tiedemann.py b/tests/unit/test_models/test_lead_acid/test_newman_tiedemann.py
index 6981e0049..d0df184a5 100644
--- a/tests/unit/test_models/test_lead_acid/test_newman_tiedemann.py
+++ b/tests/unit/test_models/test_lead_acid/test_newman_tiedemann.py
@@ -4,12 +4,14 @@
 from __future__ import absolute_import, division
 from __future__ import print_function, unicode_literals
 import pybamm
+from pybamm.solvers.scikits_ode_solver import scikits_odes_spec
 import tests
 
 import unittest
 import numpy as np
 
 
+@unittest.skipIf(scikits_odes_spec is None, "scikits.odes not installed")
 class TestLeadAcidNewmanTiedemann(unittest.TestCase):
     def test_basic_processing(self):
         model = pybamm.lead_acid.NewmanTiedemann()
diff --git a/tests/unit/test_models/test_lithium_ion/test_lithium_ion_dfn.py b/tests/unit/test_models/test_lithium_ion/test_lithium_ion_dfn.py
index 24fd18740..a51917da6 100644
--- a/tests/unit/test_models/test_lithium_ion/test_lithium_ion_dfn.py
+++ b/tests/unit/test_models/test_lithium_ion/test_lithium_ion_dfn.py
@@ -4,12 +4,14 @@
 from __future__ import absolute_import, division
 from __future__ import print_function, unicode_literals
 import pybamm
+from pybamm.solvers.scikits_ode_solver import scikits_odes_spec
 import tests
 
 import numpy as np
 import unittest
 
 
+@unittest.skipIf(scikits_odes_spec is None, "scikits.odes not installed")
 class TestDFN(unittest.TestCase):
     def test_basic_processing(self):
         model = pybamm.lithium_ion.DFN()
diff --git a/tests/unit/test_models/test_submodels/test_electrode.py b/tests/unit/test_models/test_submodels/test_electrode.py
index 2f2f2088b..4ddfcac0d 100644
--- a/tests/unit/test_models/test_submodels/test_electrode.py
+++ b/tests/unit/test_models/test_submodels/test_electrode.py
@@ -4,6 +4,7 @@
 from __future__ import absolute_import, division
 from __future__ import print_function, unicode_literals
 import pybamm
+from pybamm.solvers.scikits_ode_solver import scikits_odes_spec
 import tests
 import numpy as np
 import numbers
@@ -11,6 +12,7 @@ import numbers
 import unittest
 
 
+@unittest.skipIf(scikits_odes_spec is None, "scikits.odes not installed")
 class TestOhm(unittest.TestCase):
     def test_basic_processing(self):
         # Parameters
diff --git a/tests/unit/test_models/test_submodels/test_electrolyte_current.py b/tests/unit/test_models/test_submodels/test_electrolyte_current.py
index 62048966b..84d256c5b 100644
--- a/tests/unit/test_models/test_submodels/test_electrolyte_current.py
+++ b/tests/unit/test_models/test_submodels/test_electrolyte_current.py
@@ -4,6 +4,7 @@
 from __future__ import absolute_import, division
 from __future__ import print_function, unicode_literals
 import pybamm
+from pybamm.solvers.scikits_ode_solver import scikits_odes_spec
 import tests
 import numbers
 import numpy as np
@@ -11,6 +12,7 @@ import numpy as np
 import unittest
 
 
+@unittest.skipIf(scikits_odes_spec is None, "scikits.odes not installed")
 class TestMacInnesStefanMaxwell(unittest.TestCase):
     def test_basic_processing(self):
         # Parameters

pip install -e .[dev,docs]
parse_log_pytest
requirements.txt
pytest flake8
apt-get update apt-get install -y gfortran gcc libopenblas-dev liblapack-dev graphviz
3.6
requirements/base.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
alabaster==0.7.13
anyio==3.6.2
anytree==2.8.0
argon2-cffi==21.3.0
argon2-cffi-bindings==21.2.0
async-generator==1.10
attrs==22.2.0
autograd==1.6.2
Babel==2.11.0
backcall==0.2.0
bleach==4.1.0
certifi==2021.5.30
cffi==1.15.1
charset-normalizer==2.0.12
comm==0.1.4
contextvars==2.4
cycler==0.11.0
dataclasses==0.8
decorator==5.1.1
defusedxml==0.7.1
docutils==0.17.1
entrypoints==0.4
flake8==5.0.4
future==1.0.0
guzzle-sphinx-theme==0.7.11
idna==3.10
imagesize==1.4.1
immutables==0.19
importlib-metadata==4.2.0
iniconfig==1.1.1
ipykernel==5.5.6
ipython==7.16.3
ipython-genutils==0.2.0
ipywidgets==7.8.5
jedi==0.17.2
Jinja2==3.0.3
json5==0.9.16
jsonschema==3.2.0
jupyter==1.1.1
jupyter-client==7.1.2
jupyter-console==6.4.3
jupyter-core==4.9.2
jupyter-server==1.13.1
jupyterlab==3.2.9
jupyterlab-pygments==0.1.2
jupyterlab-server==2.10.3
jupyterlab_widgets==1.1.11
kiwisolver==1.3.1
MarkupSafe==2.0.1
matplotlib==3.3.4
mccabe==0.7.0
mistune==0.8.4
nbclassic==0.3.5
nbclient==0.5.9
nbconvert==6.0.7
nbformat==5.1.3
nest-asyncio==1.6.0
notebook==6.4.10
numpy==1.19.5
packaging==21.3
pandas==1.1.5
pandocfilters==1.5.1
parso==0.7.1
pexpect==4.9.0
pickleshare==0.7.5
Pillow==8.4.0
pluggy==1.0.0
prometheus-client==0.17.1
prompt-toolkit==3.0.36
ptyprocess==0.7.0
py==1.11.0
-e git+https://github.com/pybamm-team/PyBaMM.git@925337782627408e7644e807d59f6f3ec584850e#egg=pybamm
pycodestyle==2.9.1
pycparser==2.21
pyflakes==2.5.0
Pygments==2.14.0
pyparsing==3.1.4
pyrsistent==0.18.0
pytest==7.0.1
python-dateutil==2.9.0.post0
pytz==2025.2
pyzmq==25.1.2
requests==2.27.1
scipy==1.5.4
Send2Trash==1.8.3
six==1.17.0
sniffio==1.2.0
snowballstemmer==2.2.0
Sphinx==4.3.2
sphinxcontrib-applehelp==1.0.2
sphinxcontrib-devhelp==1.0.2
sphinxcontrib-htmlhelp==2.0.0
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==1.0.3
sphinxcontrib-serializinghtml==1.1.5
terminado==0.12.1
testpath==0.6.0
tomli==1.2.3
tornado==6.1
traitlets==4.3.3
typing_extensions==4.1.1
urllib3==1.26.20
wcwidth==0.2.13
webencodings==0.5.1
websocket-client==1.3.1
widgetsnbextension==3.6.10
zipp==3.6.0

name: PyBaMM
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - alabaster==0.7.13
      - anyio==3.6.2
      - anytree==2.8.0
      - argon2-cffi==21.3.0
      - argon2-cffi-bindings==21.2.0
      - async-generator==1.10
      - attrs==22.2.0
      - autograd==1.6.2
      - babel==2.11.0
      - backcall==0.2.0
      - bleach==4.1.0
      - cffi==1.15.1
      - charset-normalizer==2.0.12
      - comm==0.1.4
      - contextvars==2.4
      - cycler==0.11.0
      - dataclasses==0.8
      - decorator==5.1.1
      - defusedxml==0.7.1
      - docutils==0.17.1
      - entrypoints==0.4
      - flake8==5.0.4
      - future==1.0.0
      - guzzle-sphinx-theme==0.7.11
      - idna==3.10
      - imagesize==1.4.1
      - immutables==0.19
      - importlib-metadata==4.2.0
      - iniconfig==1.1.1
      - ipykernel==5.5.6
      - ipython==7.16.3
      - ipython-genutils==0.2.0
      - ipywidgets==7.8.5
      - jedi==0.17.2
      - jinja2==3.0.3
      - json5==0.9.16
      - jsonschema==3.2.0
      - jupyter==1.1.1
      - jupyter-client==7.1.2
      - jupyter-console==6.4.3
      - jupyter-core==4.9.2
      - jupyter-server==1.13.1
      - jupyterlab==3.2.9
      - jupyterlab-pygments==0.1.2
      - jupyterlab-server==2.10.3
      - jupyterlab-widgets==1.1.11
      - kiwisolver==1.3.1
      - markupsafe==2.0.1
      - matplotlib==3.3.4
      - mccabe==0.7.0
      - mistune==0.8.4
      - nbclassic==0.3.5
      - nbclient==0.5.9
      - nbconvert==6.0.7
      - nbformat==5.1.3
      - nest-asyncio==1.6.0
      - notebook==6.4.10
      - numpy==1.19.5
      - packaging==21.3
      - pandas==1.1.5
      - pandocfilters==1.5.1
      - parso==0.7.1
      - pexpect==4.9.0
      - pickleshare==0.7.5
      - pillow==8.4.0
      - pluggy==1.0.0
      - prometheus-client==0.17.1
      - prompt-toolkit==3.0.36
      - ptyprocess==0.7.0
      - py==1.11.0
      - pycodestyle==2.9.1
      - pycparser==2.21
      - pyflakes==2.5.0
      - pygments==2.14.0
      - pyparsing==3.1.4
      - pyrsistent==0.18.0
      - pytest==7.0.1
      - python-dateutil==2.9.0.post0
      - pytz==2025.2
      - pyzmq==25.1.2
      - requests==2.27.1
      - scipy==1.5.4
      - send2trash==1.8.3
      - six==1.17.0
      - sniffio==1.2.0
      - snowballstemmer==2.2.0
      - sphinx==4.3.2
      - sphinxcontrib-applehelp==1.0.2
      - sphinxcontrib-devhelp==1.0.2
      - sphinxcontrib-htmlhelp==2.0.0
      - sphinxcontrib-jsmath==1.0.1
      - sphinxcontrib-qthelp==1.0.3
      - sphinxcontrib-serializinghtml==1.1.5
      - terminado==0.12.1
      - testpath==0.6.0
      - tomli==1.2.3
      - tornado==6.1
      - traitlets==4.3.3
      - typing-extensions==4.1.1
      - urllib3==1.26.20
      - wcwidth==0.2.13
      - webencodings==0.5.1
      - websocket-client==1.3.1
      - widgetsnbextension==3.6.10
      - zipp==3.6.0
prefix: /opt/conda/envs/PyBaMM

tests/unit/test_models/test_submodels/test_electrode.py::TestExplicitOhm::test_explicit_combined_ohm tests/unit/test_models/test_submodels/test_electrode.py::TestExplicitOhm::test_explicit_leading_order_ohm tests/unit/test_models/test_submodels/test_electrolyte_current.py::TestFirstOrderPotential::test_basic_processing tests/unit/test_models/test_submodels/test_electrolyte_current.py::TestExplicitStefanMaxwell::test_explicit_combined_stefan_maxwell tests/unit/test_models/test_submodels/test_electrolyte_current.py::TestExplicitStefanMaxwell::test_explicit_leading_order_stefan_maxwell
pybamm/__init__.py pybamm/solvers/scikits_ode_solver.py README.md pybamm/models/base_models.py pybamm/solvers/scikits_dae_solver.py
pybamm/__init__.py pybamm/solvers/scikits_ode_solver.py README.md pybamm/models/base_models.py pybamm/solvers/scikits_dae_solver.py