add test for low capacity check

src/rfbzero/experiment.py

@@ -167,7 +167,7 @@ class CycleStatus(str, Enum):
     VOLTAGE_LIMIT_REACHED = 'voltage limits reached'
     CURRENT_CUTOFF_REACHED = 'current cutoffs reached'
     LIMITING_CURRENT_REACHED = 'current has exceeded the limiting currents for the cell concentrations'
-    LOW_CAPACITY = 'capacity is less than 1 coulomb'
+    LOW_CAPACITY = 'capacity is less than 1% of initial CLS capacity'
     TIME_DURATION_REACHED = 'time duration reached'
 
 

tests/test_experiment.py

@@ -3,13 +3,13 @@
 
 from rfbzero.experiment import ConstantCurrent, ConstantCurrentConstantVoltage, ConstantVoltage
 from rfbzero.redox_flow_cell import ZeroDModel
-from rfbzero.degradation import ChemicalDegradation, AutoOxidation, AutoReduction, MultiDegradationMechanism#, Dimerization
+from rfbzero.degradation import ChemicalDegradation, AutoOxidation, AutoReduction, \
+    MultiDegradationMechanism  # , Dimerization
 from rfbzero.crossover import Crossover
 
 
 class TestCyclingProtocolResults:
 
-
     @pytest.mark.skip(reason="not implemented yet")
     def test_state_of_charge(self):
         r_cls = 0.2
@@ -87,20 +87,20 @@ def test_cv1(self):
                                   species='red',
                                   )
 
-        protocol = ConstantCurrentConstantVoltage(
+        protocol = ConstantVoltage(
             voltage_limit_charge=0.2,  # volts
             voltage_limit_discharge=-0.2,  # volts
             current_cutoff_charge=0.005,  # amps
             current_cutoff_discharge=-0.005,  # amps
-            current=1.5,  # amps
         )
 
         # putting it all together
         all_results = protocol.run(cell_model=cell,
                                    degradation=deg,
                                    duration=1000,  # cycle time to simulate (s)
                                    )
-        expected = [4.809806770737516, 9.616034709809167, 9.61843069453628, 9.611898460659235, 9.611890636955804]
+
+        expected = [4.809806770737513, 9.616034709809167, 9.61843069453628, 9.611898460659237, 9.611890636955808]
         vals = all_results.half_cycle_capacity[:5]
         assert np.isclose(vals, expected).all()
 
@@ -191,3 +191,84 @@ def test_cccv_symmetric_cell(self):
         assert np.isclose(vals, expected).all()
 
 
+class TestAsymmetricCurrents:
+    def test_cc(self):
+        deg = ChemicalDegradation(rate_order=2, rate_constant=3e-5, species='red')
+
+        cell_1 = ZeroDModel(cls_volume=0.005,  # L
+                            ncls_volume=0.03,  # L
+                            cls_start_c_ox=0.01,  # M
+                            cls_start_c_red=0.01,  # M
+                            ncls_start_c_ox=0.01,  # M
+                            ncls_start_c_red=0.01,  # M
+                            ocv_50_soc=0.0,  # V
+                            resistance=0.8,  # ohms
+                            k_0_cls=1e-3,  # cm/s
+                            k_0_ncls=1e-3,  # cm/s
+                            )
+        protocol_1 = ConstantCurrent(voltage_limit_charge=0.2,  # V
+                                     voltage_limit_discharge=-0.2,  # V
+                                     current=0.05,  # A
+                                     )
+        all_results_1 = protocol_1.run(cell_model=cell_1,
+                                       duration=1000,  # cycle time to simulate (s)
+                                       degradation=deg,
+                                       )
+        vals_1 = all_results_1.half_cycle_capacity[:5]
+
+        #
+        cell_2 = ZeroDModel(cls_volume=0.005,  # L
+                            ncls_volume=0.03,  # L
+                            cls_start_c_ox=0.01,  # M
+                            cls_start_c_red=0.01,  # M
+                            ncls_start_c_ox=0.01,  # M
+                            ncls_start_c_red=0.01,  # M
+                            ocv_50_soc=0.0,  # V
+                            resistance=0.8,  # ohms
+                            k_0_cls=1e-3,  # cm/s
+                            k_0_ncls=1e-3,  # cm/s
+                            )
+        protocol_2 = ConstantCurrent(voltage_limit_charge=0.2,  # V
+                                     voltage_limit_discharge=-0.2,  # V
+                                     current_charge=0.05,  # A
+                                     current_discharge=-0.05,  # A
+                                     )
+        all_results_2 = protocol_2.run(cell_model=cell_2,
+                                       duration=1000,  # cycle time to simulate (s)
+                                       degradation=deg,
+                                       )
+        vals_2 = all_results_2.half_cycle_capacity[:5]
+
+        assert vals_1 == vals_2
+
+
+class TestLowCapacity:
+
+    def test_cc(self, capsys):
+        deg = ChemicalDegradation(rate_order=2, rate_constant=10, species='red')
+
+        cell = ZeroDModel(cls_volume=0.005,  # L
+                          ncls_volume=0.03,  # L
+                          cls_start_c_ox=0.01,  # M
+                          cls_start_c_red=0.01,  # M
+                          ncls_start_c_ox=0.01,  # M
+                          ncls_start_c_red=0.01,  # M
+                          ocv_50_soc=0.0,  # V
+                          resistance=0.8,  # ohms
+                          k_0_cls=1e-3,  # cm/s
+                          k_0_ncls=1e-3,  # cm/s
+                          )
+        protocol = ConstantCurrent(voltage_limit_charge=0.2,  # V
+                                   voltage_limit_discharge=-0.2,  # V
+                                   current=0.05,  # A
+                                   )
+        all_results = protocol.run(cell_model=cell,
+                                   duration=1000,  # cycle time to simulate (s)
+                                   degradation=deg,
+                                   )
+
+        warn_out = "capacity is less than 1% of initial CLS capacity."
+        captured = capsys.readouterr()
+
+        cyclestatus = captured.out.strip().rsplit('time steps: ', 1)[1]
+        assert cyclestatus == warn_out