diff --git a/notebooks/AGIPD/Characterize_AGIPD_Gain_Darks_NBC.ipynb b/notebooks/AGIPD/Characterize_AGIPD_Gain_Darks_NBC.ipynb
index 47460226ab8813a1cf0adfcd95c6e8559e1fee71..5dc3a6c48990ee9e1ef68ad05dfc3f0bd9014668 100644
--- a/notebooks/AGIPD/Characterize_AGIPD_Gain_Darks_NBC.ipynb
+++ b/notebooks/AGIPD/Characterize_AGIPD_Gain_Darks_NBC.ipynb
@@ -50,7 +50,7 @@
     "db_output = False # output constants to database\n",
     "\n",
     "mem_cells = 0 # number of memory cells used, set to 0 to automatically infer\n",
-    "bias_voltage = 300 # detector bias voltage\n",
+    "bias_voltage = 0 # detector bias voltage\n",
     "gain_setting = 0.1 # the gain setting, use 0.1 to try to auto-determine\n",
     "acq_rate = 0. # the detector acquisition rate, use 0 to try to auto-determine\n",
     "interlaced = False # assume interlaced data format, for data prior to Dec. 2017\n",
@@ -222,7 +222,11 @@
     "h5path = h5path.format(karabo_id, receiver_id)\n",
     "h5path_idx = h5path_idx.format(karabo_id, receiver_id)\n",
     "\n",
-    "bias_voltage = get_bias_voltage(control_names[0], karabo_id_control)\n",
+    "if bias_voltage == 0: \n",
+    "    # Read the bias voltage from files, if recorded.\n",
+    "    # If not available, make use of the historical voltage the detector is running at\n",
+    "    bias_voltage = get_bias_voltage(control_names[0], karabo_id_control)\n",
+    "    bias_voltage = bias_voltage if bias_voltage is not None else 300\n",
     "\n",
     "print(\"Parameters are:\")\n",
     "print(f\"Proposal: {prop}\")\n",