diff --git a/MainCode/adalm1000_logger.py b/MainCode/adalm1000_logger.py
index b31f375..7094fd9 100644
--- a/MainCode/adalm1000_logger.py
+++ b/MainCode/adalm1000_logger.py
@@ -912,11 +912,17 @@ class BatteryTester(QMainWindow):
         
         # Button style
         button_style = f"""
-            {base_style}
-            font-weight: bold;
-            padding: 4px 8px;
-            border-radius: 4px;
-            min-height: 28px;
+            QPushButton {{
+                {base_style}
+                font-weight: bold;
+                padding: 4px 8px;
+                border-radius: 4px;
+                min-height: 28px;
+                background-color: {self.accent_color};
+            }}
+            QPushButton:checked {{
+                background-color: {self.warning_color};
+            }}
         """
         
         # Single toggle button (Start/Stop)
@@ -939,10 +945,9 @@ class BatteryTester(QMainWindow):
         # Record button for Live mode
         self.record_button = QPushButton("● Start Recording")
         self.record_button.setCheckable(True)
-        self.record_button.setStyleSheet(button_style + f"""
-            background-color: {self.success_color};
-            min-width: 140px;
-        """)
+        self.record_button.setStyleSheet(button_style.replace(
+            self.accent_color, self.success_color
+        ))
         self.record_button.clicked.connect(self.toggle_global_recording)
         button_layout.addWidget(self.record_button)
         self.record_button.hide()
@@ -1154,7 +1159,7 @@ class BatteryTester(QMainWindow):
         self.ax.set_ylim(min_voltage, max_voltage)
         
         # Voltage plot
-        self.line_voltage, = self.ax.plot([], [], color='#00BFFF', label='Voltage (V)', linewidth=2)
+        self.line_voltage, = self.ax.plot([0], [0], color='#00BFFF', label='Voltage (V)', linewidth=2)
         self.ax.set_ylabel("Voltage (V)", color='#00BFFF')
         self.ax.tick_params(axis='y', labelcolor='#00BFFF')
 
@@ -1165,7 +1170,7 @@ class BatteryTester(QMainWindow):
         max_current = test_current * 1.5
         self.ax2.set_ylim(-max_current - current_padding, max_current + current_padding)
         
-        self.line_current, = self.ax2.plot([], [], 'r-', label='Current (A)', linewidth=2)
+        self.line_current, = self.ax2.plot([0], [0], 'r-', label='Current (A)', linewidth=2)
         self.ax2.set_ylabel("Current (A)", color='r')
         self.ax2.tick_params(axis='y', labelcolor='r')
 
@@ -1449,12 +1454,17 @@ class BatteryTester(QMainWindow):
         dev.current_data.append(current)
         
         # Calculate metrics
+        power = voltage * abs(current)  # Always define power
         if len(dev.time_data) > 1:
             delta_t = dev.time_data[-1] - dev.time_data[-2]
-            power = voltage * abs(current)
             dev.capacity_ah += abs(current) * delta_t / 3600  # Ah
             dev.energy += power * delta_t / 3600  # Wh
         
+        # Update display buffers
+        dev.display_time_data.append(current_time)
+        dev.display_voltage_data.append(voltage)
+        dev.display_current_data.append(current)
+        
         # Update UI for active device
         self.voltage_label.setText(f"{voltage:.4f}")
         self.current_label.setText(f"{abs(current):.4f}")
@@ -2514,8 +2524,8 @@ class BatteryTester(QMainWindow):
                 return
                 
             # Create local copies of data safely
+            dev = self.active_device
             with self.plot_mutex:
-                dev = self.active_device
                 if not dev.display_time_data:
                     return