diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58bff31..bfe380e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@
            - Improved start-up checks for permissions
            - Improved system re-start after changing settings (but still not perfect!)
            - Disabled the CNN algorithm by default as it is causing some false alarms (Issue #170)
-           - Added watch signal strength trend graph to main activity
+           - Added watch signal strength history graph and watch battery hisory graph to main activity
     V4.2.5 - Set BLE device time if the characteristic is available.
     V4.2.4 - Added checks and a FAULT condition for Bluetooth errors in Bluetooth Data Source
     V4.2.3 - Uses 3d accelerometer data to calculate magnitude if vector magnitude is not sent from data source.
diff --git a/app/src/main/java/uk/org/openseizuredetector/FragmentBatt.java b/app/src/main/java/uk/org/openseizuredetector/FragmentBatt.java
index 4bb0432..4a40974 100644
--- a/app/src/main/java/uk/org/openseizuredetector/FragmentBatt.java
+++ b/app/src/main/java/uk/org/openseizuredetector/FragmentBatt.java
@@ -64,7 +64,7 @@ public class FragmentBatt extends FragmentOsdBaseClass {
     @Override
     public void onResume() {
         super.onResume();
-        mLineChart = mRootView.findViewById(R.id.lineChart);
+        mLineChart = mRootView.findViewById(R.id.battLineChart);
         mLineChart.getLegend().setEnabled(false);
         XAxis xAxis = mLineChart.getXAxis();
         xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
@@ -76,8 +76,8 @@ public class FragmentBatt extends FragmentOsdBaseClass {
         xAxis.setTextColor(Color.WHITE);
 
         YAxis yAxis = mLineChart.getAxisLeft();
-        yAxis.setAxisMinValue(40f);
-        yAxis.setAxisMaxValue(240f);
+        yAxis.setAxisMinValue(0f);
+        yAxis.setAxisMaxValue(100f);
         yAxis.setDrawGridLines(true);
         yAxis.setDrawLabels(true);
         yAxis.setTextColor(Color.WHITE);
@@ -111,6 +111,7 @@ public class FragmentBatt extends FragmentOsdBaseClass {
             double watchBattArr[] = mConnection.mSdServer.mSdData.watchBattBuff.getVals();   // This gives us a simple vector of hr values to plot.
             int nPhoneBattArr = mConnection.mSdServer.mSdData.phoneBattBuff.getNumVals();
             double phoneBattArr[] = mConnection.mSdServer.mSdData.phoneBattBuff.getVals();
+            Log.i(TAG,"updateUi() - nWatchBattArr="+nWatchBattArr+", nPhoneBattArr="+nPhoneBattArr);
             if (Objects.nonNull(mConnection.mSdServer.mSdData.watchBattBuff) && nWatchBattArr > 0) {
                 Log.v(TAG, "hrWatchBattBuff.getNumVals=" + nWatchBattArr);
                 lineDataSet.clear();
diff --git a/app/src/main/java/uk/org/openseizuredetector/MainActivity2.java b/app/src/main/java/uk/org/openseizuredetector/MainActivity2.java
index 8275e98..a423152 100644
--- a/app/src/main/java/uk/org/openseizuredetector/MainActivity2.java
+++ b/app/src/main/java/uk/org/openseizuredetector/MainActivity2.java
@@ -320,8 +320,8 @@ public class MainActivity2 extends AppCompatActivity {
                     return new FragmentSystem();
                 case 3:
                     return new FragmentWatchSig();
-                //case 4:
-                //    return new FragmentBatt();
+                case 4:
+                    return new FragmentBatt();
                 //case 4:
                 //    return new FragmentDataSharing();
 
@@ -333,7 +333,7 @@ public class MainActivity2 extends AppCompatActivity {
 
         @Override
         public int getItemCount() {
-            return 4;
+            return 5;
         }
     }
 
diff --git a/app/src/main/java/uk/org/openseizuredetector/SdDataSource.java b/app/src/main/java/uk/org/openseizuredetector/SdDataSource.java
index 4e48e75..b05c029 100644
--- a/app/src/main/java/uk/org/openseizuredetector/SdDataSource.java
+++ b/app/src/main/java/uk/org/openseizuredetector/SdDataSource.java
@@ -390,7 +390,6 @@ public abstract class SdDataSource {
                 mSamplePeriod = (short) dataObject.getInt("analysisPeriod");
                 mSampleFreq = (short) dataObject.getInt("sampleFreq");
                 mSdData.batteryPc = (short) dataObject.getInt("battery");
-                mSdData.watchBattBuff.add(mSdData.batteryPc);
 
                 Log.v(TAG, "updateFromJSON - mSamplePeriod=" + mSamplePeriod + " mSampleFreq=" + mSampleFreq);
                 mUtil.writeToSysLogFile("SDDataSource.updateFromJSON - Settings Received");
@@ -475,6 +474,7 @@ public abstract class SdDataSource {
         // Update phone battery level - it is done here so it is called for all data sources.
         mSdData.phoneBatteryPc = getPhoneBatteryLevel();
         mSdData.phoneBattBuff.add(mSdData.phoneBatteryPc);
+        mSdData.watchBattBuff.add(mSdData.batteryPc);
         try {
             // FIXME - Use specified sampleFreq, not this hard coded one
             mSampleFreq = 25;
diff --git a/app/src/main/res/layout/fragment_batt.xml b/app/src/main/res/layout/fragment_batt.xml
index 4a6e11e..92afc40 100644
--- a/app/src/main/res/layout/fragment_batt.xml
+++ b/app/src/main/res/layout/fragment_batt.xml
@@ -19,7 +19,7 @@
 
 
         <com.github.mikephil.charting.charts.LineChart
-            android:id="@+id/lineChart"
+            android:id="@+id/battLineChart"
             android:layout_width="fill_parent"
             android:layout_height="fill_parent">