Index: firmware/App/Drivers/Battery.c
===================================================================
diff -u -rd2d9f19fd458bad756c2468ea10fceb0c11d4200 -r54ee9a1d1778fd6f33735082a5e4e58facce5292
--- firmware/App/Drivers/Battery.c	(.../Battery.c)	(revision d2d9f19fd458bad756c2468ea10fceb0c11d4200)
+++ firmware/App/Drivers/Battery.c	(.../Battery.c)	(revision 54ee9a1d1778fd6f33735082a5e4e58facce5292)
@@ -51,8 +51,12 @@
 // ********** private function prototypes **********
 
 static void setupI2CDriver( void );
+static BOOL startCommTx( U32 slaveAddr );
 static BOOL waitForTxReady( void );
-static BOOL getBatteryData( U32 slaveAddr, U08 command, U16 * dataPtr );
+static BOOL waitForRxReady( void );
+static BOOL waitForAccessReady( void );
+static void generateStopCondition( void );
+static BOOL getBatteryData( U08 command, U16 * dataPtr );
 
 /*********************************************************************//**
  * @brief
@@ -84,33 +88,31 @@
         {
             hasBatteryChargerStatus = TRUE;
 
-            if ( TRUE == getBatteryData( BATTERY_CHARGER_SLAVE_ADDRESS, BATTERY_CHARGER_STATUS_CMD, &batteryStatus ) )
+            if ( TRUE == startCommTx( BATTERY_CHARGER_SLAVE_ADDRESS ) )
             {
-                if ( ( batteryStatus & BATTERY_CHARGER_STATUS_AC_PRESENT_MASK ) == 0 )
+                if ( TRUE == getBatteryData( BATTERY_CHARGER_STATUS_CMD, &batteryStatus ) )
                 {
-                    if ( ++lostACPowerPersistentCount > AC_POWER_LOST_PERSISTENT_COUNT )
+                    if ( ( batteryStatus & BATTERY_CHARGER_STATUS_AC_PRESENT_MASK ) == 0 )
                     {
-                        SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_AC_POWER_LOST, batteryStatus );
+                        if ( ++lostACPowerPersistentCount > AC_POWER_LOST_PERSISTENT_COUNT )
+                        {
+                            SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_AC_POWER_LOST, batteryStatus );
+                        }
                     }
+                    else
+                    {
+                        lostACPowerPersistentCount = 0;
+                    }
                 }
-                else
-                {
-                    lostACPowerPersistentCount = 0;
-                }
             }
-            else
-            {
-                // Reset i2c bus if cannot communicate with battery charger
-                setupI2CDriver();
-            }
         }
         else
         {
             hasBatteryChargerStatus = FALSE;
 
-            if ( FALSE == getBatteryData( BATTERY_PACK_SLAVE_ADDRESS, BATTERY_PACK_REL_STATE_OF_CHARGE_CMD, &batteryRelStateOfCharge_pct ) )
+            if ( TRUE == startCommTx( BATTERY_PACK_SLAVE_ADDRESS ) )
             {
-                setupI2CDriver();
+                getBatteryData( BATTERY_PACK_REL_STATE_OF_CHARGE_CMD, &batteryRelStateOfCharge_pct );
             }
         }
 #endif
@@ -147,11 +149,54 @@
 
 /*********************************************************************//**
  * @brief
+ * The startComm function starts i2c communication and verifies slave devices ack.
+ * @details Inputs: none
+ * @details Outputs: starts i2c comm in master transmit mode
+ * @param slaveAddr slave device address
+ * @return none
+ *************************************************************************/
+static BOOL startCommTx( U32 slaveAddr )
+{
+    BOOL result = FALSE;
+
+    i2cSetSlaveAdd( i2cREG1, slaveAddr );
+
+    if ( FALSE == i2cIsBusBusy( i2cREG1 ) )
+    {
+        i2cSetDirection( i2cREG1, I2C_TRANSMITTER );
+        i2cSetMode( i2cREG1, I2C_MASTER );
+        i2cSetStart( i2cREG1 );
+
+        if ( TRUE == waitForAccessReady() )
+        {
+            if ( 0 == ( i2cREG1->STR & ( (U32)I2C_NACK | (U32)I2C_AL ) ) )
+            {
+                result = TRUE;
+            }
+            else
+            {
+                generateStopCondition();
+            }
+        }
+
+    }
+
+    if ( FALSE == result )
+    {
+        // Reset i2c bus if cannot communicate with battery slave devices
+        setupI2CDriver();
+    }
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
  * The waitForTxReady function checks for transmit ready status from i2c
  * driver with a timeout.
  * @details Inputs: none
  * @details Outputs: checked i2c transmit ready status
- * @return TRUE if timeout, otherwise FALSE
+ * @return TRUE if i2c driver ready to transmit data, otherwise FALSE
  *************************************************************************/
 static BOOL waitForTxReady( void )
 {
@@ -163,7 +208,7 @@
         timeout = didTimeout( startTime, BATTERY_COMM_TIME_OUT_MS );
     }
 
-    return timeout;
+    return ( TRUE == timeout ? FALSE : TRUE );
 }
 
 /*********************************************************************//**
@@ -172,7 +217,7 @@
  * driver with a timeout.
  * @details Inputs: none
  * @details Outputs: checked i2c receive ready status
- * @return TRUE if timeout, otherwise FALSE
+ * @return TRUE if i2c driver ready to receive data, otherwise FALSE
  *************************************************************************/
 static BOOL waitForRxReady( void )
 {
@@ -184,53 +229,84 @@
         timeout = didTimeout( startTime, BATTERY_COMM_TIME_OUT_MS );
     }
 
-    return timeout;
+    return ( TRUE == timeout ? FALSE : TRUE );
 }
 
 /*********************************************************************//**
  * @brief
+ * The waitForAccessReady function checks if i2c registers are ready to be accessed.
+ * @details Inputs: none
+ * @details Outputs: checked i2c registers access ready status
+ * @return TRUE if i2c driver registers are ready to be accessed, otherwise FALSE
+ *************************************************************************/
+static BOOL waitForAccessReady( void )
+{
+    U32 const startTime = getMSTimerCount();
+    BOOL timeout = FALSE;
+
+    while ( ( 0 == ( i2cREG1->STR & (U32)I2C_ARDY ) ) && ( FALSE == timeout ) )
+    {
+        timeout = didTimeout( startTime, BATTERY_COMM_TIME_OUT_MS );
+    }
+
+    return ( TRUE == timeout ? FALSE : TRUE );
+}
+
+/*********************************************************************//**
+ * @brief
+ * The generateStopCondition function generates a i2c stop condition and
+ * waits until the stop condition is detected or timed out.
+ * @details Inputs: none
+ * @details Outputs: generated i2c stop condition
+ * @return none
+ *************************************************************************/
+static void generateStopCondition( void )
+{
+    U32 const startTime = getMSTimerCount();
+    BOOL timeout = FALSE;
+
+    i2cSetStop( i2cREG1 );
+    while ( ( 0 == i2cIsStopDetected( i2cREG1 ) ) && ( FALSE == timeout ) )
+    {
+        timeout = didTimeout( startTime, BATTERY_COMM_TIME_OUT_MS );
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The getBatteryStatus function send command to smart battery charger controller
  * interface to get battery status.
  * @details Inputs: none
  * @details Outputs: get the battery data based on given command
- * @param slaveAddr slave device address
  * @param command command to send to the slave device
+ * @param dataPtr data pointer to store command response data
  * @return TRUE if received battery status, otherwise FALSE
  *************************************************************************/
-static BOOL getBatteryData( U32 slaveAddr, U08 command, U16 * dataPtr )
+static BOOL getBatteryData( U08 command, U16 * dataPtr )
 {
     BOOL result = FALSE;
 
-    i2cSetSlaveAdd( i2cREG1, slaveAddr );
+    if ( TRUE == waitForTxReady() )
+    {
+        i2cSendByte( i2cREG1, command );
+    }
 
-    if ( FALSE == i2cIsBusBusy( i2cREG1 ) )
+    // Wait until command has been transmitted before start receiving command response
+    if ( TRUE == waitForTxReady() )
     {
-        i2cSetMode( i2cREG1, I2C_MASTER );
-        i2cSetDirection( i2cREG1, I2C_TRANSMITTER );
+        i2cSetDirection( i2cREG1, I2C_RECEIVER );
         i2cSetStart( i2cREG1 );
 
-        if ( FALSE == waitForTxReady() )
+        if ( TRUE == waitForRxReady() )
         {
-            i2cSendByte( i2cREG1, command );
-        }
+            // Due to the double buffer, the master must generate the stop condition after the (message size - 1)th data
+            i2cSetStop( i2cREG1 );
+            *dataPtr = i2cReceiveByte( i2cREG1);
 
-        // Wait until command has been transmitted before start receiving command response
-        if ( FALSE == waitForTxReady() )
-        {
-            i2cSetDirection( i2cREG1, I2C_RECEIVER );
-            i2cSetStart( i2cREG1 );
-
-            if ( FALSE == waitForRxReady() )
+            if ( TRUE == waitForRxReady() )
             {
-                // Due to the double buffer, the master must generate the stop condition after the (message size - 1)th data
-                i2cSetStop( i2cREG1 );
-                *dataPtr = i2cReceiveByte( i2cREG1);
-
-                if ( FALSE == waitForRxReady() )
-                {
-                    *dataPtr = ( *dataPtr | ( i2cReceiveByte( i2cREG1) << 8 ) );
-                    result = TRUE;
-                }
+                *dataPtr = ( *dataPtr | ( i2cReceiveByte( i2cREG1) << 8 ) );
+                result = TRUE;
             }
         }
     }