diff --git a/src/LoRa_APRS_iGate.cpp b/src/LoRa_APRS_iGate.cpp
index 7ca0c20..031cb10 100644
--- a/src/LoRa_APRS_iGate.cpp
+++ b/src/LoRa_APRS_iGate.cpp
@@ -47,10 +47,12 @@ WiFi_AP         *currentWiFi            = &Config.wifiAPs[myWiFiAPIndex];
 
 bool            isUpdatingOTA           = false;
 uint32_t        lastBatteryCheck        = 0;
-String          batteryVoltage;
+String          batteryVoltage; // ????
 bool            backUpDigiMode          = false;
 bool            modemLoggedToAPRSIS     = false;
 
+bool            shouldSleep             = false;
+
 std::vector<ReceivedPacket> receivedPackets;
 
 String firstLine, secondLine, thirdLine, fourthLine, fifthLine, sixthLine, seventhLine;
@@ -94,7 +96,7 @@ void setup() {
                 if (lastBeacon == 0 || time - lastBeacon >= Config.beacon.interval * 60) {
                     Serial.println("Sending beacon");
                     String comment = Config.beacon.comment;
-                    if (Config.battery.sendBatteryVoltage) comment += " Batt=" + String(BATTERY_Utils::checkBattery(),2) + "V";
+                    if (Config.battery.sendBatteryVoltage) comment += " Batt=" + String(BATTERY_Utils::checkInternalVoltage(),2) + "V";
                     if (Config.battery.externalVoltageMeasurement) comment += " Ext=" + String(BATTERY_Utils::checkExternalVoltage(),2) + "V";
                     STATION_Utils::addToOutputPacketBuffer(GPS_Utils::getiGateLoRaBeaconPacket() + comment);                
                     lastBeacon = time;
@@ -183,4 +185,5 @@ void loop() {
 
     show_display(firstLine, secondLine, thirdLine, fourthLine, fifthLine, sixthLine, seventhLine, 0);
     Utils::checkRebootTime();
+    Utils::checkSleepByLowBatteryVoltage();
 }
\ No newline at end of file
diff --git a/src/battery_utils.cpp b/src/battery_utils.cpp
index 6f44c5e..0ceebf1 100644
--- a/src/battery_utils.cpp
+++ b/src/battery_utils.cpp
@@ -21,7 +21,7 @@ namespace BATTERY_Utils {
         return (voltage - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
     }
 
-    float checkBattery() { 
+    float checkInternalVoltage() { 
         int sample;
         int sampleSum = 0;
         #ifdef ADC_CTRL
@@ -70,7 +70,7 @@ namespace BATTERY_Utils {
         }
 
         float voltage = ((((sampleSum/100)* adcReadingTransformation) + readingCorrection) * ((R1+R2)/R2)) - multiplyCorrection;
-
+        
         return voltage; // raw voltage without mapping
 
         // return mapVoltage(voltage, 5.05, 6.32, 4.5, 5.5); // mapped voltage
@@ -80,7 +80,7 @@ namespace BATTERY_Utils {
         if (lastBatteryCheck == 0 || millis() - lastBatteryCheck >= 15 * 60 * 1000) {
             lastBatteryCheck = millis();
 
-            float voltage = checkBattery();
+            float voltage = checkInternalVoltage();
             
             if (voltage < Config.lowVoltageCutOff) {
                 ESP.deepSleep(1800000000); // 30 min sleep (60s = 60e6)
diff --git a/src/battery_utils.h b/src/battery_utils.h
index fd50532..697a471 100644
--- a/src/battery_utils.h
+++ b/src/battery_utils.h
@@ -6,9 +6,9 @@
 
 namespace BATTERY_Utils {
 
-    float checkBattery();
-    float checkExternalVoltage();
-    void checkIfShouldSleep();
+    float   checkInternalVoltage();
+    float   checkExternalVoltage();
+    void    checkIfShouldSleep();
 
 }
 
diff --git a/src/utils.cpp b/src/utils.cpp
index 4dba2ad..a5e3487 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -32,6 +32,7 @@ extern String               distance;
 extern bool                 WiFiConnected;
 extern int                  wxModuleType;
 extern bool                 backUpDigiMode;
+extern bool                 shouldSleep;
 
 bool        statusAfterBoot     = true;
 bool        beaconUpdate        = true;
@@ -123,18 +124,27 @@ namespace Utils {
 
             #ifdef BATTERY_PIN
                 if (Config.battery.sendInternalVoltage) {
-                    String batteryInfo = "Batt=" + String(BATTERY_Utils::checkBattery(),2) + "V";
-                    beaconPacket += " " + batteryInfo;
-                    secondaryBeaconPacket += " " + batteryInfo;
-                    sixthLine = "     ( " + batteryInfo + ")";
+                    float internalVoltage       = BATTERY_Utils::checkInternalVoltage();
+                    String internalVoltageInfo  = "Batt=" + String(internalVoltage,2) + "V";
+                    beaconPacket += " " + internalVoltageInfo;
+                    secondaryBeaconPacket += " " + internalVoltageInfo;
+                    sixthLine = "    ( " + internalVoltageInfo + ")";
                 }
             #endif
 
-            if (Config.battery.sendExternalVoltage) {
-                String externalVoltage = String(BATTERY_Utils::checkExternalVoltage(),2) + "V";
-                beaconPacket += " Ext=" + externalVoltage;
-                secondaryBeaconPacket += " Ext=" + externalVoltage;
-                sixthLine = "    (Ext V=" + externalVoltage;
+            if (Config.battery.sendExternalVoltage || Config.battery.monitorExternalVoltage) {
+                float externalVoltage       = BATTERY_Utils::checkExternalVoltage();
+                String externalVoltageInfo  = String(externalVoltage,2) + "V";
+                if (Config.battery.sendExternalVoltage) {
+                    beaconPacket += " Ext=" + externalVoltageInfo;
+                    secondaryBeaconPacket += " Ext=" + externalVoltageInfo;
+                    sixthLine = "    (Ext V=" + externalVoltageInfo + ")";
+                }
+                if (Config.battery.monitorExternalVoltage && externalVoltage <= Config.battery.externalSleepVoltage) {
+                    beaconPacket += " **ExtBatWarning:SLEEP**";
+                    secondaryBeaconPacket += " **ExtBatWarning:SLEEP**";
+                    shouldSleep = true;
+                }
             }
 
             if (Config.aprs_is.active && Config.beacon.sendViaAPRSIS && !backUpDigiMode) {
@@ -262,4 +272,12 @@ namespace Utils {
         }
     }
 
+    void checkSleepByLowBatteryVoltage() {
+        if (shouldSleep) {
+            // dormir
+            shouldSleep = false;
+            Serial.println("Durmiendo");
+        }
+    }
+
 }
\ No newline at end of file
diff --git a/src/utils.h b/src/utils.h
index 17dc7ed..b8491f6 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -25,6 +25,7 @@ namespace Utils {
     void println(const String& text);
     void checkRebootMode();
     void checkRebootTime();
+    void checkSleepByLowBatteryVoltage();
 
 }