diff --git a/lib/obp60task/OBPSensorTask.cpp b/lib/obp60task/OBPSensorTask.cpp
index 99071ab7..cd488ab8 100644
--- a/lib/obp60task/OBPSensorTask.cpp
+++ b/lib/obp60task/OBPSensorTask.cpp
@@ -88,8 +88,16 @@ void sensorTask(void *param){
     double voffset = (api->getConfig()->getConfigItem(api->getConfig()->vOffset,true)->asString()).toFloat();
     double vslope = (api->getConfig()->getConfigItem(api->getConfig()->vSlope,true)->asString()).toFloat();
     if(String(powsensor1) == "off"){
-        sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.17) * 20;   // Vin = 1/20
+        #ifdef VOLTAGE_SENSOR
+        sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.53) * 2;   // Vin = 1/2 for OBP40
+        #else
+        sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.17) * 20;   // Vin = 1/20 for OBP60    
+        #endif
         sensors.batteryVoltage = sensors.batteryVoltage * vslope + voffset; // Calibration
+        #ifdef LIPO_ACCU_1200
+        sensors.BatteryChargeStatus = 0;    // Set to discharging
+        sensors.batteryLevelLiPo = 0;       // Level 0...100%
+        #endif
         sensors.batteryCurrent = 0;
         sensors.batteryPower = 0;
         // Fill average arrays with start values
@@ -459,8 +467,29 @@ void sensorTask(void *param){
         // Send supply voltage value all 1s
         if(millis() > starttime5 + 1000 && String(powsensor1) == "off"){
             starttime5 = millis();
-            sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.17) * 20;   // Vin = 1/20
+            #ifdef VOLTAGE_SENSOR
+            sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.53) * 2;   // Vin = 1/2 for OBP40
+            #else
+            sensors.batteryVoltage = (float(analogRead(OBP_ANALOG0)) * 3.3 / 4096 + 0.17) * 20;   // Vin = 1/20 for OBP60    
+            #endif
             sensors.batteryVoltage = sensors.batteryVoltage * vslope + voffset; // Calibration
+            #ifdef LIPO_ACCU_1200
+            if(sensors.batteryVoltage > 4.1){
+                sensors.BatteryChargeStatus = 1;    // Charging active
+            }
+            else{
+                sensors.BatteryChargeStatus = 0;    // Discharging
+            }
+            // Polynomfit for LiPo capacity calculation for 3,7V LiPo accus, 0...100%
+            sensors.batteryLevelLiPo = sensors.batteryVoltage * sensors.batteryVoltage * 174.9513 + sensors.batteryVoltage * 1147,7686 + 1868.5120;
+            // Limiter
+            if(sensors.batteryLevelLiPo > 100){
+                sensors.batteryLevelLiPo = 100;
+            }
+            if(sensors.batteryLevelLiPo < 0){
+                sensors.batteryLevelLiPo = 0;
+            }
+            #endif
             // Save new data in average array
             batV.reading(int(sensors.batteryVoltage * 100));
             // Calculate the average values for different time lines from integer values
diff --git a/lib/obp60task/Pagedata.h b/lib/obp60task/Pagedata.h
index b385b5cf..d511aee1 100644
--- a/lib/obp60task/Pagedata.h
+++ b/lib/obp60task/Pagedata.h
@@ -31,6 +31,8 @@ typedef struct{
   double batteryVoltage300 = 0; // Sliding average over 300 values
   double batteryCurrent300 = 0;
   double batteryPower300 = 0;
+  double batteryLevelLiPo = 0;  // Battery level for OBP40 LiPo accu
+  int BatteryChargeStatus = 0;  // LiPo charge status: 0 = discharge, 1 = loading activ
   double solarVoltage = 0;
   double solarCurrent = 0;
   double solarPower = 0;
diff --git a/lib/obp60task/platformio.ini b/lib/obp60task/platformio.ini
index da78f39d..662032a1 100644
--- a/lib/obp60task/platformio.ini
+++ b/lib/obp60task/platformio.ini
@@ -2,7 +2,9 @@
 #if you want a pio run to only build
 #your special environments you can set this here
 #by uncommenting the next line
-default_envs = obp60_s3
+default_envs =
+    obp60_s3
+    obp40_s3
 
 [env:obp60_s3]
 platform = espressif32@6.8.1
@@ -91,6 +93,8 @@ build_flags=
     -D DISABLE_DIAGNOSTIC_OUTPUT    #Disable diagnostic output for GxEPD2 lib
     -D BOARD_OBP40S3                #Board OBP40 V1.0 with ESP32S3 SKU:DIE07300S (CrowPanel 4.2)
     -D DISPLAY_GDEY042T81           #new E-Ink display from Waveshare, R10 2.2 ohm
+    -D LIPO_ACCU_1200               #Hardware extension, LiPo accu 3,7V 1200mAh
+    -D VOLTAGE_SENSOR               #Hardware extension, LiPo voltage sensor with two resistors 
     ${env.build_flags}
 upload_port = /dev/ttyUSB0          #OBP40 download via external USB/Serail converter
 upload_protocol = esptool           #firmware upload via USB OTG seriell, by first upload need to set the ESP32-S3 in the upload mode with shortcut GND to Pin27