diff --git a/README.md b/README.md
index dc9bae6c..e8ad0b69 100644
--- a/README.md
+++ b/README.md
@@ -252,16 +252,17 @@ These cheap devices often handle SD-cards up to 32GB, not bigger ones. They can
 
 The software included here writes data in a file named PAXCOUNT.xx, where xx can range from 00 to 99. The software starts with 00, checks to see if such a file already exists and if yes it will continue with the next number (up to 99 - in this case it will return no sd-card). So an existing file will not be overwritten.
 
-The data is written to the card and after 3 write-operations the data is flushed to the disk. So maybe the last 3 minutes of data get lost when you disconnect the PAXCOUNTER from power.
+The data is written to the card and after 3 write-operations the data is flushed to the disk. Thus, up to the last 3 records of data will get lost when the PAXCOUNTER looses power.
 
 And finally: this is the data written to the disk:
 
-	timestamp, wifi, ble
+	timestamp,wifi,ble[,voltage]
 	2022-01-28T19:36:35Z,17,48
 	2022-01-28T19:37:35Z,21,52
 	2022-01-28T19:38:35Z,14,49
 	
 Format of the data is CSV, timestamp is ISO8601, which can easily imported into LibreOffice, Excel, Influx, etc.
+Voltage is logged, if the device has a battery voltage sensor (to be configure in board hal file).
 
 If you want to change this please look into src/sdcard.cpp and include/sdcard.h.
 
diff --git a/include/sdcard.h b/include/sdcard.h
index 8d20ced5..4d04f3ab 100644
--- a/include/sdcard.h
+++ b/include/sdcard.h
@@ -55,10 +55,10 @@
 #endif
 
 #define SDCARD_FILE_NAME "/paxcount.%02d"
-#define SDCARD_FILE_HEADER "timestamp, wifi, ble"
+#define SDCARD_FILE_HEADER "timestamp,wifi,ble"
 
-#if (COUNT_ENS)
-#define SDCARD_FILE_HEADER_CWA ",cwa"
+#if (defined BAT_MEASURE_ADC || defined HAS_PMU)
+#define SDCARD_FILE_HEADER_VOLTAGE ",voltage"
 #endif
 
 bool sdcard_init(void);
diff --git a/src/sdcard.cpp b/src/sdcard.cpp
index 783cf657..396f5257 100644
--- a/src/sdcard.cpp
+++ b/src/sdcard.cpp
@@ -40,7 +40,7 @@ bool sdcard_init() {
 }
 
 void sdcardWriteData(uint16_t noWifi, uint16_t noBle,
-                     __attribute__((unused)) uint16_t noBleCWA) {
+                     __attribute__((unused)) uint16_t voltage) {
   static int counterWrites = 0;
   char tempBuffer[20 + 1];
   time_t t = time(NULL);
@@ -59,8 +59,8 @@ void sdcardWriteData(uint16_t noWifi, uint16_t noBle,
   fileSDCard.print(tempBuffer);
   snprintf(tempBuffer, sizeof(tempBuffer), ",%d,%d", noWifi, noBle);
   fileSDCard.print(tempBuffer);
-#if (COUNT_ENS)
-  snprintf(tempBuffer, sizeof(tempBuffer), ",%d", noBleCWA);
+#if (defined BAT_MEASURE_ADC || defined HAS_PMU)
+  snprintf(tempBuffer, sizeof(tempBuffer), ",%d", voltage);
   fileSDCard.print(tempBuffer);
 #endif
 #if (HAS_SDS011)
@@ -105,8 +105,8 @@ void createFile(void) {
       if (fileSDCard) {
         ESP_LOGD(TAG, "SD: file opened: <%s>", bufferFilename);
         fileSDCard.print(SDCARD_FILE_HEADER);
-#if (COUNT_ENS)
-        fileSDCard.print(SDCARD_FILE_HEADER_CWA); // for Corona-data (CWA)
+#if (defined BAT_MEASURE_ADC || defined HAS_PMU)
+        fileSDCard.print(SDCARD_FILE_HEADER_VOLTAGE); // for battery level data
 #endif
 #if (HAS_SDS011)
         fileSDCard.print(SDCARD_FILE_HEADER_SDS011);
diff --git a/src/senddata.cpp b/src/senddata.cpp
index fce1d325..bc9ee702 100644
--- a/src/senddata.cpp
+++ b/src/senddata.cpp
@@ -120,9 +120,9 @@ void sendData() {
 #endif
 #if (HAS_SDCARD)
         sdcardWriteData(libpax_macs_wifi, libpax_macs_ble
-#if (COUNT_ENS)
+#if (defined BAT_MEASURE_ADC || defined HAS_PMU)
                         ,
-                        cwa_report()
+                        read_voltage()
 #endif
         );
 #endif // HAS_SDCARD