diff --git a/GpsTracker/GpsTracker.ino b/GpsTracker/GpsTracker.ino
index 75589bc..64c8a8e 100644
--- a/GpsTracker/GpsTracker.ino
+++ b/GpsTracker/GpsTracker.ino
@@ -14,6 +14,8 @@ void setup() {
 	rtc::setup();
 	hardware::sdcard::setup();
 	hardware::sim808::setup();
+
+	positions::setup();
 }
 
 void loop() {
diff --git a/GpsTracker/Positions.cpp b/GpsTracker/Positions.cpp
index 85b2030..115ef22 100644
--- a/GpsTracker/Positions.cpp
+++ b/GpsTracker/Positions.cpp
@@ -29,7 +29,9 @@ namespace positions {
 		//TODO : enable/disable based on config
 		_backupLength = 1;
 		_backups = new backup::PositionsBackup*[_backupLength];
+		
 		_backups[0] = new backup::sd::SdPositionsBackup();
+		_backups[0]->setup();
 	}
 
 	bool acquire(PositionEntryMetadata &metadata) {
diff --git a/GpsTracker/SdCard.cpp b/GpsTracker/SdCard.cpp
index 33243ad..d33185a 100644
--- a/GpsTracker/SdCard.cpp
+++ b/GpsTracker/SdCard.cpp
@@ -4,9 +4,10 @@ namespace hardware {
 	namespace sdcard {
 
 		SdFat filesystem;
+		bool available = false;
 
 		void setup() {
-			filesystem.begin(SD_SS);
+			available = filesystem.begin(SD_SS);
 		}
 
 	}
diff --git a/GpsTracker/SdCard.h b/GpsTracker/SdCard.h
index 9596915..fde853a 100644
--- a/GpsTracker/SdCard.h
+++ b/GpsTracker/SdCard.h
@@ -7,6 +7,7 @@ namespace hardware {
 	namespace sdcard {
 
 		extern SdFat filesystem;
+		extern bool available;
 
 		void setup();
 	}
diff --git a/GpsTracker/SdPositionsBackup.cpp b/GpsTracker/SdPositionsBackup.cpp
index 1ede67d..c971a20 100644
--- a/GpsTracker/SdPositionsBackup.cpp
+++ b/GpsTracker/SdPositionsBackup.cpp
@@ -5,6 +5,9 @@
 #include "Config.h"
 #include "SdFat.h"
 #include "Positions.h"
+#include "Debug.h"
+
+#define LOGGER_NAME "Positions::backup::sd"
 
 namespace positions {
 	namespace backup {
@@ -20,38 +23,92 @@ namespace positions {
 						positions::count(sdConfig.lastSavedEntry) > sdConfig.saveThreshold;
 				}
 
-				void appendPositions(const File &file, SdPositionConfig_t &sdConfig) {
+				void getPositionsFileName(uint16_t fileIndex, char *buffer) {
+					sprintf(buffer, POSITIONS_FILENAME, fileIndex);
+				}
+
+				void ensurePositionsFolder() {
+					char positionsFolder[] = POSITIONS_FOLDER;
+
+					hardware::sdcard::filesystem.chdir();
+					if (!hardware::sdcard::filesystem.exists(positionsFolder)) {
+						hardware::sdcard::filesystem.mkdir(positionsFolder, true);
+					}
+
+					hardware::sdcard::filesystem.chdir(positionsFolder);
+				}
+
+				void selectFile(SdPositionConfig_t &sdConfig, File &file) {
+					char positionFileName[POSITIONS_FILENAME_LENGTH];
+
+					if (sdConfig.fileRecords >= sdConfig.maxRecordsPerFile) {
+						if (file.isOpen()) {
+							file.close();
+							config::backup::sd::set(sdConfig);
+						}
+
+						sdConfig.fileIndex++;
+						sdConfig.filePosition = 0;
+						sdConfig.fileRecords = 0;
+					}
+
+					if (!file.isOpen()) {
+						ensurePositionsFolder();
+						getPositionsFileName(sdConfig.fileIndex, positionFileName);
+						file.open(positionFileName, O_RDWR | O_CREAT);
+					}
+				}
+
+				void appendPosition(File &file, SdPositionConfig_t &sdConfig, PositionEntry &entry) {
+					VERBOSE("appendPosition");
+
+					const char fieldTerminator = ',';
+
+					file.printField(entry.metadata.batteryLevel, fieldTerminator);
+					file.printField(entry.metadata.batteryVoltage, fieldTerminator);
+					file.printField(entry.metadata.temperature, fieldTerminator);
+					file.printField(entry.metadata.timeToFix, fieldTerminator);
+					file.printField(static_cast<uint8_t>(entry.metadata.status), fieldTerminator);
+					file.println(entry.position);
+
+					sdConfig.filePosition = file.position();
+				}
+
+				void appendPositions(SdPositionConfig_t &sdConfig) {
+					VERBOSE("appendPositions");
+
 					uint16_t currentEntryIndex = sdConfig.lastSavedEntry + 1;
 					PositionEntry currentEntry;
+					File file;
 
 					hardware::i2c::powerOn();
 					do {
 						if (!positions::get(currentEntryIndex, currentEntry)) break;
-
-						sdConfig.filePosition = file.position();
-					} while (true);
+						selectFile(sdConfig, file);
+						appendPosition(file, sdConfig, currentEntry);
+						sdConfig.lastSavedEntry = currentEntryIndex;
+					} while (positions::moveNext(currentEntryIndex));
 					hardware::i2c::powerOff();
 
+					if (file.isOpen()) file.close();
+					config::backup::sd::set(sdConfig);
 				}
 			}
 
-			void SdPositionsBackup::setup() {
-				config::backup::sd::setup();
-			}
+			void SdPositionsBackup::setup() { }
 
 			void SdPositionsBackup::backup() {
-				SdPositionConfig_t sdConfig;
-
-				if (!details::isBackupNeeded(sdConfig)) return;
+				VERBOSE("backup");
 
-				char *filename;
-				hardware::sdcard::filesystem.chdir("positions");
-				File file = hardware::sdcard::filesystem.open(filename, O_RDWR | O_CREAT);
+				if (!hardware::sdcard::available) {
+					VERBOSE_MSG("backup", "not available");
+					return;
+				}
 
-				file.seek(sdConfig.filePosition);
-				file.find('\n');
+				SdPositionConfig_t sdConfig;
 
-				details::appendPositions(file, sdConfig);
+				if (!details::isBackupNeeded(sdConfig)) return;
+				details::appendPositions(sdConfig);
 			}
 
 		}
diff --git a/GpsTracker/SdPositionsBackup.h b/GpsTracker/SdPositionsBackup.h
index de5f5ac..98ac21e 100644
--- a/GpsTracker/SdPositionsBackup.h
+++ b/GpsTracker/SdPositionsBackup.h
@@ -3,6 +3,11 @@
 #include "PositionsBackup.h"
 #include "RawSdFile.h"
 
+#define POSITIONS_FOLDER	"positions"
+#define POSITIONS_FILENAME	"positions-%05d.csv"
+#define POSITIONS_FILENAME_LENGTH 19
+
+
 using namespace sd;
 
 namespace positions {
diff --git a/GpsTracker/SdPositionsConfig.cpp b/GpsTracker/SdPositionsConfig.cpp
index de40a10..6d50885 100644
--- a/GpsTracker/SdPositionsConfig.cpp
+++ b/GpsTracker/SdPositionsConfig.cpp
@@ -40,8 +40,6 @@ namespace config {
 
 				}
 
-				void setup() { }
-
 				SdPositionConfig_t get() {
 					if (value.seed != POSITIONS_CONFIG_SEED) details::read();
 
@@ -57,7 +55,8 @@ namespace config {
 					VERBOSE("reset");
 					SdPositionConfig_t config = {
 						POSITIONS_CONFIG_SEED,
-						POSITIONS_CONFIG_DeFAULT_SAVE_THRESHOLD,
+						POSITIONS_CONFIG_DEFAULT_SAVE_THRESHOLD,
+						POSITIONS_CONFIG_DEFAULT_MAX_RECORDS_PER_FILE,
 						0xFFFF,
 						0,
 						0,
diff --git a/GpsTracker/SdPositionsConfig.h b/GpsTracker/SdPositionsConfig.h
index 04b78d2..935448e 100644
--- a/GpsTracker/SdPositionsConfig.h
+++ b/GpsTracker/SdPositionsConfig.h
@@ -4,11 +4,13 @@
 
 #define POSITIONS_CONFIG_FILENAME "positions.config"
 #define POSITIONS_CONFIG_SEED 45
-#define POSITIONS_CONFIG_DeFAULT_SAVE_THRESHOLD 10
+#define POSITIONS_CONFIG_DEFAULT_SAVE_THRESHOLD 10
+#define POSITIONS_CONFIG_DEFAULT_MAX_RECORDS_PER_FILE 5
 
 struct SdPositionConfig_t {
 	uint8_t seed;
 	uint8_t saveThreshold;
+	uint8_t maxRecordsPerFile;
 	uint16_t lastSavedEntry;
 	uint16_t fileIndex;
 	uint32_t filePosition;