diff --git a/README.md b/README.md
index cb386a1d..bfc231a5 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,9 @@
 python-OBD
 ==========
 
+**Forked version**
+- Added voltage gathering even if car is off
+
 A python module for handling realtime sensor data from OBD-II vehicle
 ports. Works with ELM327 OBD-II adapters, and is fit for the Raspberry
 Pi.
diff --git a/obd/elm327.py b/obd/elm327.py
index 79e6abff..07bc8c97 100644
--- a/obd/elm327.py
+++ b/obd/elm327.py
@@ -120,6 +120,9 @@ def __init__(self, portname, baudrate, protocol, timeout,
         self.__low_power = False
         self.timeout = timeout
 
+        # custom
+        self.___voltage = ''
+
         # ------------- open port -------------
         try:
             self.__port = serial.serial_for_url(portname,
@@ -177,6 +180,8 @@ def __init__(self, portname, baudrate, protocol, timeout,
         # -------------------------- AT RV (read volt) ------------------------
         if check_voltage:
             r = self.__send(b"AT RV")
+            # save voltage to instance (useful even if car turned off)
+            self.___voltage = r
             if not r or len(r) != 1 or r[0] == '':
                 self.__error("No answer from 'AT RV'")
                 return
@@ -565,3 +570,8 @@ def __read(self):
         lines = [s.strip() for s in re.split("[\r\n]", string) if bool(s)]
 
         return lines
+
+    @property
+    def voltage(self):
+        """ return the voltage saved on init """
+        return self.___voltage
\ No newline at end of file
diff --git a/obd/obd.py b/obd/obd.py
index 5bd29e60..3957e119 100644
--- a/obd/obd.py
+++ b/obd/obd.py
@@ -59,6 +59,9 @@ def __init__(self, portstr=None, baudrate=None, protocol=None, fast=True,
         self.__last_header = ECU_HEADER.ENGINE  # for comparing with the previously used header
         self.__frame_counts = {}  # keeps track of the number of return frames for each command
 
+        # custom vars
+        self.___voltage = ''
+
         logger.info("======================= python-OBD (v%s) =======================" % __version__)
         self.__connect(portstr, baudrate, protocol,
                        check_voltage, start_low_power)  # initialize by connecting and loading sensors
@@ -98,6 +101,7 @@ def __connect(self, portstr, baudrate, protocol, check_voltage,
         if self.interface.status() == OBDStatus.NOT_CONNECTED:
             # the ELM327 class will report its own errors
             self.close()
+        else: self.___voltage = self.interface.voltage
 
     def __load_commands(self):
         """
@@ -313,3 +317,8 @@ def __build_command_string(self, cmd):
             cmd_string = b""
 
         return cmd_string
+
+    @property
+    def voltage(self):
+        """ get the voltage gathered from interface on init """
+        return self.___voltage