diff --git a/include/charger.h b/include/charger.h
index f4e138e..872dc06 100644
--- a/include/charger.h
+++ b/include/charger.h
@@ -9,4 +9,5 @@ void CalcTotals();
 void DisableAll();
 void EvseRead();
 bool CheckStartCondition();
+bool CheckVoltage();
 #endif
diff --git a/libopeninv/libopeninv.a b/libopeninv/libopeninv.a
index c947dd3..ba7384a 100644
Binary files a/libopeninv/libopeninv.a and b/libopeninv/libopeninv.a differ
diff --git a/src/charger.cpp b/src/charger.cpp
index 0261ee3..4cf9359 100644
--- a/src/charger.cpp
+++ b/src/charger.cpp
@@ -54,6 +54,23 @@ bool CheckStartCondition()
          (!IsEvseInput() && Param::GetBool(Param::enable));
 }
 
+bool CheckVoltage()
+{
+   static int timeout = 0;
+
+   if (Param::Get(Param::udc) > Param::Get(Param::udclim))
+   {
+      timeout++;
+   }
+   else
+   {
+      timeout = 0;
+   }
+
+   return timeout > 10;
+}
+
+
 bool CheckTimeout()
 {
    uint32_t now = rtc_get_counter_val();
diff --git a/src/main.cpp b/src/main.cpp
index 8d37c57..755c775 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -48,23 +48,6 @@ static Can* can;
 static PiController dcCurController;
 uint32_t startTime;
 
-
-static bool CheckVoltage()
-{
-   static int timeout = 0;
-
-   if (Param::Get(Param::udc) > Param::Get(Param::udclim))
-   {
-      timeout++;
-   }
-   else
-   {
-      timeout = 0;
-   }
-
-   return timeout > 10;
-}
-
 static bool CheckChargerFaults()
 {
    const int acPresentThresh = 70;
diff --git a/test/test.c b/test/test.c
index 4737b31..5bdf44c 100644
--- a/test/test.c
+++ b/test/test.c
@@ -23,6 +23,7 @@ int main() {
       (TestCase){"test_check_timeout", test_check_timeout},
       (TestCase){"test_evse_read", test_evse_read},
       (TestCase){"test_check_start_condition", test_check_start_condition},
+      (TestCase){"test_check_voltage", test_check_voltage},
       // Example:
       //(TestCase){"Your tests name", function_name_without_brackets}
       //...
diff --git a/test/test.out b/test/test.out
index 109cd2a..ff6cca7 100755
Binary files a/test/test.out and b/test/test.out differ
diff --git a/test/test_logic.h b/test/test_logic.h
index 7193552..9a9f28b 100644
--- a/test/test_logic.h
+++ b/test/test_logic.h
@@ -129,3 +129,19 @@ void test_check_start_condition()
   res = CheckStartCondition();
   assert(!res);
 }
+
+void test_check_voltage(){
+  bool res;
+  Param::SetInt(Param::udc, 400);
+  Param::SetInt(Param::udclim, 390);
+
+  // tolerate up to ten one off spikes
+  res = CheckVoltage();
+  assert(!res);
+
+  // drop out if received more than ten 
+  for(int i =0; i < 15;i++){
+    res = CheckVoltage();
+  }
+  assert(res);
+}