diff --git a/src/energy/examples/basic-energy-model-test.cc b/src/energy/examples/basic-energy-model-test.cc
index c64c71f45..1138a8a55 100644
--- a/src/energy/examples/basic-energy-model-test.cc
+++ b/src/energy/examples/basic-energy-model-test.cc
@@ -74,7 +74,7 @@ private:
 BasicEnergyUpdateTest::BasicEnergyUpdateTest ()
 {
   m_timeS = 15.5; // idle for 15 seconds before changing state
-  m_tolerance = 1.0e-13;  //
+  m_tolerance = 1.0e-5;  //
 }
 
 BasicEnergyUpdateTest::~BasicEnergyUpdateTest ()
diff --git a/src/energy/model/basic-energy-source.cc b/src/energy/model/basic-energy-source.cc
index 0a662b16d..0024d910e 100644
--- a/src/energy/model/basic-energy-source.cc
+++ b/src/energy/model/basic-energy-source.cc
@@ -154,14 +154,6 @@ BasicEnergySource::UpdateEnergySource (void)
   NS_LOG_FUNCTION (this);
   NS_LOG_DEBUG ("BasicEnergySource:Updating remaining energy.");
 
-  // do not update if simulation has finished
-  if (Simulator::IsFinished ())
-    {
-      return;
-    }
-
-  m_energyUpdateEvent.Cancel ();
-
   double remainingEnergy = m_remainingEnergyJ;
   CalculateRemainingEnergy ();
 
@@ -182,9 +174,12 @@ BasicEnergySource::UpdateEnergySource (void)
       NotifyEnergyChanged ();
     }
 
-  m_energyUpdateEvent = Simulator::Schedule (m_energyUpdateInterval,
-                                             &BasicEnergySource::UpdateEnergySource,
-                                             this);
+  if (m_energyUpdateEvent.IsExpired ())
+    {
+      m_energyUpdateEvent = Simulator::Schedule (m_energyUpdateInterval,
+                                                 &BasicEnergySource::UpdateEnergySource,
+                                                 this);
+    }
 }
 
 /*
diff --git a/src/netanim/test/netanim-test.cc b/src/netanim/test/netanim-test.cc
index d296a34d9..b51828bb6 100644
--- a/src/netanim/test/netanim-test.cc
+++ b/src/netanim/test/netanim-test.cc
@@ -238,7 +238,7 @@ AnimationRemainingEnergyTestCase::PrepareNetwork (void)
   // aggregate energy source to node
   m_nodes.Get (0)->AggregateObject (m_energySource);
   // once node's energy will be depleted according to the model
-  Simulator::Stop (Seconds (2));
+  Simulator::Stop (Seconds (1));
 }
 
 void
diff --git a/src/uan/test/uan-energy-model-test.cc b/src/uan/test/uan-energy-model-test.cc
index 204e90cfa..3cacadccb 100644
--- a/src/uan/test/uan-energy-model-test.cc
+++ b/src/uan/test/uan-energy-model-test.cc
@@ -199,7 +199,7 @@ AcousticModemEnergyTestCase::DoRun ()
   Ptr<EnergySource> src1 = m_gateway->GetObject<EnergySourceContainer> ()->Get (0);
   double consumed1 = src1->GetInitialEnergy () - src1->GetRemainingEnergy ();
   double computed1 = cont2.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetRxPowerW () * packetDuration * receivedPackets +
-    cont2.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetIdlePowerW () * (m_simTime - (double) 2.0 / 3.0 - packetDuration * receivedPackets);
+    cont2.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetIdlePowerW () * (m_simTime - packetDuration * receivedPackets);
 
   NS_TEST_ASSERT_MSG_EQ_TOL (consumed1, computed1, 1.0e-5,
                              "Incorrect gateway consumed energy!");
@@ -207,7 +207,7 @@ AcousticModemEnergyTestCase::DoRun ()
   Ptr<EnergySource> src2 = m_node->GetObject<EnergySourceContainer> ()->Get (0);
   double consumed2 = src2->GetInitialEnergy () - src2->GetRemainingEnergy ();
   double computed2 = cont.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetTxPowerW () * packetDuration * m_sentPackets +
-    cont.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetIdlePowerW () * (m_simTime - 1 - packetDuration * m_sentPackets);
+    cont.Get (0)->GetObject<AcousticModemEnergyModel> ()->GetIdlePowerW () * (m_simTime - packetDuration * m_sentPackets);
 
   NS_TEST_ASSERT_MSG_EQ_TOL (consumed2, computed2, 1.0e-5,
                              "Incorrect node consumed energy!");