diff --git a/Duplicati/Library/Utility/Duplicati.Library.Utility.csproj b/Duplicati/Library/Utility/Duplicati.Library.Utility.csproj
index c32d167dd..3c9c4d271 100644
--- a/Duplicati/Library/Utility/Duplicati.Library.Utility.csproj
+++ b/Duplicati/Library/Utility/Duplicati.Library.Utility.csproj
@@ -82,6 +82,7 @@
     <Compile Include="Power\DefaultPowerSupplyState.cs" />
     <Compile Include="Power\LinuxPowerSupplyState.cs" />
     <Compile Include="Power\WindowsPowerSupplyState.cs" />
+    <Compile Include="Power\MacOSPowerSupplyState.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="app.config" />
diff --git a/Duplicati/Library/Utility/Power/MacOSPowerSupplyState.cs b/Duplicati/Library/Utility/Power/MacOSPowerSupplyState.cs
new file mode 100644
index 000000000..7bec0bd8a
--- /dev/null
+++ b/Duplicati/Library/Utility/Power/MacOSPowerSupplyState.cs
@@ -0,0 +1,108 @@
+//  Copyright (C) 2017, The Duplicati Team
+//  http://www.duplicati.com, info@duplicati.com
+//
+//  This library is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as
+//  published by the Free Software Foundation; either version 2.1 of the
+//  License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful, but
+//  WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+using System;
+using System.Linq;
+
+namespace Duplicati.Library.Utility.Power
+{
+    public class MacOSPowerSupplyState : IPowerSupplyState
+    {
+        public PowerSupply.Source GetSource()
+        {
+            var src = GetSourcePmset();
+            if (src == PowerSupply.Source.Unknown)
+                src = GetSourceIoreg();
+
+            return src;
+        }
+
+        /// <summary>
+        /// Gets the current power source using `pmset`
+        /// </summary>
+        /// <returns>The power source according to pmset.</returns>
+        private PowerSupply.Source GetSourcePmset()
+        {
+            try
+            {
+                var psi = new System.Diagnostics.ProcessStartInfo("pmset", "-g batt");
+                psi.RedirectStandardOutput = true;
+                psi.UseShellExecute = false;
+
+                var pi = System.Diagnostics.Process.Start(psi);
+                pi.WaitForExit(1000);
+                if (pi.HasExited)
+                {
+                    var pmout = pi.StandardOutput.ReadToEnd().Trim();
+                    if (pmout.IndexOf("'AC Power'", StringComparison.OrdinalIgnoreCase) >= 0)
+                        return PowerSupply.Source.AC;
+                    if (pmout.IndexOf("'Battery Power'", StringComparison.OrdinalIgnoreCase) >= 0)
+                        return PowerSupply.Source.Battery;
+                }
+                else
+                    pi.Kill();
+
+                return PowerSupply.Source.Unknown;
+            }
+            catch
+            {
+                return PowerSupply.Source.Unknown;
+            }
+        }
+
+        /// <summary>
+        /// Gets the current power source using `ioreg`
+        /// </summary>
+        /// <returns>The power source according to ioreg.</returns>
+        private PowerSupply.Source GetSourceIoreg()
+        {
+            try
+            {
+                var psi = new System.Diagnostics.ProcessStartInfo("ioreg", "-n AppleSmartBattery -r");
+                psi.RedirectStandardOutput = true;
+                psi.UseShellExecute = false;
+
+                var pi = System.Diagnostics.Process.Start(psi);
+                pi.WaitForExit(1000);
+                if (pi.HasExited)
+                {
+                    // Find:
+                    // "ExternalConnected" = Yes
+                    var ioreg = pi.StandardOutput.ReadToEnd()
+                                  .Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries)
+                                  .Select(x => x.Trim())
+                                  .Where(x => x.StartsWith("\"ExternalConnected\"", StringComparison.OrdinalIgnoreCase))
+                                  .Select(x => x.Split(new char[] { '=' }, 2).LastOrDefault())
+                                  .FirstOrDefault();
+
+                    if (string.Equals(ioreg, "No", StringComparison.OrdinalIgnoreCase))
+                        return PowerSupply.Source.Battery;
+
+                    if (string.Equals(ioreg, "Yes", StringComparison.OrdinalIgnoreCase))
+                        return PowerSupply.Source.AC;
+                }
+                else
+                    pi.Kill();
+
+                return PowerSupply.Source.Unknown;
+            }
+            catch
+            {
+                return PowerSupply.Source.Unknown;
+            }
+        }
+    }
+}
diff --git a/Duplicati/Library/Utility/Power/PowerSupply.cs b/Duplicati/Library/Utility/Power/PowerSupply.cs
index ff5deadb6..09b653fca 100644
--- a/Duplicati/Library/Utility/Power/PowerSupply.cs
+++ b/Duplicati/Library/Utility/Power/PowerSupply.cs
@@ -33,7 +33,7 @@ namespace Duplicati.Library.Utility.Power
             // Since IsClientLinux returns true when on Mac OS X, we need to check IsClientOSX first.
             if (Utility.IsClientOSX)
             {
-                state = new DefaultPowerSupplyState();
+                state = new MacOSPowerSupplyState();
             }
             else if (Utility.IsClientLinux)
             {