Enable tlp and powertop for battery saving
diff --git a/modules/battery.nix b/modules/battery.nix
new file mode 100644
index 0000000..381d956
--- /dev/null
+++ b/modules/battery.nix
@@ -0,0 +1,12 @@
+{pkgs, ...}: {
+  config = {
+    services.tlp.enable = true;
+
+    powerManagement.powertop.enable = true;
+
+    environment = {
+      systemPackages = [pkgs.powertop];
+      persistence."/nix/persist".directories = ["/var/cache/powertop"];
+    };
+  };
+}