diff --git a/changelog.md b/changelog.md
index e82e829..ff2accb 100644
--- a/changelog.md
+++ b/changelog.md
@@ -3,6 +3,14 @@
 ## Pending
 
 
+### Features
+
+- support unknown/unreachable duration thresholds (actions)
+  - Add optional unknownMinutes thresholds for actions when UPS status remains unknown or unreachable.
+  - Allow shutdown and Proxmox actions to run on configured unknown-state threshold violations.
+  - Expose unknown duration and threshold values to script and webhook actions.
+  - Update CLI and systemd output to configure and display unknown/unreachable thresholds.
+
 ## 2026-05-29 - 5.11.2
 
 ### Fixes
diff --git a/test/test.ts b/test/test.ts
index c48c5fe..0f5e93a 100644
--- a/test/test.ts
+++ b/test/test.ts
@@ -19,6 +19,7 @@ import {
   applyDefaultShutdownDelay,
   buildUpsActionContext,
   decideUpsActionExecution,
+  getUnknownStatusDurationMinutes,
 } from '../ts/action-orchestration.ts';
 import {
   buildShutdownErrorRow,
@@ -43,6 +44,7 @@ import { MigrationV4_2ToV4_3 } from '../ts/migrations/migration-v4.2-to-v4.3.ts'
 import { MigrationV4_3ToV4_4 } from '../ts/migrations/migration-v4.3-to-v4.4.ts';
 import { ActionHandler } from '../ts/cli/action-handler.ts';
 import { ProxmoxAction } from '../ts/actions/proxmox-action.ts';
+import { ShutdownAction } from '../ts/actions/shutdown-action.ts';
 import { renderUpgradeChangelog } from '../ts/upgrade-changelog.ts';
 
 import * as qenv from 'npm:@push.rocks/qenv@^6.0.0';
@@ -302,12 +304,33 @@ Deno.test('buildUpsActionContext: includes previous power status and timestamp',
       batteryCapacity: 42,
       batteryRuntime: 15,
       previousPowerStatus: 'online',
+      unknownDurationMinutes: 0,
       timestamp: 9999,
       triggerReason: 'thresholdViolation',
     },
   );
 });
 
+Deno.test('getUnknownStatusDurationMinutes: tracks unknown and unreachable durations only', () => {
+  assertEquals(
+    getUnknownStatusDurationMinutes({
+      ...createInitialUpsStatus({ id: 'ups-1', name: 'Main UPS' }, 1_000),
+      powerStatus: 'unknown',
+      lastStatusChange: 1_000,
+    }, 181_000),
+    3,
+  );
+
+  assertEquals(
+    getUnknownStatusDurationMinutes({
+      ...createInitialUpsStatus({ id: 'ups-1', name: 'Main UPS' }, 1_000),
+      powerStatus: 'online',
+      lastStatusChange: 1_000,
+    }, 181_000),
+    0,
+  );
+});
+
 Deno.test('decideUpsActionExecution: suppresses actions while paused', () => {
   const decision = decideUpsActionExecution(
     true,
@@ -368,6 +391,7 @@ Deno.test('decideUpsActionExecution: returns executable action plan when actions
       batteryCapacity: 55,
       batteryRuntime: 18,
       previousPowerStatus: 'online',
+      unknownDurationMinutes: 0,
       timestamp: 9999,
       triggerReason: 'powerStatusChange',
     },
@@ -571,6 +595,30 @@ Deno.test('isActionThresholdExceeded: evaluates a single action threshold on bat
   );
 });
 
+Deno.test('isActionThresholdExceeded: evaluates unknown duration threshold separately', () => {
+  assertEquals(
+    isActionThresholdExceeded(
+      { type: 'shutdown', thresholds: { battery: 50, runtime: 20, unknownMinutes: 10 } },
+      'unreachable',
+      100,
+      60,
+      9.9,
+    ),
+    false,
+  );
+
+  assertEquals(
+    isActionThresholdExceeded(
+      { type: 'shutdown', thresholds: { battery: 50, runtime: 20, unknownMinutes: 10 } },
+      'unknown',
+      100,
+      60,
+      10,
+    ),
+    true,
+  );
+});
+
 Deno.test('getActionThresholdStates: returns per-action threshold state array', () => {
   assertEquals(
     getActionThresholdStates('onBattery', 25, 8, [
@@ -582,6 +630,16 @@ Deno.test('getActionThresholdStates: returns per-action threshold state array',
   );
 });
 
+Deno.test('getActionThresholdStates: includes unknown duration thresholds', () => {
+  assertEquals(
+    getActionThresholdStates('unreachable', 100, 60, [
+      { type: 'shutdown', thresholds: { battery: 30, runtime: 10, unknownMinutes: 15 } },
+      { type: 'shutdown', thresholds: { battery: 30, runtime: 10, unknownMinutes: 20 } },
+    ], 15),
+    [true, false],
+  );
+});
+
 Deno.test('getEnteredThresholdIndexes: reports only newly-entered thresholds', () => {
   assertEquals(getEnteredThresholdIndexes(undefined, [false, true, true]), [1, 2]);
   assertEquals(getEnteredThresholdIndexes([false, true, false], [true, true, false]), [0]);
@@ -714,6 +772,30 @@ Deno.test('evaluateGroupActionThreshold: blocks destructive actions when a membe
   assertEquals(evaluation.blockedByUnreachable, true);
 });
 
+Deno.test('evaluateGroupActionThreshold: allows configured unknown duration threshold', () => {
+  const evaluation = evaluateGroupActionThreshold(
+    { type: 'shutdown', thresholds: { battery: 50, runtime: 20, unknownMinutes: 10 } },
+    'nonRedundant',
+    [
+      {
+        ...createInitialUpsStatus({ id: 'ups-1', name: 'UPS 1' }, 1000),
+        powerStatus: 'unreachable' as const,
+        lastStatusChange: 1000,
+        unreachableSince: 1000,
+      },
+      {
+        ...createInitialUpsStatus({ id: 'ups-2', name: 'UPS 2' }, 1000),
+        powerStatus: 'online' as const,
+      },
+    ],
+    601000,
+  );
+
+  assertEquals(evaluation.exceedsThreshold, true);
+  assertEquals(evaluation.blockedByUnreachable, false);
+  assertEquals(evaluation.exceededByUnknownDuration, true);
+});
+
 Deno.test('buildGroupThresholdContextStatus: uses the worst triggering member runtime', () => {
   const status = buildGroupThresholdContextStatus(
     { id: 'group-3', name: 'Group Worst' },
@@ -721,6 +803,7 @@ Deno.test('buildGroupThresholdContextStatus: uses the worst triggering member ru
       {
         exceedsThreshold: true,
         blockedByUnreachable: false,
+        exceededByUnknownDuration: false,
         representativeStatus: {
           ...createInitialUpsStatus({ id: 'ups-1', name: 'UPS 1' }, 1000),
           powerStatus: 'onBattery' as const,
@@ -731,6 +814,7 @@ Deno.test('buildGroupThresholdContextStatus: uses the worst triggering member ru
       {
         exceedsThreshold: true,
         blockedByUnreachable: false,
+        exceededByUnknownDuration: false,
         representativeStatus: {
           ...createInitialUpsStatus({ id: 'ups-2', name: 'UPS 2' }, 1000),
           powerStatus: 'onBattery' as const,
@@ -934,6 +1018,12 @@ class TestProxmoxAction extends ProxmoxAction {
   }
 }
 
+class TestShutdownAction extends ShutdownAction {
+  public testShouldExecute(context: IActionContext): boolean {
+    return this.shouldExecute(context);
+  }
+}
+
 function createMockContext(overrides: Partial<IActionContext> = {}): IActionContext {
   return {
     upsId: 'test-ups',
@@ -942,6 +1032,7 @@ function createMockContext(overrides: Partial<IActionContext> = {}): IActionCont
     batteryCapacity: 100,
     batteryRuntime: 60,
     previousPowerStatus: 'online',
+    unknownDurationMinutes: 0,
     timestamp: Date.now(),
     triggerReason: 'powerStatusChange',
     ...overrides,
@@ -1120,6 +1211,58 @@ Deno.test('ProxmoxAction.shouldExecute: skips thresholds unless UPS is confirmed
   );
 });
 
+Deno.test('ProxmoxAction.shouldExecute: allows configured unknown duration threshold', () => {
+  const action = new TestProxmoxAction({
+    type: 'proxmox',
+    triggerMode: 'onlyThresholds',
+    thresholds: { battery: 50, runtime: 20, unknownMinutes: 10 },
+  });
+
+  assertEquals(
+    action.testShouldExecute(createMockContext({
+      powerStatus: 'unreachable',
+      triggerReason: 'thresholdViolation',
+      unknownDurationMinutes: 9.9,
+    })),
+    false,
+  );
+
+  assertEquals(
+    action.testShouldExecute(createMockContext({
+      powerStatus: 'unreachable',
+      triggerReason: 'thresholdViolation',
+      unknownDurationMinutes: 10,
+    })),
+    true,
+  );
+});
+
+Deno.test('ShutdownAction.shouldExecute: allows configured unknown duration threshold', () => {
+  const action = new TestShutdownAction({
+    type: 'shutdown',
+    triggerMode: 'onlyThresholds',
+    thresholds: { battery: 50, runtime: 20, unknownMinutes: 10 },
+  });
+
+  assertEquals(
+    action.testShouldExecute(createMockContext({
+      powerStatus: 'unknown',
+      triggerReason: 'thresholdViolation',
+      unknownDurationMinutes: 10,
+    })),
+    true,
+  );
+
+  assertEquals(
+    action.testShouldExecute(createMockContext({
+      powerStatus: 'unknown',
+      triggerReason: 'powerStatusChange',
+      unknownDurationMinutes: 10,
+    })),
+    false,
+  );
+});
+
 Deno.test('ProxmoxAction.shouldExecute: allows confirmed battery events', () => {
   const powerChangeAction = new TestProxmoxAction({ type: 'proxmox' });
   const thresholdAction = new TestProxmoxAction({
@@ -1193,7 +1336,7 @@ Deno.test('ActionHandler.runEditProcess: updates an existing shutdown action', a
   } as unknown as ConstructorParameters<typeof ActionHandler>[0];
 
   const handler = new ActionHandler(nupstMock);
-  const answers = ['', '12', '25', '8', '3'];
+  const answers = ['', '12', '25', '8', '', '3'];
   let answerIndex = 0;
   const prompt = async (_question: string): Promise<string> => answers[answerIndex++] ?? '';
 
diff --git a/ts/action-orchestration.ts b/ts/action-orchestration.ts
index 0059b8f..a27e7df 100644
--- a/ts/action-orchestration.ts
+++ b/ts/action-orchestration.ts
@@ -15,6 +15,14 @@ export type TActionExecutionDecision =
   | { type: 'skip' }
   | { type: 'execute'; actions: IActionConfig[]; context: IActionContext };
 
+export function getUnknownStatusDurationMinutes(status: IUpsStatus, timestamp: number): number {
+  if (status.powerStatus !== 'unknown' && status.powerStatus !== 'unreachable') {
+    return 0;
+  }
+
+  return Math.max(0, (timestamp - status.lastStatusChange) / 60_000);
+}
+
 export function buildUpsActionContext(
   ups: IUpsActionSource,
   status: IUpsStatus,
@@ -29,6 +37,7 @@ export function buildUpsActionContext(
     batteryCapacity: status.batteryCapacity,
     batteryRuntime: status.batteryRuntime,
     previousPowerStatus: (previousStatus?.powerStatus || 'unknown') as TPowerStatus,
+    unknownDurationMinutes: getUnknownStatusDurationMinutes(status, timestamp),
     timestamp,
     triggerReason,
   };
diff --git a/ts/actions/base-action.ts b/ts/actions/base-action.ts
index 334cd03..46cc3bb 100644
--- a/ts/actions/base-action.ts
+++ b/ts/actions/base-action.ts
@@ -3,7 +3,7 @@
  *
  * Actions are triggered on:
  * 1. Power status changes (online ↔ onBattery)
- * 2. Threshold violations (battery/runtime cross below configured thresholds)
+ * 2. Threshold violations (battery/runtime or unknown-state duration cross configured thresholds)
  */
 
 export type TPowerStatus = 'online' | 'onBattery' | 'unknown' | 'unreachable';
@@ -30,6 +30,8 @@ export interface IActionContext {
   // State tracking
   /** Previous power status before this trigger */
   previousPowerStatus: TPowerStatus;
+  /** Minutes the UPS has continuously been unknown/unreachable. Zero for known states. */
+  unknownDurationMinutes: number;
 
   // Metadata
   /** Timestamp when this action was triggered (milliseconds since epoch) */
@@ -71,6 +73,8 @@ export interface IActionConfig {
     battery: number;
     /** Runtime threshold in minutes */
     runtime: number;
+    /** Optional fail-safe threshold for unknown/unreachable status duration in minutes */
+    unknownMinutes?: number;
   };
 
   // Shutdown action configuration
@@ -158,13 +162,13 @@ export abstract class Action {
       case 'onlyThresholds':
         // Only execute when this action's thresholds are exceeded
         if (!this.config.thresholds) return false; // No thresholds = never execute
-        return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime);
+        return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime, context);
 
       case 'powerChangesAndThresholds':
         // Execute on power changes OR when thresholds exceeded
         if (context.triggerReason === 'powerStatusChange') return true;
         if (!this.config.thresholds) return false;
-        return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime);
+        return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime, context);
 
       case 'anyChange':
         // Execute on every trigger (power change or threshold check)
@@ -176,19 +180,43 @@ export abstract class Action {
   }
 
   /**
-   * Check if current battery/runtime exceeds this action's thresholds
+   * Check if current UPS state exceeds this action's thresholds
    * @param batteryCapacity Current battery percentage
    * @param batteryRuntime Current runtime in minutes
    * @returns True if thresholds are exceeded
    */
-  protected areThresholdsExceeded(batteryCapacity: number, batteryRuntime: number): boolean {
+  protected areThresholdsExceeded(
+    batteryCapacity: number,
+    batteryRuntime: number,
+    context?: IActionContext,
+  ): boolean {
     if (!this.config.thresholds) {
       return false; // No thresholds configured
     }
 
+    if (context && this.isUnknownThresholdExceeded(context)) {
+      return true;
+    }
+
     return (
       batteryCapacity < this.config.thresholds.battery ||
       batteryRuntime < this.config.thresholds.runtime
     );
   }
+
+  protected isUnknownThresholdExceeded(context: IActionContext): boolean {
+    const unknownMinutes = this.config.thresholds?.unknownMinutes;
+    if (
+      typeof unknownMinutes !== 'number' ||
+      !Number.isFinite(unknownMinutes) ||
+      unknownMinutes < 0
+    ) {
+      return false;
+    }
+
+    return (
+      (context.powerStatus === 'unknown' || context.powerStatus === 'unreachable') &&
+      context.unknownDurationMinutes >= unknownMinutes
+    );
+  }
 }
diff --git a/ts/actions/proxmox-action.ts b/ts/actions/proxmox-action.ts
index 7e50bc4..a8d1032 100644
--- a/ts/actions/proxmox-action.ts
+++ b/ts/actions/proxmox-action.ts
@@ -34,6 +34,19 @@ export class ProxmoxAction extends Action {
     const mode = this.config.triggerMode || 'powerChangesAndThresholds';
 
     if (context.powerStatus !== 'onBattery') {
+      if (
+        context.triggerReason === 'thresholdViolation' &&
+        mode !== 'onlyPowerChanges' &&
+        this.isUnknownThresholdExceeded(context)
+      ) {
+        logger.warn(
+          `Proxmox action triggered: UPS ${context.powerStatus} for ${
+            context.unknownDurationMinutes.toFixed(1)
+          } minutes`,
+        );
+        return true;
+      }
+
       if (context.powerStatus === 'unreachable') {
         logger.info(
           'Proxmox action skipped: UPS is unreachable (communication failure, actual state unknown)',
@@ -52,7 +65,7 @@ export class ProxmoxAction extends Action {
         return false;
       }
 
-      return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime);
+      return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime, context);
     }
 
     if (context.triggerReason === 'powerStatusChange') {
diff --git a/ts/actions/script-action.ts b/ts/actions/script-action.ts
index 28b8a1a..fbe8d1d 100644
--- a/ts/actions/script-action.ts
+++ b/ts/actions/script-action.ts
@@ -112,11 +112,15 @@ export class ScriptAction extends Action {
       NUPST_POWER_STATUS: context.powerStatus,
       NUPST_BATTERY_CAPACITY: String(context.batteryCapacity),
       NUPST_BATTERY_RUNTIME: String(context.batteryRuntime),
+      NUPST_UNKNOWN_DURATION_MINUTES: String(context.unknownDurationMinutes),
       NUPST_TRIGGER_REASON: context.triggerReason,
       NUPST_TIMESTAMP: String(context.timestamp),
       // Include action's own thresholds if configured
       NUPST_BATTERY_THRESHOLD: this.config.thresholds ? String(this.config.thresholds.battery) : '',
       NUPST_RUNTIME_THRESHOLD: this.config.thresholds ? String(this.config.thresholds.runtime) : '',
+      NUPST_UNKNOWN_THRESHOLD_MINUTES: this.config.thresholds?.unknownMinutes !== undefined
+        ? String(this.config.thresholds.unknownMinutes)
+        : '',
     };
 
     // Build command with arguments
diff --git a/ts/actions/shutdown-action.ts b/ts/actions/shutdown-action.ts
index 941e531..210d76b 100644
--- a/ts/actions/shutdown-action.ts
+++ b/ts/actions/shutdown-action.ts
@@ -35,8 +35,21 @@ export class ShutdownAction extends Action {
 
     // CRITICAL SAFETY CHECK: Shutdown should NEVER trigger unless UPS is on battery
     // A low battery while on grid power is not an emergency (the battery is charging)
-    // When UPS is unreachable, we don't know the actual state - don't trigger false shutdown
+    // Unknown/unreachable status can only trigger after an explicit unknownMinutes threshold.
     if (context.powerStatus !== 'onBattery') {
+      if (
+        context.triggerReason === 'thresholdViolation' &&
+        mode !== 'onlyPowerChanges' &&
+        this.isUnknownThresholdExceeded(context)
+      ) {
+        logger.warn(
+          `Shutdown action triggered: UPS ${context.powerStatus} for ${
+            context.unknownDurationMinutes.toFixed(1)
+          } minutes`,
+        );
+        return true;
+      }
+
       if (context.powerStatus === 'unreachable') {
         logger.info(
           `Shutdown action skipped: UPS is unreachable (communication failure, actual state unknown)`,
@@ -57,7 +70,7 @@ export class ShutdownAction extends Action {
         return false;
       }
       // Check if thresholds are actually exceeded
-      return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime);
+      return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime, context);
     }
 
     // Handle power status changes
diff --git a/ts/actions/webhook-action.ts b/ts/actions/webhook-action.ts
index 7829522..a51e2b4 100644
--- a/ts/actions/webhook-action.ts
+++ b/ts/actions/webhook-action.ts
@@ -19,6 +19,8 @@ export interface IWebhookPayload {
   batteryCapacity: number;
   /** Current battery runtime in minutes */
   batteryRuntime: number;
+  /** Minutes the UPS has continuously been unknown/unreachable */
+  unknownDurationMinutes: number;
   /** Reason this webhook was triggered */
   triggerReason: 'powerStatusChange' | 'thresholdViolation';
   /** Timestamp when webhook was triggered */
@@ -27,6 +29,7 @@ export interface IWebhookPayload {
   thresholds?: {
     battery: number;
     runtime: number;
+    unknownMinutes?: number;
   };
 }
 
@@ -92,6 +95,7 @@ export class WebhookAction extends Action {
       powerStatus: context.powerStatus,
       batteryCapacity: context.batteryCapacity,
       batteryRuntime: context.batteryRuntime,
+      unknownDurationMinutes: context.unknownDurationMinutes,
       triggerReason: context.triggerReason,
       timestamp: context.timestamp,
     };
@@ -101,6 +105,9 @@ export class WebhookAction extends Action {
       payload.thresholds = {
         battery: this.config.thresholds.battery,
         runtime: this.config.thresholds.runtime,
+        ...(this.config.thresholds.unknownMinutes !== undefined
+          ? { unknownMinutes: this.config.thresholds.unknownMinutes }
+          : {}),
       };
     }
 
@@ -113,6 +120,7 @@ export class WebhookAction extends Action {
       url.searchParams.append('powerStatus', payload.powerStatus);
       url.searchParams.append('batteryCapacity', String(payload.batteryCapacity));
       url.searchParams.append('batteryRuntime', String(payload.batteryRuntime));
+      url.searchParams.append('unknownDurationMinutes', String(context.unknownDurationMinutes));
 
       url.searchParams.append('triggerReason', payload.triggerReason);
       url.searchParams.append('timestamp', String(payload.timestamp));
diff --git a/ts/cli/action-handler.ts b/ts/cli/action-handler.ts
index 1a65484..4120734 100644
--- a/ts/cli/action-handler.ts
+++ b/ts/cli/action-handler.ts
@@ -242,10 +242,13 @@ export class ActionHandler {
       logger.success(`Action removed from ${targetType} ${targetName}`);
       logger.log(`  ${theme.dim('Type:')} ${removedAction.type}`);
       if (removedAction.thresholds) {
+        const unknownThreshold = removedAction.thresholds.unknownMinutes !== undefined
+          ? `, Unknown: ${removedAction.thresholds.unknownMinutes}min`
+          : '';
         logger.log(
           `  ${
             theme.dim('Thresholds:')
-          } Battery: ${removedAction.thresholds.battery}%, Runtime: ${removedAction.thresholds.runtime}min`,
+          } Battery: ${removedAction.thresholds.battery}%, Runtime: ${removedAction.thresholds.runtime}min${unknownThreshold}`,
         );
       }
       logger.log(`  ${theme.dim('Changes saved and will be applied automatically')}`);
@@ -703,7 +706,31 @@ export class ActionHandler {
       logger.error('Invalid runtime threshold. Must be >= 0.');
       process.exit(1);
     }
-    newAction.thresholds = { battery, runtime };
+    const thresholds: NonNullable<IActionConfig['thresholds']> = { battery, runtime };
+
+    const currentUnknownThreshold = existingAction?.thresholds?.unknownMinutes;
+    const unknownPrompt = currentUnknownThreshold !== undefined
+      ? `  ${theme.dim('Unknown/unreachable threshold')} ${
+        theme.dim(`(minutes, 'clear' = disabled) [${currentUnknownThreshold}]:`)
+      } `
+      : `  ${theme.dim('Unknown/unreachable threshold')} ${
+        theme.dim('(minutes, empty = disabled):')
+      } `;
+    const unknownInput = await prompt(unknownPrompt);
+    if (this.isClearInput(unknownInput)) {
+      // Leave disabled.
+    } else if (unknownInput.trim()) {
+      const unknownMinutes = parseInt(unknownInput, 10);
+      if (isNaN(unknownMinutes) || unknownMinutes < 0) {
+        logger.error('Invalid unknown/unreachable threshold. Must be >= 0.');
+        process.exit(1);
+      }
+      thresholds.unknownMinutes = unknownMinutes;
+    } else if (currentUnknownThreshold !== undefined) {
+      thresholds.unknownMinutes = currentUnknownThreshold;
+    }
+
+    newAction.thresholds = thresholds;
 
     logger.log('');
     logger.log(`  ${theme.dim('Trigger mode:')}`);
@@ -758,6 +785,7 @@ export class ActionHandler {
       { header: 'Type', key: 'type', align: 'left' },
       { header: 'Battery', key: 'battery', align: 'right' },
       { header: 'Runtime', key: 'runtime', align: 'right' },
+      { header: 'Unknown', key: 'unknown', align: 'right' },
       { header: 'Trigger Mode', key: 'triggerMode', align: 'left' },
       { header: 'Details', key: 'details', align: 'left' },
     ];
@@ -792,6 +820,9 @@ export class ActionHandler {
         type: theme.highlight(action.type),
         battery: action.thresholds ? `${action.thresholds.battery}%` : theme.dim('N/A'),
         runtime: action.thresholds ? `${action.thresholds.runtime}min` : theme.dim('N/A'),
+        unknown: action.thresholds?.unknownMinutes !== undefined
+          ? `${action.thresholds.unknownMinutes}min`
+          : theme.dim('off'),
         triggerMode: theme.dim(action.triggerMode || 'onlyThresholds'),
         details,
       };
diff --git a/ts/cli/ups-handler.ts b/ts/cli/ups-handler.ts
index 305c160..2a4ef67 100644
--- a/ts/cli/ups-handler.ts
+++ b/ts/cli/ups-handler.ts
@@ -1318,7 +1318,10 @@ export class UpsHandler {
         logger.log('');
         logger.info('Action Thresholds:');
         logger.dim(
-          'Action will trigger when battery or runtime falls below these values (while on battery)',
+          'Action will trigger when battery/runtime falls below these values while on battery.',
+        );
+        logger.dim(
+          'Optionally, it can also trigger after the UPS has been unknown/unreachable for N minutes.',
         );
 
         const batteryInput = await prompt('Battery threshold percentage [60]: ');
@@ -1329,10 +1332,18 @@ export class UpsHandler {
         const runtime = parseInt(runtimeInput, 10);
         const runtimeThreshold = (runtimeInput.trim() && !isNaN(runtime)) ? runtime : 20;
 
+        const unknownInput = await prompt(
+          'Unknown/unreachable threshold in minutes (empty = disabled): ',
+        );
+        const unknownMinutes = parseInt(unknownInput, 10);
+
         action.thresholds = {
           battery: batteryThreshold,
           runtime: runtimeThreshold,
         };
+        if (unknownInput.trim() && !isNaN(unknownMinutes) && unknownMinutes >= 0) {
+          action.thresholds.unknownMinutes = unknownMinutes;
+        }
       }
 
       actions.push(action as IActionConfig);
diff --git a/ts/daemon.ts b/ts/daemon.ts
index 35f888b..97c5424 100644
--- a/ts/daemon.ts
+++ b/ts/daemon.ts
@@ -38,6 +38,7 @@ import {
   ensureUpsStatus,
   getActionThresholdStates,
   getEnteredThresholdIndexes,
+  getUnknownStatusDurationMinutes,
 } from './ups-monitoring.ts';
 import {
   buildShutdownErrorRow,
@@ -653,10 +654,11 @@ export class NupstDaemon {
         }
 
         const thresholdStates = getActionThresholdStates(
-          status.powerStatus,
-          status.batteryCapacity,
-          status.batteryRuntime,
+          pollSnapshot.updatedStatus.powerStatus,
+          pollSnapshot.updatedStatus.batteryCapacity,
+          pollSnapshot.updatedStatus.batteryRuntime,
           ups.actions,
+          getUnknownStatusDurationMinutes(pollSnapshot.updatedStatus, currentTime),
         );
         const enteredThresholdIndexes = this.trackEnteredThresholdIndexes(
           `ups:${ups.id}`,
@@ -706,6 +708,28 @@ export class NupstDaemon {
           );
         }
 
+        const thresholdStates = getActionThresholdStates(
+          failureSnapshot.updatedStatus.powerStatus,
+          failureSnapshot.updatedStatus.batteryCapacity,
+          failureSnapshot.updatedStatus.batteryRuntime,
+          ups.actions,
+          getUnknownStatusDurationMinutes(failureSnapshot.updatedStatus, currentTime),
+        );
+        const enteredThresholdIndexes = this.trackEnteredThresholdIndexes(
+          `ups:${ups.id}`,
+          thresholdStates,
+        );
+
+        if (enteredThresholdIndexes.length > 0) {
+          await this.triggerUpsActions(
+            ups,
+            failureSnapshot.updatedStatus,
+            failureSnapshot.previousStatus,
+            'thresholdViolation',
+            enteredThresholdIndexes,
+          );
+        }
+
         this.upsStatus.set(ups.id, failureSnapshot.updatedStatus);
       }
     }
@@ -769,7 +793,7 @@ export class NupstDaemon {
       }
 
       const thresholdEvaluations = (group.actions || []).map((action) =>
-        evaluateGroupActionThreshold(action, group.mode, memberStatuses)
+        evaluateGroupActionThreshold(action, group.mode, memberStatuses, currentTime)
       );
       const thresholdStates = thresholdEvaluations.map((evaluation) =>
         evaluation.exceedsThreshold && !evaluation.blockedByUnreachable
diff --git a/ts/group-monitoring.ts b/ts/group-monitoring.ts
index 57f7c68..e8e75b1 100644
--- a/ts/group-monitoring.ts
+++ b/ts/group-monitoring.ts
@@ -1,4 +1,5 @@
 import type { IActionConfig, TPowerStatus } from './actions/base-action.ts';
+import { getUnknownStatusDurationMinutes, isActionThresholdExceeded } from './ups-monitoring.ts';
 import { createInitialUpsStatus, type IUpsIdentity, type IUpsStatus } from './ups-status.ts';
 
 export interface IGroupStatusSnapshot {
@@ -10,6 +11,7 @@ export interface IGroupStatusSnapshot {
 export interface IGroupThresholdEvaluation {
   exceedsThreshold: boolean;
   blockedByUnreachable: boolean;
+  exceededByUnknownDuration: boolean;
   representativeStatus?: IUpsStatus;
 }
 
@@ -143,11 +145,13 @@ export function evaluateGroupActionThreshold(
   actionConfig: IActionConfig,
   mode: 'redundant' | 'nonRedundant',
   memberStatuses: IUpsStatus[],
+  currentTime: number = Date.now(),
 ): IGroupThresholdEvaluation {
   if (!actionConfig.thresholds || memberStatuses.length === 0) {
     return {
       exceedsThreshold: false,
       blockedByUnreachable: false,
+      exceededByUnknownDuration: false,
     };
   }
 
@@ -156,16 +160,32 @@ export function evaluateGroupActionThreshold(
     (status.batteryCapacity < actionConfig.thresholds!.battery ||
       status.batteryRuntime < actionConfig.thresholds!.runtime)
   );
-  const exceedsThreshold = mode === 'redundant'
+
+  const unknownMembers = memberStatuses.filter((status) =>
+    isActionThresholdExceeded(
+      actionConfig,
+      status.powerStatus,
+      status.batteryCapacity,
+      status.batteryRuntime,
+      getUnknownStatusDurationMinutes(status, currentTime),
+    ) && (status.powerStatus === 'unknown' || status.powerStatus === 'unreachable')
+  );
+
+  const exceedsBatteryThreshold = mode === 'redundant'
     ? criticalMembers.length === memberStatuses.length
     : criticalMembers.length > 0;
+  const exceededByUnknownDuration = mode === 'redundant'
+    ? unknownMembers.length === memberStatuses.length
+    : unknownMembers.length > 0;
+  const exceedsThreshold = exceedsBatteryThreshold || exceededByUnknownDuration;
 
   return {
     exceedsThreshold,
-    blockedByUnreachable: exceedsThreshold &&
+    blockedByUnreachable: exceedsBatteryThreshold && !exceededByUnknownDuration &&
       destructiveActionTypes.has(actionConfig.type) &&
       memberStatuses.some((status) => status.powerStatus === 'unreachable'),
-    representativeStatus: selectWorstStatus(criticalMembers),
+    exceededByUnknownDuration,
+    representativeStatus: selectWorstStatus([...criticalMembers, ...unknownMembers]),
   };
 }
 
@@ -181,18 +201,23 @@ export function buildGroupThresholdContextStatus(
     .filter((status): status is IUpsStatus => !!status);
 
   const representative = selectWorstStatus(representativeStatuses) || fallbackStatus;
+  const powerStatus = representative.powerStatus === 'unknown' ||
+      representative.powerStatus === 'unreachable'
+    ? representative.powerStatus
+    : 'onBattery';
 
   return {
     ...fallbackStatus,
     id: group.id,
     name: group.name,
-    powerStatus: 'onBattery',
+    powerStatus,
     batteryCapacity: representative.batteryCapacity,
     batteryRuntime: representative.batteryRuntime,
     outputLoad: representative.outputLoad,
     outputPower: representative.outputPower,
     outputVoltage: representative.outputVoltage,
     outputCurrent: representative.outputCurrent,
+    lastStatusChange: representative.lastStatusChange,
     lastCheckTime: currentTime,
   };
 }
diff --git a/ts/systemd.ts b/ts/systemd.ts
index faca645..d627c5b 100644
--- a/ts/systemd.ts
+++ b/ts/systemd.ts
@@ -512,6 +512,9 @@ WantedBy=multi-user.target
             actionDesc += ` (${
               action.triggerMode || 'onlyThresholds'
             }: battery<${action.thresholds.battery}%, runtime<${action.thresholds.runtime}min`;
+            if (action.thresholds.unknownMinutes !== undefined) {
+              actionDesc += `, unknown>${action.thresholds.unknownMinutes}min`;
+            }
             if (action.type === 'shutdown') {
               const shutdownDelay = action.shutdownDelay ?? defaultShutdownDelay;
               actionDesc += `, delay=${shutdownDelay}min`;
@@ -599,6 +602,9 @@ WantedBy=multi-user.target
             actionDesc += ` (${
               action.triggerMode || 'onlyThresholds'
             }: battery<${action.thresholds.battery}%, runtime<${action.thresholds.runtime}min`;
+            if (action.thresholds.unknownMinutes !== undefined) {
+              actionDesc += `, unknown>${action.thresholds.unknownMinutes}min`;
+            }
             if (action.type === 'shutdown') {
               const shutdownDelay = action.shutdownDelay ?? defaultShutdownDelay;
               actionDesc += `, delay=${shutdownDelay}min`;
diff --git a/ts/ups-monitoring.ts b/ts/ups-monitoring.ts
index e9583ce..19b7f85 100644
--- a/ts/ups-monitoring.ts
+++ b/ts/ups-monitoring.ts
@@ -1,4 +1,5 @@
 import type { IActionConfig } from './actions/base-action.ts';
+import { getUnknownStatusDurationMinutes } from './action-orchestration.ts';
 import { NETWORK } from './constants.ts';
 import type { IUpsStatus as IProtocolUpsStatus } from './snmp/types.ts';
 import { createInitialUpsStatus, type IUpsIdentity, type IUpsStatus } from './ups-status.ts';
@@ -119,8 +120,15 @@ export function hasThresholdViolation(
   batteryCapacity: number,
   batteryRuntime: number,
   actions: IActionConfig[] | undefined,
+  unknownDurationMinutes: number = 0,
 ): boolean {
-  return getActionThresholdStates(powerStatus, batteryCapacity, batteryRuntime, actions).some(
+  return getActionThresholdStates(
+    powerStatus,
+    batteryCapacity,
+    batteryRuntime,
+    actions,
+    unknownDurationMinutes,
+  ).some(
     Boolean,
   );
 }
@@ -130,8 +138,23 @@ export function isActionThresholdExceeded(
   powerStatus: IProtocolUpsStatus['powerStatus'],
   batteryCapacity: number,
   batteryRuntime: number,
+  unknownDurationMinutes: number = 0,
 ): boolean {
-  if (powerStatus !== 'onBattery' || !actionConfig.thresholds) {
+  if (!actionConfig.thresholds) {
+    return false;
+  }
+
+  const unknownMinutes = actionConfig.thresholds.unknownMinutes;
+  if (
+    (powerStatus === 'unknown' || powerStatus === 'unreachable') &&
+    typeof unknownMinutes === 'number' &&
+    Number.isFinite(unknownMinutes) &&
+    unknownMinutes >= 0
+  ) {
+    return unknownDurationMinutes >= unknownMinutes;
+  }
+
+  if (powerStatus !== 'onBattery') {
     return false;
   }
 
@@ -146,16 +169,25 @@ export function getActionThresholdStates(
   batteryCapacity: number,
   batteryRuntime: number,
   actions: IActionConfig[] | undefined,
+  unknownDurationMinutes: number = 0,
 ): boolean[] {
   if (!actions || actions.length === 0) {
     return [];
   }
 
   return actions.map((actionConfig) =>
-    isActionThresholdExceeded(actionConfig, powerStatus, batteryCapacity, batteryRuntime)
+    isActionThresholdExceeded(
+      actionConfig,
+      powerStatus,
+      batteryCapacity,
+      batteryRuntime,
+      unknownDurationMinutes,
+    )
   );
 }
 
+export { getUnknownStatusDurationMinutes };
+
 export function getEnteredThresholdIndexes(
   previousStates: boolean[] | undefined,
   currentStates: boolean[],