add low battery alert (#1507)

agent/docker_test.go

@@ -1053,53 +1053,6 @@ func TestDecodeDockerLogStreamMemoryProtection(t *testing.T) {
 	})
 }
 
-func TestAllocateBuffer(t *testing.T) {
-	tests := []struct {
-		name          string
-		currentCap    int
-		needed        int
-		expectedCap   int
-		shouldRealloc bool
-	}{
-		{
-			name:          "buffer has enough capacity",
-			currentCap:    1024,
-			needed:        512,
-			expectedCap:   1024,
-			shouldRealloc: false,
-		},
-		{
-			name:          "buffer needs reallocation",
-			currentCap:    512,
-			needed:        1024,
-			expectedCap:   1024,
-			shouldRealloc: true,
-		},
-		{
-			name:          "buffer needs exact size",
-			currentCap:    1024,
-			needed:        1024,
-			expectedCap:   1024,
-			shouldRealloc: false,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			current := make([]byte, 0, tt.currentCap)
-			result := allocateBuffer(current, tt.needed)
-
-			assert.Equal(t, tt.needed, len(result))
-			assert.GreaterOrEqual(t, cap(result), tt.expectedCap)
-
-			if tt.shouldRealloc {
-				// If reallocation was needed, capacity should be at least the needed size
-				assert.GreaterOrEqual(t, cap(result), tt.needed)
-			}
-		})
-	}
-}
-
 func TestShouldExcludeContainer(t *testing.T) {
 	tests := []struct {
 		name          string
@@ -1259,4 +1212,3 @@ func TestAnsiEscapePattern(t *testing.T) {
 		})
 	}
 }
-

internal/alerts/alerts.go

@@ -49,6 +49,7 @@ type SystemAlertStats struct {
 	GPU          map[string]SystemAlertGPUData `json:"g"`
 	Temperatures map[string]float32            `json:"t"`
 	LoadAvg      [3]float64                    `json:"la"`
+	Battery      [2]uint8                      `json:"bat"`
 }
 
 type SystemAlertGPUData struct {

internal/alerts/alerts_battery_test.go

@@ -0,0 +1,387 @@
+//go:build testing
+// +build testing
+
+package alerts_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/internal/entities/system"
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/tools/types"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestBatteryAlertLogic tests that battery alerts trigger when value drops BELOW threshold
+// (opposite of other alerts like CPU, Memory, etc. which trigger when exceeding threshold)
+func TestBatteryAlertLogic(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	// Create a system
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+	require.NoError(t, err)
+	systemRecord := systems[0]
+
+	// Create a battery alert with threshold of 20% and min of 1 minute (immediate trigger)
+	batteryAlert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":   "Battery",
+		"system": systemRecord.Id,
+		"user":   user.Id,
+		"value":  20, // threshold: 20%
+		"min":    1,  // 1 minute (immediate trigger for testing)
+	})
+	require.NoError(t, err)
+
+	// Verify alert is not triggered initially
+	assert.False(t, batteryAlert.GetBool("triggered"), "Alert should not be triggered initially")
+
+	// Create system stats with battery at 50% (above threshold - should NOT trigger)
+	statsHigh := system.Stats{
+		Cpu:     10,
+		MemPct:  30,
+		DiskPct: 40,
+		Battery: [2]uint8{50, 1}, // 50% battery, discharging
+	}
+	statsHighJSON, _ := json.Marshal(statsHigh)
+	_, err = beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+		"system": systemRecord.Id,
+		"type":   "1m",
+		"stats":  string(statsHighJSON),
+	})
+	require.NoError(t, err)
+
+	// Create CombinedData for the alert handler
+	combinedDataHigh := &system.CombinedData{
+		Stats: statsHigh,
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Simulate system update time
+	systemRecord.Set("updated", time.Now().UTC())
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts with high battery
+	am := hub.GetAlertManager()
+	err = am.HandleSystemAlerts(systemRecord, combinedDataHigh)
+	require.NoError(t, err)
+
+	// Verify alert is still NOT triggered (battery 50% is above threshold 20%)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.False(t, batteryAlert.GetBool("triggered"), "Alert should NOT be triggered when battery (50%%) is above threshold (20%%)")
+
+	// Now create stats with battery at 15% (below threshold - should trigger)
+	statsLow := system.Stats{
+		Cpu:     10,
+		MemPct:  30,
+		DiskPct: 40,
+		Battery: [2]uint8{15, 1}, // 15% battery, discharging
+	}
+	statsLowJSON, _ := json.Marshal(statsLow)
+	_, err = beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+		"system": systemRecord.Id,
+		"type":   "1m",
+		"stats":  string(statsLowJSON),
+	})
+	require.NoError(t, err)
+
+	combinedDataLow := &system.CombinedData{
+		Stats: statsLow,
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Update system timestamp
+	systemRecord.Set("updated", time.Now().UTC())
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts with low battery
+	err = am.HandleSystemAlerts(systemRecord, combinedDataLow)
+	require.NoError(t, err)
+
+	// Wait for the alert to be processed
+	time.Sleep(20 * time.Millisecond)
+
+	// Verify alert IS triggered (battery 15% is below threshold 20%)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.True(t, batteryAlert.GetBool("triggered"), "Alert SHOULD be triggered when battery (15%%) drops below threshold (20%%)")
+
+	// Now test resolution: battery goes back above threshold
+	statsRecovered := system.Stats{
+		Cpu:     10,
+		MemPct:  30,
+		DiskPct: 40,
+		Battery: [2]uint8{25, 1}, // 25% battery, discharging
+	}
+	statsRecoveredJSON, _ := json.Marshal(statsRecovered)
+	_, err = beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+		"system": systemRecord.Id,
+		"type":   "1m",
+		"stats":  string(statsRecoveredJSON),
+	})
+	require.NoError(t, err)
+
+	combinedDataRecovered := &system.CombinedData{
+		Stats: statsRecovered,
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Update system timestamp
+	systemRecord.Set("updated", time.Now().UTC())
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts with recovered battery
+	err = am.HandleSystemAlerts(systemRecord, combinedDataRecovered)
+	require.NoError(t, err)
+
+	// Wait for the alert to be processed
+	time.Sleep(20 * time.Millisecond)
+
+	// Verify alert is now resolved (battery 25% is above threshold 20%)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.False(t, batteryAlert.GetBool("triggered"), "Alert should be resolved when battery (25%%) goes above threshold (20%%)")
+}
+
+// TestBatteryAlertNoBattery verifies that systems without battery data don't trigger alerts
+func TestBatteryAlertNoBattery(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	// Create a system
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+	require.NoError(t, err)
+	systemRecord := systems[0]
+
+	// Create a battery alert
+	batteryAlert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":   "Battery",
+		"system": systemRecord.Id,
+		"user":   user.Id,
+		"value":  20,
+		"min":    1,
+	})
+	require.NoError(t, err)
+
+	// Create stats with NO battery data (Battery[0] = 0)
+	statsNoBattery := system.Stats{
+		Cpu:     10,
+		MemPct:  30,
+		DiskPct: 40,
+		Battery: [2]uint8{0, 0}, // No battery
+	}
+
+	combinedData := &system.CombinedData{
+		Stats: statsNoBattery,
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Simulate system update time
+	systemRecord.Set("updated", time.Now().UTC())
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts
+	am := hub.GetAlertManager()
+	err = am.HandleSystemAlerts(systemRecord, combinedData)
+	require.NoError(t, err)
+
+	// Wait a moment for processing
+	time.Sleep(20 * time.Millisecond)
+
+	// Verify alert is NOT triggered (no battery data should skip the alert)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.False(t, batteryAlert.GetBool("triggered"), "Alert should NOT be triggered when system has no battery")
+}
+
+// TestBatteryAlertAveragedSamples tests battery alerts with min > 1 (averaging multiple samples)
+// This ensures the inverted threshold logic works correctly across averaged time windows
+func TestBatteryAlertAveragedSamples(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	// Create a system
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+	require.NoError(t, err)
+	systemRecord := systems[0]
+
+	// Create a battery alert with threshold of 25% and min of 2 minutes (requires averaging)
+	batteryAlert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":   "Battery",
+		"system": systemRecord.Id,
+		"user":   user.Id,
+		"value":  25, // threshold: 25%
+		"min":    2,  // 2 minutes - requires averaging
+	})
+	require.NoError(t, err)
+
+	// Verify alert is not triggered initially
+	assert.False(t, batteryAlert.GetBool("triggered"), "Alert should not be triggered initially")
+
+	am := hub.GetAlertManager()
+	now := time.Now().UTC()
+
+	// Create system_stats records with low battery (below threshold)
+	// The alert has min=2 minutes, so alert.time = now - 2 minutes
+	// For the alert to be valid, alert.time must be AFTER the oldest record's created time
+	// So we need records older than (now - 2 min), plus records within the window
+	// Records at: now-3min (oldest, before window), now-90s, now-60s, now-30s
+	recordTimes := []time.Duration{
+		-180 * time.Second, // 3 min ago - this makes the oldest record before alert.time
+		-90 * time.Second,
+		-60 * time.Second,
+		-30 * time.Second,
+	}
+
+	for _, offset := range recordTimes {
+		statsLow := system.Stats{
+			Cpu:     10,
+			MemPct:  30,
+			DiskPct: 40,
+			Battery: [2]uint8{15, 1}, // 15% battery (below 25% threshold)
+		}
+		statsLowJSON, _ := json.Marshal(statsLow)
+
+		recordTime := now.Add(offset)
+		record, err := beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+			"system": systemRecord.Id,
+			"type":   "1m",
+			"stats":  string(statsLowJSON),
+		})
+		require.NoError(t, err)
+		// Update created time to simulate historical records - use SetRaw with formatted string
+		record.SetRaw("created", recordTime.Format(types.DefaultDateLayout))
+		err = hub.SaveNoValidate(record)
+		require.NoError(t, err)
+	}
+
+	// Create combined data with low battery
+	combinedDataLow := &system.CombinedData{
+		Stats: system.Stats{
+			Cpu:     10,
+			MemPct:  30,
+			DiskPct: 40,
+			Battery: [2]uint8{15, 1},
+		},
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Update system timestamp
+	systemRecord.Set("updated", now)
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts - should trigger because average battery is below threshold
+	err = am.HandleSystemAlerts(systemRecord, combinedDataLow)
+	require.NoError(t, err)
+
+	// Wait for alert processing
+	time.Sleep(20 * time.Millisecond)
+
+	// Verify alert IS triggered (average battery 15% is below threshold 25%)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.True(t, batteryAlert.GetBool("triggered"),
+		"Alert SHOULD be triggered when average battery (15%%) is below threshold (25%%) over min period")
+
+	// Now add records with high battery to test resolution
+	// Use a new time window 2 minutes later
+	newNow := now.Add(2 * time.Minute)
+	// Records need to span before the alert time window (newNow - 2 min)
+	recordTimesHigh := []time.Duration{
+		-180 * time.Second, // 3 min before newNow - makes oldest record before alert.time
+		-90 * time.Second,
+		-60 * time.Second,
+		-30 * time.Second,
+	}
+
+	for _, offset := range recordTimesHigh {
+		statsHigh := system.Stats{
+			Cpu:     10,
+			MemPct:  30,
+			DiskPct: 40,
+			Battery: [2]uint8{50, 1}, // 50% battery (above 25% threshold)
+		}
+		statsHighJSON, _ := json.Marshal(statsHigh)
+
+		recordTime := newNow.Add(offset)
+		record, err := beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+			"system": systemRecord.Id,
+			"type":   "1m",
+			"stats":  string(statsHighJSON),
+		})
+		require.NoError(t, err)
+		record.SetRaw("created", recordTime.Format(types.DefaultDateLayout))
+		err = hub.SaveNoValidate(record)
+		require.NoError(t, err)
+	}
+
+	// Create combined data with high battery
+	combinedDataHigh := &system.CombinedData{
+		Stats: system.Stats{
+			Cpu:     10,
+			MemPct:  30,
+			DiskPct: 40,
+			Battery: [2]uint8{50, 1},
+		},
+		Info: system.Info{
+			Hostname: "test-host",
+			Cpu:      10,
+			MemPct:   30,
+			DiskPct:  40,
+		},
+	}
+
+	// Update system timestamp to the new time window
+	systemRecord.Set("updated", newNow)
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	// Handle system alerts - should resolve because average battery is now above threshold
+	err = am.HandleSystemAlerts(systemRecord, combinedDataHigh)
+	require.NoError(t, err)
+
+	// Wait for alert processing
+	time.Sleep(20 * time.Millisecond)
+
+	// Verify alert is resolved (average battery 50% is above threshold 25%)
+	batteryAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": batteryAlert.Id})
+	require.NoError(t, err)
+	assert.False(t, batteryAlert.GetBool("triggered"),
+		"Alert should be resolved when average battery (50%%) is above threshold (25%%) over min period")
+}

internal/alerts/alerts_system.go

@@ -66,17 +66,30 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 			unit = ""
 		case "GPU":
 			val = data.Info.GpuPct
+		case "Battery":
+			if data.Stats.Battery[0] == 0 {
+				continue
+			}
+			val = float64(data.Stats.Battery[0])
 		}
 
 		triggered := alertRecord.GetBool("triggered")
 		threshold := alertRecord.GetFloat("value")
 
+		// Battery alert has inverted logic: trigger when value is BELOW threshold
+		lowAlert := isLowAlert(name)
+
 		// CONTINUE
-		// IF alert is not triggered and curValue is less than threshold
+		// For normal alerts: IF not triggered and curValue <= threshold, OR triggered and curValue > threshold
-		// OR alert is triggered and curValue is greater than threshold
+		// For low alerts (Battery): IF not triggered and curValue >= threshold, OR triggered and curValue < threshold
-		if (!triggered && val <= threshold) || (triggered && val > threshold) {
+		if lowAlert {
-			// log.Printf("Skipping alert %s: val %f | threshold %f | triggered %v\n", name, val, threshold, triggered)
+			if (!triggered && val >= threshold) || (triggered && val < threshold) {
-			continue
+				continue
+			}
+		} else {
+			if (!triggered && val <= threshold) || (triggered && val > threshold) {
+				continue
+			}
 		}
 
 		min := max(1, cast.ToUint8(alertRecord.Get("min")))
@@ -94,7 +107,11 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 
 		// send alert immediately if min is 1 - no need to sum up values.
 		if min == 1 {
-			alert.triggered = val > threshold
+			if lowAlert {
+				alert.triggered = val < threshold
+			} else {
+				alert.triggered = val > threshold
+			}
 			go am.sendSystemAlert(alert)
 			continue
 		}
@@ -219,6 +236,8 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 					}
 				}
 				alert.val += maxUsage
+			case "Battery":
+				alert.val += float64(stats.Battery[0])
 			default:
 				continue
 			}
@@ -256,12 +275,24 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 		// log.Printf("%s: val %f | count %d | min-count %f | threshold %f\n", alert.name, alert.val, alert.count, minCount, alert.threshold)
 		// pass through alert if count is greater than or equal to minCount
 		if float32(alert.count) >= minCount {
-			if !alert.triggered && alert.val > alert.threshold {
+			// Battery alert has inverted logic: trigger when value is BELOW threshold
-				alert.triggered = true
+			lowAlert := isLowAlert(alert.name)
-				go am.sendSystemAlert(alert)
+			if lowAlert {
-			} else if alert.triggered && alert.val <= alert.threshold {
+				if !alert.triggered && alert.val < alert.threshold {
-				alert.triggered = false
+					alert.triggered = true
-				go am.sendSystemAlert(alert)
+					go am.sendSystemAlert(alert)
+				} else if alert.triggered && alert.val >= alert.threshold {
+					alert.triggered = false
+					go am.sendSystemAlert(alert)
+				}
+			} else {
+				if !alert.triggered && alert.val > alert.threshold {
+					alert.triggered = true
+					go am.sendSystemAlert(alert)
+				} else if alert.triggered && alert.val <= alert.threshold {
+					alert.triggered = false
+					go am.sendSystemAlert(alert)
+				}
 			}
 		}
 	}
@@ -288,10 +319,19 @@ func (am *AlertManager) sendSystemAlert(alert SystemAlertData) {
 	}
 
 	var subject string
+	lowAlert := isLowAlert(alert.name)
 	if alert.triggered {
-		subject = fmt.Sprintf("%s %s above threshold", systemName, titleAlertName)
+		if lowAlert {
+			subject = fmt.Sprintf("%s %s below threshold", systemName, titleAlertName)
+		} else {
+			subject = fmt.Sprintf("%s %s above threshold", systemName, titleAlertName)
+		}
 	} else {
-		subject = fmt.Sprintf("%s %s below threshold", systemName, titleAlertName)
+		if lowAlert {
+			subject = fmt.Sprintf("%s %s above threshold", systemName, titleAlertName)
+		} else {
+			subject = fmt.Sprintf("%s %s below threshold", systemName, titleAlertName)
+		}
 	}
 	minutesLabel := "minute"
 	if alert.min > 1 {
@@ -316,3 +356,7 @@ func (am *AlertManager) sendSystemAlert(alert SystemAlertData) {
 		LinkText: "View " + systemName,
 	})
 }
+
+func isLowAlert(name string) bool {
+	return name == "Battery"
+}

internal/migrations/0_collections_snapshot_0_17_1_dev_0.go

@@ -78,7 +78,8 @@ func init() {
 					"GPU",
 					"LoadAvg1",
 					"LoadAvg5",
-					"LoadAvg15"
+					"LoadAvg15",
+					"Battery"
 				]
 			},
 			{

internal/site/src/components/alerts/alerts-sheet.tsx

@@ -245,13 +245,23 @@ export function AlertContent({
 						{!singleDescription && (
 							<div>
 								<p id={`v${name}`} className="text-sm block h-8">
-									<Trans>
+									{alertKey === "Battery" ? (
-										Average exceeds{" "}
+										<Trans>
-										<strong className="text-foreground">
+											Average drops below{" "}
-											{value}
+											<strong className="text-foreground">
-											{alertData.unit}
+												{value}
-										</strong>
+												{alertData.unit}
-									</Trans>
+											</strong>
+										</Trans>
+									) : (
+										<Trans>
+											Average exceeds{" "}
+											<strong className="text-foreground">
+												{value}
+												{alertData.unit}
+											</strong>
+										</Trans>
+									)}
 								</p>
 								<div className="flex gap-3">
 									<Slider

internal/site/src/components/ui/icons.tsx

@@ -139,3 +139,11 @@ export function WebSocketIcon(props: SVGProps<SVGSVGElement>) {
 		</svg>
 	)
 }
+
+export function BatteryIcon(props: SVGProps<SVGSVGElement>) {
+	return (
+		<svg viewBox="0 0 256 256" {...props} fill="currentColor">
+			<path d="M176,32H80A24,24,0,0,0,56,56V224a24,24,0,0,0,24,24h96a24,24,0,0,0,24-24V56A24,24,0,0,0,176,32Zm8,192a8,8,0,0,1-8,8H80a8,8,0,0,1-8-8V56a8,8,0,0,1,8-8h96a8,8,0,0,1,8,8Zm-16-24a8,8,0,0,1-8,8H96a8,8,0,0,1,0-16h64A8,8,0,0,1,168,200ZM88,8a8,8,0,0,1,8-8h64a8,8,0,0,1,0,16H96A8,8,0,0,1,88,8Zm80,152a8,8,0,0,1-8,8H96a8,8,0,0,1,0-16h64A8,8,0,0,1,168,160Z"></path>
+		</svg>
+	)
+}

internal/site/src/lib/alerts.ts

@@ -1,10 +1,11 @@
 import { t } from "@lingui/core/macro"
-import { CpuIcon, HardDriveIcon, HourglassIcon, MemoryStickIcon, ServerIcon, ThermometerIcon } from "lucide-react"
+import { CpuIcon, HardDriveIcon, MemoryStickIcon, ServerIcon } from "lucide-react"
 import type { RecordSubscription } from "pocketbase"
 import { EthernetIcon, GpuIcon } from "@/components/ui/icons"
 import { $alerts } from "@/lib/stores"
 import type { AlertInfo, AlertRecord } from "@/types"
 import { pb } from "./api"
+import { ThermometerIcon, BatteryIcon, HourglassIcon } from "@/components/ui/icons"
 
 /** Alert info for each alert type */
 export const alertInfo: Record<string, AlertInfo> = {
@@ -83,6 +84,13 @@ export const alertInfo: Record<string, AlertInfo> = {
 		step: 0.1,
 		desc: () => t`Triggers when 15 minute load average exceeds a threshold`,
 	},
+	Battery: {
+		name: () => t`Battery`,
+		unit: "%",
+		icon: BatteryIcon,
+		desc: () => t`Triggers when battery charge drops below a threshold`,
+		start: 20,
+	},
 } as const
 
 /** Helper to manage user alerts */