diff --git a/app/src/main/java/io/heckel/ntfy/db/Repository.kt b/app/src/main/java/io/heckel/ntfy/db/Repository.kt
index bf3f0c1..36592e7 100644
--- a/app/src/main/java/io/heckel/ntfy/db/Repository.kt
+++ b/app/src/main/java/io/heckel/ntfy/db/Repository.kt
@@ -225,6 +225,16 @@ class Repository(private val sharedPrefs: SharedPreferences, private val subscri
             .apply()
     }
 
+    fun getBatteryOptimizationsRemindTime(): Long {
+        return sharedPrefs.getLong(SHARED_PREFS_BATTERY_OPTIMIZATIONS_REMIND_TIME, BATTERY_OPTIMIZATIONS_REMIND_TIME_ALWAYS)
+    }
+
+    fun setBatteryOptimizationsRemindTime(timeMillis: Long) {
+        sharedPrefs.edit()
+            .putLong(SHARED_PREFS_BATTERY_OPTIMIZATIONS_REMIND_TIME, timeMillis)
+            .apply()
+    }
+
     fun getUnifiedPushEnabled(): Boolean {
         return sharedPrefs.getBoolean(SHARED_PREFS_UNIFIED_PUSH_ENABLED, true) // Enabled by default
     }
@@ -350,6 +360,7 @@ class Repository(private val sharedPrefs: SharedPreferences, private val subscri
         const val SHARED_PREFS_CONNECTION_PROTOCOL = "ConnectionProtocol"
         const val SHARED_PREFS_BROADCAST_ENABLED = "BroadcastEnabled"
         const val SHARED_PREFS_RECORD_LOGS_ENABLED = "RecordLogs"
+        const val SHARED_PREFS_BATTERY_OPTIMIZATIONS_REMIND_TIME = "BatteryOptimizationsRemindTime"
         const val SHARED_PREFS_UNIFIED_PUSH_ENABLED = "UnifiedPushEnabled"
         const val SHARED_PREFS_UNIFIED_PUSH_BASE_URL = "UnifiedPushBaseURL"
 
@@ -360,6 +371,9 @@ class Repository(private val sharedPrefs: SharedPreferences, private val subscri
         const val CONNECTION_PROTOCOL_JSONHTTP = "jsonhttp"
         const val CONNECTION_PROTOCOL_WS = "ws"
 
+        const val BATTERY_OPTIMIZATIONS_REMIND_TIME_ALWAYS = 1L
+        const val BATTERY_OPTIMIZATIONS_REMIND_TIME_NEVER = Long.MAX_VALUE
+
         private const val TAG = "NtfyRepository"
         private var instance: Repository? = null
 
diff --git a/app/src/main/java/io/heckel/ntfy/ui/MainActivity.kt b/app/src/main/java/io/heckel/ntfy/ui/MainActivity.kt
index 7d43540..5666012 100644
--- a/app/src/main/java/io/heckel/ntfy/ui/MainActivity.kt
+++ b/app/src/main/java/io/heckel/ntfy/ui/MainActivity.kt
@@ -5,11 +5,14 @@ import android.animation.AnimatorListenerAdapter
 import android.app.AlertDialog
 import android.content.Intent
 import android.net.Uri
+import android.os.Build
 import android.os.Bundle
+import android.provider.Settings
 import android.view.ActionMode
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
+import android.widget.Button
 import android.widget.Toast
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
@@ -20,6 +23,7 @@ import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
 import androidx.work.*
 import io.heckel.ntfy.R
 import io.heckel.ntfy.app.Application
+import io.heckel.ntfy.db.Repository
 import io.heckel.ntfy.db.Subscription
 import io.heckel.ntfy.firebase.FirebaseMessenger
 import io.heckel.ntfy.log.Log
@@ -27,10 +31,7 @@ import io.heckel.ntfy.msg.ApiService
 import io.heckel.ntfy.msg.NotificationDispatcher
 import io.heckel.ntfy.service.SubscriberService
 import io.heckel.ntfy.service.SubscriberServiceManager
-import io.heckel.ntfy.util.fadeStatusBarColor
-import io.heckel.ntfy.util.formatDateShort
-import io.heckel.ntfy.util.shortUrl
-import io.heckel.ntfy.util.topicShortUrl
+import io.heckel.ntfy.util.*
 import io.heckel.ntfy.work.PollWorker
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
@@ -120,6 +121,34 @@ class MainActivity : AppCompatActivity(), ActionMode.Callback, AddFragment.Subsc
             SubscriberServiceManager.refresh(this)
         }
 
+        // Battery banner
+        val batteryRemindTimeReached = repository.getBatteryOptimizationsRemindTime() < System.currentTimeMillis()
+        val ignoringBatteryOptimizations = isIgnoringBatteryOptimizations(this)
+        val showBatteryBanner = batteryRemindTimeReached && !ignoringBatteryOptimizations
+        val batteryBanner = findViewById<View>(R.id.main_banner_battery)
+        batteryBanner.visibility = if (showBatteryBanner) View.VISIBLE else View.GONE
+        Log.d(TAG, "Battery: ignoring optimizations = $ignoringBatteryOptimizations (we want this to be true); remind time reached = $batteryRemindTimeReached")
+        if (showBatteryBanner) {
+            val dismissButton = findViewById<Button>(R.id.main_banner_battery_dismiss)
+            val askLaterButton = findViewById<Button>(R.id.main_banner_battery_ask_later)
+            val fixNowButton = findViewById<Button>(R.id.main_banner_battery_fix_now)
+            dismissButton.setOnClickListener {
+                batteryBanner.visibility = View.GONE
+                repository.setBatteryOptimizationsRemindTime(Repository.BATTERY_OPTIMIZATIONS_REMIND_TIME_NEVER)
+            }
+            askLaterButton.setOnClickListener {
+                batteryBanner.visibility = View.GONE
+                repository.setBatteryOptimizationsRemindTime(System.currentTimeMillis() + ONE_DAY_MILLIS)
+            }
+            fixNowButton.setOnClickListener {
+                batteryBanner.visibility = View.GONE
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                    val intent = Intent(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS)
+                    startActivity(intent)
+                }
+            }
+        }
+
         // Create notification channels right away, so we can configure them immediately after installing the app
         dispatcher?.init()
 
@@ -535,6 +564,7 @@ class MainActivity : AppCompatActivity(), ActionMode.Callback, AddFragment.Subsc
         const val EXTRA_SUBSCRIPTION_INSTANT = "subscriptionInstant"
         const val EXTRA_SUBSCRIPTION_MUTED_UNTIL = "subscriptionMutedUntil"
         const val ANIMATION_DURATION = 80L
+        const val ONE_DAY_MILLIS = 86400000L
 
         // As per documentation: The minimum repeat interval that can be defined is 15 minutes
         // (same as the JobScheduler API), but in practice 15 doesn't work. Using 16 here.
diff --git a/app/src/main/java/io/heckel/ntfy/util/Util.kt b/app/src/main/java/io/heckel/ntfy/util/Util.kt
index 8949c7e..779e7f8 100644
--- a/app/src/main/java/io/heckel/ntfy/util/Util.kt
+++ b/app/src/main/java/io/heckel/ntfy/util/Util.kt
@@ -3,9 +3,14 @@ package io.heckel.ntfy.util
 import android.animation.ArgbEvaluator
 import android.animation.ValueAnimator
 import android.content.Context
+import android.content.Intent
 import android.net.Uri
+import android.os.Build
+import android.os.PowerManager
 import android.provider.OpenableColumns
+import android.provider.Settings
 import android.view.Window
+import io.heckel.ntfy.R
 import io.heckel.ntfy.db.Notification
 import io.heckel.ntfy.db.Subscription
 import java.security.SecureRandom
@@ -185,3 +190,13 @@ fun supportedImage(mimeType: String?): Boolean {
     return listOf("image/jpeg", "image/png").contains(mimeType)
 }
 
+// Check if battery optimization is enabled, see https://stackoverflow.com/a/49098293/1440785
+fun isIgnoringBatteryOptimizations(context: Context): Boolean {
+    val powerManager = context.applicationContext.getSystemService(Context.POWER_SERVICE) as PowerManager
+    val appName = context.applicationContext.packageName
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+        return powerManager.isIgnoringBatteryOptimizations(appName)
+    }
+    return true
+}
+
diff --git a/app/src/main/res/drawable/ic_battery_alert_red_24dp.xml b/app/src/main/res/drawable/ic_battery_alert_red_24dp.xml
new file mode 100644
index 0000000..22b3e04
--- /dev/null
+++ b/app/src/main/res/drawable/ic_battery_alert_red_24dp.xml
@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:pathData="M15.67,4L14,4L14,2h-4v2L8.33,4C7.6,4 7,4.6 7,5.33v15.33C7,21.4 7.6,22 8.33,22h7.33c0.74,0 1.34,-0.6 1.34,-1.33L17,5.33C17,4.6 16.4,4 15.67,4zM13,18h-2v-2h2v2zM13,14h-2L11,9h2v5z"
+      android:fillColor="#F44336"/>
+</vector>
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 75fb54a..8ce5067 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,15 +1,91 @@
 <?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
                                                    xmlns:app="http://schemas.android.com/apk/res-auto"
-                                                   xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
+                                                   android:layout_width="match_parent"
                                                    android:layout_height="match_parent">
 
+    <com.google.android.material.card.MaterialCardView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:shapeAppearance="?shapeAppearanceLargeComponent" app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintEnd_toEndOf="parent" app:layout_constraintTop_toTopOf="parent"
+            android:id="@+id/main_banner_battery" android:visibility="visible">
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:id="@+id/main_banner_battery_constraint" android:elevation="5dp">
+
+            <ImageView
+                    android:layout_width="28dp"
+                    android:layout_height="28dp" app:srcCompat="@drawable/ic_battery_alert_red_24dp"
+                    android:id="@+id/main_banner_battery_image"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toTopOf="@+id/main_banner_battery_text"
+                    app:layout_constraintEnd_toStartOf="@id/main_banner_battery_text"
+                    app:layout_constraintBottom_toBottomOf="@+id/main_banner_battery_text"
+                    android:layout_marginStart="15dp"/>
+            <TextView
+                    android:id="@+id/main_banner_battery_text"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:text="@string/main_banner_battery_text"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintTop_toTopOf="parent"
+                    android:layout_marginEnd="15dp" android:layout_marginTop="15dp"
+                    app:layout_constraintStart_toEndOf="@+id/main_banner_battery_image"
+                    android:layout_marginStart="10dp"/>
+
+            <com.google.android.material.button.MaterialButton
+                    android:id="@+id/main_banner_battery_ask_later"
+                    style="@style/Widget.MaterialComponents.Button.TextButton"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="5dp"
+                    android:layout_marginEnd="5dp"
+                    android:text="@string/main_banner_battery_button_ask_later"
+                    app:layout_constraintBottom_toBottomOf="parent"
+                    app:layout_constraintEnd_toStartOf="@id/main_banner_battery_fix_now"
+                    app:layout_constraintTop_toBottomOf="@+id/main_banner_battery_text"
+                    android:layout_marginBottom="5dp"/>
+
+            <com.google.android.material.button.MaterialButton
+                    android:id="@+id/main_banner_battery_dismiss"
+                    style="@style/Widget.MaterialComponents.Button.TextButton"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="5dp"
+                    android:layout_marginEnd="5dp"
+                    android:text="@string/main_banner_battery_button_dismiss"
+                    app:layout_constraintBottom_toBottomOf="parent"
+                    app:layout_constraintEnd_toStartOf="@id/main_banner_battery_ask_later"
+                    app:layout_constraintTop_toBottomOf="@+id/main_banner_battery_text"
+                    android:layout_marginBottom="5dp"/>
+            <com.google.android.material.button.MaterialButton
+                    android:id="@+id/main_banner_battery_fix_now"
+                    style="@style/Widget.MaterialComponents.Button.TextButton"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="5dp"
+                    android:layout_marginEnd="15dp"
+                    android:text="@string/main_banner_battery_button_fix_now"
+                    app:layout_constraintBottom_toBottomOf="parent"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintTop_toBottomOf="@+id/main_banner_battery_text"
+                    android:layout_marginBottom="5dp"/>
+        </androidx.constraintlayout.widget.ConstraintLayout>
+    </com.google.android.material.card.MaterialCardView>
+
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
             android:id="@+id/main_subscriptions_list_container"
             android:layout_width="match_parent"
-            android:layout_height="match_parent"
+            android:layout_height="0dp"
             android:layout_marginTop="10dp"
-            android:visibility="gone">
+            android:visibility="visible"
+            app:layout_constraintStart_toStartOf="parent" app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/main_banner_battery">
         <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/main_subscriptions_list"
                 android:layout_width="match_parent"
@@ -19,13 +95,14 @@
                 android:background="?android:attr/selectableItemBackground"
                 app:layoutManager="LinearLayoutManager"/>
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
     <LinearLayout
             android:orientation="vertical"
             android:layout_width="match_parent"
             android:layout_height="wrap_content" app:layout_constraintTop_toTopOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintBottom_toTopOf="@+id/fab" app:layout_constraintStart_toStartOf="parent"
-            android:id="@+id/main_no_subscriptions">
+            android:id="@+id/main_no_subscriptions" android:visibility="gone">
         <ImageView
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content" app:srcCompat="@drawable/ic_sms_gray_48dp"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index c5d6e8d..e77d548 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -67,6 +67,12 @@
     </string>
     <string name="main_unified_push_toast">This subscription is managed by %1$s via UnifiedPush</string>
 
+    <!-- Main activity: Battery banner -->
+    <string name="main_banner_battery_text">Battery optimization should be disabled to avoid issues with notification delivery.</string>
+    <string name="main_banner_battery_button_ask_later">Ask later</string>
+    <string name="main_banner_battery_button_dismiss">Dismiss</string>
+    <string name="main_banner_battery_button_fix_now">Fix now</string>
+
     <!-- Add dialog -->
     <string name="add_dialog_title">Subscribe to topic</string>
     <string name="add_dialog_description_below">
diff --git a/assets/battery_alert_black_24dp.svg b/assets/battery_alert_black_24dp.svg
new file mode 100644
index 0000000..91dd61d
--- /dev/null
+++ b/assets/battery_alert_black_24dp.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 0 24 24" width="24px" fill="#000000"><path d="M0 0h24v24H0V0z" fill="none"/><path d="M15.67 4H14V2h-4v2H8.33C7.6 4 7 4.6 7 5.33v15.33C7 21.4 7.6 22 8.33 22h7.33c.74 0 1.34-.6 1.34-1.33V5.33C17 4.6 16.4 4 15.67 4zM13 18h-2v-2h2v2zm0-4h-2V9h2v5z"/></svg>
\ No newline at end of file