Charge it on a schedule, two short top-ups at fixed times. Then turn off Always On, stop mirroring every iPhone alert, use Low Power Mode on flights and check battery health.
Charge your Apple Watch on a schedule: two short top-ups at the same times every day, so it never dies mid-afternoon and is still on your wrist at night. Then turn off Always On, stop mirroring every iPhone alert to your wrist, and use Low Power Mode on flights.
I’ve worn a used Apple Watch Ultra (1st gen) every day for 10 months. Apple rates it at up to 36 hours. In my use it needs a charge while I shower and another before bed. Settings help, but the schedule is what keeps it going through a 15-hour day.
How I put this together
My own routine comes from 10 months on the Ultra, covered in my full review. For the settings, I used three videos: Tom’s Guide’s February 2026 battery-saving walkthrough, Brandon Butch’s October 2025 setup guide for the Series 11 and his June 2026 rundown of watchOS 27. I checked rated battery numbers against Apple’s spec pages. Menu paths below are on the watch unless I say otherwise. My Ultra runs watchOS 26.6, because Apple left it off watchOS 27. Every setting here works on both versions unless noted.
The settings at a glance
| Change | Where | What it saves | What you give up |
|---|---|---|---|
| Two fixed top-ups a day | Your routine | A dead watch at 4 p.m. | Two short breaks from wearing it |
| Always On off | Settings > Display & Brightness > Always On | About 15–20% in Tom’s Guide’s use | A dark screen until you raise your wrist |
| Fewer mirrored alerts | iPhone Watch app > Notifications | Screen-ons and vibrations | Some alerts stay on the phone |
| Low Power Mode on flights | Control Center > battery percentage | Hours, depending on the model | Background heart rate, Always On |
| Hey Siri off | Settings > Siri > Listen For | An always-listening mic | Hands-free Siri |
| Battery health check | Settings > Battery > Battery Health | Tells you if settings can still help | Nothing |
1. Fix the charging schedule first
Most battery advice starts with settings. I’d start with the charger, because no setting turns a 36-hour rating into two days of real use with sleep tracking.
My routine: the watch goes on the charger while I shower in the morning, and again for a bit before bed while I watch a show. That covers a long day of calls, Apple Pay and Mac unlocking, and it keeps the watch on overnight. If you want sleep data, that second top-up matters. A watch that dies at 3 a.m. records nothing.
Turn on Charging Reminders under Settings > Sleep. Brandon Butch recommends it, and it’s the setting that saves you from going to bed at 15%. Then build the habit around something you already do every day.
Newer watches make the schedule easier. Apple rates the Series 12 at 24 hours, and 15 minutes on the charger now adds up to 12 hours, per Brandon Butch’s Series 12 coverage. My Apple Watch buying guide compares battery across this year’s models.
2. Turn off Always On
On the watch, go to Settings > Display & Brightness > Always On and switch it off. Leave Raise to Wake on, so the screen lights up when you look at it. The Tom’s Guide reviewer saw about 15% to 20% more battery after turning Always On off.
If you’d rather keep it, there’s a middle option. In the iPhone Watch app, under Display & Brightness, you can keep Always On but hide complications, apps and Live Activities until you wake the screen.
One setting to leave alone: Brandon Butch suggests raising Wake Duration from 15 to 70 seconds so the watch locks less often. That’s handy, but it keeps the screen on longer every time. If battery is the problem, keep the default.
3. Cut the alerts that reach your wrist
Every notification wakes the screen and fires the haptic engine. Tom’s Guide calls the haptics a “sneaky” drain. Fewer alerts means more battery and fewer interruptions.
Open the Watch app on your iPhone, tap Notifications, and under Mirror iPhone Alerts From, switch off every app you don’t need on your wrist. Brandon Butch’s examples are Reddit, a to-do app and the TV app. Keep the ones you act on from your wrist, like calendar and messages. Everything else can wait for the phone.
This also fixes a work problem. On calls with no Focus mode on, notifications distract me. Set a Work Focus on the iPhone and it carries over to the watch. Under iPhone Settings > Focus, you can also link a specific watch face to that Focus. Brandon Butch suggests a dimmer face for sleep and different faces for work and workouts.
Silent Mode (Settings > Sounds & Haptics) helps too. With sound off, alerts come in as a tap on the wrist, and the morning alarm becomes a vibration that won’t wake anyone next to you.
4. Use Low Power Mode on flights
Open Control Center with the side button, tap the battery percentage and turn on Low Power Mode. You can leave it on indefinitely or set a time limit.
It turns off background heart rate readings and Always On, among other features. Tom’s Guide suggests it whenever you’re on a plane or sitting still. I agree. On a 10-hour flight you don’t need background heart rate, and you land with a watch that still works. Apple rates my Ultra at 36 hours normally and up to 60 in Low Power Mode. Tom’s Guide says the Ultra 3 gets close to double its battery life in this mode.
5. Turn off Hey Siri if you never use it
Go to Settings > Siri > Listen For and choose Off. Tom’s Guide turned it off because it rarely used Siri and didn’t want the mic listening all day. You can still raise your wrist or hold the Digital Crown to talk to Siri.
Keep it on if you’ll use Siri AI on watchOS 27. Brandon Butch says it’s planned for the watch, though it wasn’t in the first beta he tested.
6. Check battery health before you blame the settings
Go to Settings > Battery > Battery Health. Apple recommends a battery replacement once health drops below 80%, and Tom’s Guide notes that AppleCare covers that replacement. Below 80%, no setting in this guide will get you through a day.
Mine reads 88%. Some of my two-charges-a-day routine may be the battery’s age. I can’t tell you how much. My AppleCare is still active, which covers that replacement when the time comes.
Also check Optimized Battery Charging on the same screen. It holds the charge at 75% to 80% based on your daily routine, which helps the battery age more slowly. Before a long travel day, tap the green charging symbol and choose Charge to Full Now.
What watchOS 27 changes
Apple says watchOS 27 is more battery-efficient and will suggest battery optimizations across the system. Brandon Butch notes Apple didn’t say where those suggestions show up, and his video doesn’t measure the gain. The change I’d use daily is in notifications. Open one, tap the mute icon in the corner, and you can mute that app for an hour, send it to the summary or turn it off. That makes step 3 a one-tap job.
None of this reaches the first-generation Ultra. If you want watchOS 27’s features, my Ultra review explains why I’d point you to an Ultra 2 or an SE 3.
What I’d leave on
Tom’s Guide also suggests turning off heart rate monitoring. I wouldn’t. I check my heart rate often, and heart rate feeds your sleep and activity data. Use Low Power Mode on travel days instead, which pauses background readings only while it’s on.
My recommendation
Set the charging schedule first: one top-up in the morning, one before bed, with Charging Reminders on. Then turn off Always On and trim your mirrored alerts in the iPhone Watch app. That’s five minutes of setup. Use Low Power Mode when you fly, and check battery health once. If it’s under 80%, replace the battery before you change anything else.
FAQ
How long should an Apple Watch battery last?
Apple rates the SE 3 at 18 hours, the Series 12 at 24, the first-generation Ultra at 36 and the Ultra 4 at 50. My Ultra, at 88% battery health, needs two top-ups to cover a long day and a night of sleep tracking.
Does turning off Always On save battery?
Yes. The Tom’s Guide reviewer measured about 15% to 20% more battery life with it off. Leave Raise to Wake on so the screen still lights up when you look at it.
When should I charge my Apple Watch if I track sleep?
Top it up twice: once in the morning, for example while you shower, and once before bed. Turn on Charging Reminders under Settings > Sleep so it warns you when the battery is too low for the night.
What does Low Power Mode turn off on an Apple Watch?
Background heart rate readings and Always On, among other features. It’s worth turning on for flights and long days away from a charger.
When does an Apple Watch battery need replacing?
Apple recommends a replacement when Battery Health drops below 80%. You’ll find it under Settings > Battery > Battery Health. AppleCare covers the replacement.