The Apple Watch Ultra's battery life just blew me away — here's how long it lasted

Apple Watch Ultra
(Image credit: Future)

Battery life has never been a selling point of the Apple Watch; that is, until the Apple Watch Ultra. Promising up to 36 hours of battery life (before the new Apple Watch low power mode,) the rugged smartwatch doubled the stamina expectancy that existing Apple Watch users experience.

Not only am I one of those users, but as an adopter of the original Apple Watch, an 18-hour battery life has been my standard for several years. Charging my Apple Watch every day is as routine for me as brushing my teeth or drinking a cup of coffee. So I’m sure you could imagine the adjustments I had to make when I finally got the Apple Watch Ultra, the best Apple Watch ever terms of battery life, on my wrist.

Testing out the Apple Watch Ultra the past few days threw off my charging rhythm, so to speak. Starting with a full battery at 3 p.m. on Friday, my Apple Watch Ultra’s battery life was down to just 45% at 3 p.m. the following day. That was with sleep tracking overnight and 70 minutes of fitness tracking when I wore my Apple Watch for hot yoga on Saturday morning. 

Normally, I top off my Apple Watch's battery when I wake up before a workout, but I had no need to with the Apple Watch Ultra.

Apple Watch Ultra

My first workout wearing the Apple Watch Ultra was a 70-minute hot vinyasa. (Image credit: Future)

The Apple Watch Ultra then survived yet another night of sleep tracking. It wasn’t until I was on a 4-mile walk early Sunday morning that the battery life dropped below 15%. At that point, I turned on low power mode, which forced the smartwatch to ping my GPS and read my heart rate less frequently. I was on a flat and familiar neighborhood walk — not navigating nature trails — so the low power mode activity function didn’t deeply impact my exercise metrics. Better yet, I still managed to make progress on my Apple Watch rings.

The Apple Watch Ultra lasted nearly 48 hours with what I would consider normal use. This is more than double my battery life experience with the Apple Watch Series 8.

Somewhere between 1 p.m and 2 p.m. on Sunday, my Apple Watch Ultra finally ran out of juice. That means it lasted nearly 48 hours with what I would consider normal use. This is more than double my battery life experience with the Apple Watch Series 8 vs. Apple Watch Ultra. When I tested the Apple Watch Series 8 without low power mode, it lasted just about 24 hours, or a full day.

Apple estimates the Apple Watch Ultra can actually last up to 60 hours (or 2.5 days) leveraging low power mode properly, which seems like a revelation. I think if I forgot to pack a charger for a regular weekend trip, I could still rely on the Apple Watch Ultra to survive. And that’s incredible compared to what I’ve dealt with previously — I’ve lost count of how many times I lost my Fitness app award streaks because I left a charger behind by accident.

Now, I say things like “regular trip” and “normal use” to clarify that certain features will cause the Apple Watch Ultra’s battery life to drain more quickly. LTE connectivity cuts into battery life, with Apple’s battery life information page (opens in new tab) stating the Ultra’s 36-hour estimate includes 8 hours of LTE use, while the smartwatch can last up to 18 hours with continuous LTE use. Things like working out and using the Apple Watch Ultra to take long phone calls will also cut into battery life.

By comparison, many of the best Fitbit trackers and best Garmin watches I've tested have a battery life of a week or longer. That's to say I know the Apple Watch Ultra's longer battery life might not seem like a huge feat for marathon runners or others who have never had to charge their smartwatch every day.

But for me, who has charged an Apple Watch almost every single day since 2017, even while testing other fitness trackers or smartwatches, the Apple Watch Ultra is a game-changer. 

I think it'll take me a couple weeks to nail down new charging habits, finding the sweet spot of the smartwatch's stamina and my schedule's convenience. In the meantime, it's safe to say this is one of the key reasons I would recommend the Apple Watch Ultra to someone. Though it has a handful of other exciting differences, none might have as much of a daily impact as the battery life. 

Kate Kozuch is an editor at Tom’s Guide covering smartwatches, TVs and everything smart-home related. Kate also appears on Fox News to talk tech trends and runs the Tom's Guide TikTok account (opens in new tab), which you should be following. When she’s not filming tech videos, you can find her on an exercise bike, mastering the NYT Crossword or channeling her inner celebrity chef.