Garmin Fenix 8 vs. Apple Watch Ultra 2: The Fenix wins big on battery life

Garmin's got a new flagship in its rugged smartwatch category, the Garmin Fenix 8.

The company's Fenix line of smartwatches has long been the golden standard for durable smartwatches for athletes, but Apple put up a pretty good fight with its Apple Watch Ultra (now on its second iteration) rugged smartwatch.

The list of specs on both these watches is incredibly long and includes support for a multitude of sports and outdoor activities, but we're going to focus on the most important bits here. You see, the Apple Watch Ultra 2 has always won on Apple's massive ecosystem of apps and the ability to make standalone calls, and integration with Apple's smart assistant, Siri. On the other hand, Garmin's Fenix watches were always far ahead when it comes to battery life, but the ability to make phone calls from the watch was absent. So how does the new Fenix 8 fit into this picture?

What's with the name?

Before we start, let's just clarify on Garmin's somewhat confusing new naming scheme. The company used to divide its flagship watch category into Fenix and Epix watches. Now, Epix is gone; instead, you have the Garmin Fenix 8 Solar, which essentially means "Fenix 8, with solar power, but without an AMOLED display." And then you have the Garmin Fenix 8, which has no solar power, but has an AMOLED display, which makes it a bit easier to read in direct sunlight.

The Fenix 8 also comes in several sizes, for a total of five variants. You can get the Fenix 8 Solar with a 47mm or 51mm display, while the Fenix 8 (with the AMOLED display but no solar) comes in 43mm, 47mm, or 51mm.

The Apple Watch Ultra 2 only comes in one size: 49mm, has no solar power, but it does have a very, very good OLED display.

Got all that? Great, let's continue.

Massive difference in battery life

This is Apple Watch Ultra 2's weak spot. It offers, per Apple's specs, up to 36 hours of battery life in normal use, and up to 72 hours in Low Power Mode. That's a lot better than the regular Apple Watch, but it lags far behind Garmin's best.

Garmin Fenix 8 offers a whopping 29 days of battery life, or 13 days with the always-on display option on. If you opt for the Fenix 8 Solar, this goes up to 30 days, or 48 days with solar charging (this assumes a lot of exposure to sunlight).

That's for the largest, 51mm variants of the Garmin. But even the smaller, 47mm version offers up to 16 days (7 days with always-on display on), or 21 days (28 days with solar charging). Finally, the 43mm version offers up to 10 days of battery life, (4 days with always-on display on).

This gets even more complicated when you add the various use cases and options that Garmin offers, such as Battery Saver mode, Expedition GPS mode, or Max Battery GPS mode. If you turn all satellite systems on and listen to music, for example, the battery life on the 51mm Fenix 8 goes down to 18 hours. Check out Garmin's spec sheet for all the details.

The bottom line, however, is that with the Garmin (per DC Rainmaker's incredibly thorough testing), will get you something like 6 days of regular use with some sports use thrown into the mix, while also giving you the option to extend that into weeks if needed.

Still no standalone calls

The Garmin Fenix 8 has another big addition: a microphone and speaker for calls, and invoking a personal assistant. You'd think that this makes it on par with the Apple Watch Ultra...but unfortunately it doesn't, because the Fenix 8, perplexingly, does not have cellular connectivity, so it relies on your phone to make calls.

Think about it: If you have a watch with a battery that lasts for days, and the ability to make calls, you'll be a little safer and more connected when you go for a long hike or other outdoorsy adventure. But if said watch relies on your phone to make calls, then you'll have to carry a phone and an additional battery with you, which sort of defeats the purpose of this feature.

As is, it's still a welcome improvement. With the new Garmin Fenix 8, you'll be able to answer that call mid-workout without reaching for your phone. But the Apple Watch Ultra 2, which has cellular connectivity, still wins in this regard.

Voice assistant, but basic

Similarly, the Garmin Fenix 8 now offers an offline Garmin voice assistant. This requires zero connectivity, which is nice, and it will let you perform basic tasks like start the timer, play some music, or start a workout. But that's pretty much as advanced as it gets.

Garmin also supports Apple's Siri, as well as Google and Samsung's voice assistant, but those work via your phone (depending on the model) aren't directly patched into Garmin's smarts, so you can't use them to control Garmin-specific features.

In contrast, Apple Watch Ultra 2 is well integrated with Apple's own voice assistant, Siri. Garmin is closing the gap a little bit here, and we haven't tested it ourselves yet, but it seems like Apple is ahead in this regard.

New diving features

When Apple launched its Ultra smartwatch, it did something interesting by adding well thought out support for recreational diving features. Typically, pro divers will want to use a dedicated diving computer (Garmin sells those as well), but Apple Watch Ultra 2 has a nice set of features that will satisfy most recreational divers.

Now, Garmin Fenix 8 supports diving-related features as well -- and yes, it does seem like Garmin had its mind on the Apple Watch Ultra 2 when it designed the new Fenix.

On the hardware level, the Fenix 8 now has a depth gauge and leak-proof metal buttons (the Ultra 2 doesn't have these). But it goes further than that, essentially adding a ton of functionality from its pro-grade Descent lineup of diving watches. In short, it supports scuba and apnea dive activities, and overall matches the Apple Watch Ultra's diving features. It's very close to a tie between the Fenix 8 and the Ultra 2, though Garmin's pro-diving pedigree does give a slight nod to the Fenix 8.

About that price

We've got bad news here. Garmin Fenix 8 starts $999.99, and that's for the 43mm AMOLED model. The 47mm variant (both Solar and AMOLED) costs $1,099.99, and the largest, 51mm version costs $1,199.99.

This is pricier than the Garmin Fenix 7 at launch and, more importantly, a lot more expensive than the $799 Apple Watch Ultra 2. Apple products aren't cheap, and when you're selling a competing product at this much of a premium, it's a pretty big statement -- or a mistake.

Is the Garmin Fenix 8 better than Apple Watch Ultra? Yes and no.

Garmin had an obvious intention to catch up with the Apple Watch Ultra 2 in all areas where it lagged behind, while improving even further in the battery life department.

And yeah, at a glance, the improvement do sound like the Fenix 8's got everything the Ultra 2 has (sans Apple's app ecosystem), while also offering massively better battery life and more versatile battery management.

However, the Fenix 8 still doesn't offer cellular connectivity, which is a bit of a bummer, and its voice assistant isn't as smart as Siri. It also costs a lot more than the Apple Watch Ultra 2. Also, the Ultra 2 might very soon get replaced with a new version, so we'd advice to wait until Apple's September 9 event until deciding on either model.