If you’ve ever found yourself glancing at your wrist and wondering how much longer your smartwatch will hang on, you’re definitely not alone.
For all the massive leaps forward we’ve seen from the best smartwatches in the past decade, from sleek designs to innovative health tracking, battery life remains the one thing that just can’t keep up.
Whether you’re team Apple, Samsung or something else entirely, the dream of a capable smartwatch that lasts more than a day or two feels just out of reach.
But things could soon change.
The latest Apple Watch offers the same battery life as the first
There’s no better example of stagnant battery life advancements in wearable technology than the Apple Watch. When the first Apple Watch hit the market back in 2015, Apple promised up to 18 hours of battery life. Just shy of a day, but hey, it’s a first-gen wearable in a burgeoning wearable market.
Fast forward a whopping 10 years to 2025, and Apple’s latest Apple Watch Series 10 offers the same 18-hour battery life promise. A whole 10 years, and not much to show for it in terms of battery longevity.
Granted, Apple does offer boosted battery life with the Apple Watch Ultra, but it’s much bulkier as a result – and not to mention much more expensive than the regular model.
I might be giving the Apple Watch a bit of a rough time, but honestly, things aren’t that much better on the Android side of things.
The Galaxy Watch 8 is a good example of this. The larger 44mm variant of Samsung’s latest wearable offers 30 hours of battery life with AOD on or 40 hours with it off. The first Samsung wearable – the Samsung Gear S, released in 2014 – offered even better battery life at 48 hours.
Regardless of the specifics, it seems that many smartwatches are still hovering at the same one-day use that they were over a decade ago.
Some wearables are breaking the mould
That said, there are some outliers in the smartwatch world that manage to offer solid multi-day battery life, even when running the battery-hungry Wear OS.
Take the OnePlus Watch 3 for example. The Watch 2 already boasted some of the best battery life around at four days in Wear OS mode and 12 days in its more efficient mode, but the Watch 3 smashes past that with five days and 16 days respectively.
I got the opportunity to speak to OnePlus about how it managed such an achievement when so much of the competition struggles, and it essentially boils down to the design of the internals.
Most wearables, including the Galaxy Watch series, run both the OS and sensors on the high-powered CPU, and this is taxing on battery life. The OnePlus Watch 3 changes things by sporting a dual-architecture design comprising a CPU and an MPU.
The idea is that fitness and health tracking sensors, and the associated data, are handled by the more power-efficient MPU, while the CPU focuses solely on running the OS itself.
OnePlus isn’t the only Wear OS-toting wearable with multi-day battery life either; the TicWatch Pro 5 boasts a solid three to four days of battery life, thanks to its large battery and dual-display tech.
Silicon-carbon battery tech could revolutionise the industry
Aside from adopting similar tactics to OnePlus’ dual-architecture strategy, wearable manufacturers could solve the issue of battery life by simply including larger cells.
Of course, that’s easier said than done when space is at such a premium on small devices like smartwatches, but that’s where the new silicon-carbon battery technology comes into play.
Compared to the lithium-ion battery tech that’s ubiquitous in modern tech, silicon-carbon batteries can pack higher capacities into smaller form factors. This essentially means that, even without expanding the physical size of the battery, you could see a big improvement in overall battery life.
It’s a transformation we’re already seeing in the smartphone industry. While 5000mAh was seemingly the ceiling for quite some time, we’ve started seeing high-capacity silicon-carbon alternatives like the 6000mAh OnePlus 13 appear in recent months. And as the OnePlus flagship shows, that extra 1000mAh can make all the difference, turning the phone into a two-day device.
Now, scale that down, and it seems like the perfect upgrade for wearable batteries, allowing manufacturers to boost capacity and, as a result, battery life without having to compromise by making thicker, heavier wearables.
It’s just a question of when smartwatch manufacturers will start utilising the tech.
The simple OS alternative
Of course, there is another alternative to solve the smartwatch battery life issue – and it’s something we’ve already seen from plenty of wearables.
Yes, I’m talking about proprietary, scaled-back operating systems like those found on wearables like the Garmin Enduro 3 and Huawei Watch GT 5 Pro – wearables that boast weeks, not days, of battery life on a single charge.
It seems the issue with premium wearables that run Apple’s watchOS and Google’s Wear OS is that they’re massively demanding in terms of processing power. Running third-party apps standalone on the watch, generating quick replies for incoming messages, allowing virtual assistants to listen out for wake words – these all demand a lot of power.
It turns out that, if you strip back the operating system to focus more on fitness tracking with more basic smartwatch features, you can get much more out of your smartwatch. The question is though, does that turn them into fitness trackers with watch-like form factors? I’ll let you ponder that one for a while.
