Apple Watch battery

Do Apple Watch owners suffer “range anxiety”, in the same manner as electric car owners? In my experience, yes, but it fades quite quickly once expectations and experience collide and settle down.

For my usage so far – albeit just a week and a half – my 42mm watch generally has more than 50% left when I hit the sack, having been on my wrist approx 06:45 to 23:00. Given that I have no qualms at all about charging it every night, that’s pretty good, and better than a lot of scare stories had led me to expect. Of course if I was going camping for a week it would be utterly useless, but I accept that it’s just not the right product for that scene.

How much do I really use it though? I don’t stare at it all day long, especially as the novelty starts to wear off. Apple are correct: its rightful place in the world is for fleeting interactions lasting just a few seconds, and I have quickly settled into that very casual relationship with it. Right now, I use it to:

  • check the time (obviously)
  • check the weather
  • to see what song is playing on my iPhone when I don’t recognise it
  • to see incoming messages and tweets (but very rarely to respond to them)
  • to snooze/dismiss calendar alerts
  • to quickly set a timer for an ad-hoc reminder
  • to take incoming calls, before getting my iPhone out and switching to that – but I hope to get out of that habit
  • for running (much more about that in a future post)
  • for keeping tabs on general activity via Apple’s ‘Activity’ app with its all-knowing three circles

I’ve had one day where the battery ran out prematurely. Very prematurely, at 1830! That morning I’d gone for a 5km run using Apple’s built-in ‘Workout’ app – my first and only time with that app so far – which had knocked the battery down to 84% by 0700. That actually didn’t seem too bad for the run itself, since it was working hard keeping track of heart rate etc. but I still don’t understand how it came to expire later on, from being a mere 16% down at the start. Perhaps the battery level reporting was poor and when it said 84% it was actually much lower. Indeed when it flaked out, it was reporting 13% so maybe calibration was poor, and maybe I’m closer to the wire than I think when I go to bed with an apparently healthy percentage left. We’ll see how future experiments pan out.


The allure of being able to walk into an Apple Store, try one on and get instant purchasing gratification was just too much, and I caved. Having decided to get an Apple Watch to develop apps against, but never having actually liked the look of them, my opinion changed the moment I fondled one in the store. The quality feel is simply exceptional and it was immediately comfortable on my wrist, but the best and most surprising thing was the size.

I don’t have large wrists but the larger 42mm watch sits very nicely indeed. It is definitively not a hefty lump of technology struggling to masquerade as a watch. And I say that because I had expected it to be ungainly and oversized, based on my limited experience of Android devices.

But how have they achieved this? Wonders of electronic miniaturisation of course, with miserly power consumption allowing for a tinier battery than the competition. But that’s not the most cunning part in my opinion.

The crucial trick was to employ a rectangular screen and a user interface with a black background. This affords many subtle wins over much of the competition!

Rectangular screen

Many Android watches have gone for a circular screen – which best mirrors the classic round watch look. But it’s hard to use the circular space efficiently for displaying information other than a clock face. Apple’s rectangular screen is (comparatively) easy to fill up with well-spaced information, even though it’s tiny. To show a block of text on a circular screen means lots of wasted curved scraps of space. As a developer I’m glad I don’t have to create apps for circular screens!

Black background – black bezel

The Apple Watch user interface employs a black background throughout, which merges seamlessly into the black bezel around the screen, with the glass wrapping over both. The shine of the curved glass edge and the super-deep black of the OLED screen means it really is an invisible transition. This means that the user interface elements can run right out to the edges and corners of the screen, without requiring any padding to space them pleasingly away from those edges. The physical bezel outside the screen is that padding.

Again, this maximises the usable space whilst keeping the package small. Competing watches that have a distinct bezel have to inset UI elements and so a surprising amount of power-draining screen real-estate is wasted.

Also, with an OLED screen, a black background is directly better for power consumption, as each pixel is individually illuminated (there is no separate backlight) and black pixels consume the least power.

UI tricks to maintain the illusion

The ‘home screen’ is a hexagonal grid of circular icons, which immediately diffuses the rectilinear reality. The most cunning part of all though is how the icons smoothly shrink down to nothing as they approach the physical limits of the screen. This stops them being chopped off at the straight edge and so maintains the inky black illusion.


Elsewhere in the user interface, elements with non-black backgrounds are heavily rounded. Of course the screen edges reveal themselves when scrolling vertically through content, or sideways between glances, but those are usually fairly brief transitions, and the illusion can only go so far.

Bonus: no lugs

Unrelated to the points above, but worth mentioning for its vital impact on the sense of size, the strap connects to the case seamlessly via Apple’s custom attachment (all the better to sell you expensive replacements) but this negates the need for two lugs top and bottom, sticking out and increasing the height of the device.

Finally, some amateur prognostication

As smart phones evolved it turned out that telephony was way down on the list of real users’ activities. There will probably be a similar story with ‘smart watches’, with years of exciting evolution ahead, not just for the raw technology but to establish a successful form and function. It’s anthropology as much as it is technology. People’s habits and expectations, and fashion too will evolve alongside the gadgets.

Right now many vendors are trying to replicate the traditional watch in form, it being the obvious starting point, but I predict that we’ll quickly move on from that as people get used to having their digital lives reflected in miniature on their wrists. One of the clock faces that Apple provides is named “Modular”  – shown in the image at the top of this post – and is a very utilitarian grid of configurable information. At first I didn’t like it, but already it has won me over and I find it striking how far I’ve already been moved away from the traditional watch. Once again, the rectangular format plays well to this direction.

On the fashion front, I notice in the mirror that the Apple Watch on my wrist is a featureless, glossy black blob on a black strap when it’s not illuminated. This is quite a departure from the aesthetic of a traditional watch, and right now I’m not especially keen on it. But before long that will be an accepted norm that doesn’t seem strange or out of place.

Who knows – maybe my thoughts here are completely out of whack with what Apple were thinking. It’ll be interesting to see how things develop.