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iFixit has completed a teardown of the Apple Watch Series 4, providing a look inside a larger 44mm model with LTE.

ifixit-apple-watch-series-4-teardown-1.jpg
Image Credit: iFixit

The repair experts believe that while the original Apple Watch was awkwardly layered together and used too much glue, the Series 4 lineup feels "much more thoughtfully laid out," likening it to the iPhone 5.
Apple pundit John Gruber has compared this to the leap in design brought by the iPhone 4, and we might even go a bit further and call it an iPhone 5: a device that knows its priorities, and wants to look as elegant inside as out.
At first glance, the internal design of Series 4 models looks more or less the same as previous models, with the battery and Taptic Engine taking up most of the space. Dig deeper, however, and the changes become evident.

ifixit-apple-watch-series-4-teardown-3.jpg
Image Credit: iFixit

Teardown highlights:1.12Wh battery in the 44mm model, which is 20% less capacity than the 1.34Wh battery in 42mm-sized Apple Watch Series 3 models.
A thinner and longer Taptic Engine, but iFixit says it still takes up a lot of space that could have gone to a larger battery.
The barometric sensor may have been relocated to the speaker grille for access to the outside atmosphere. The sensor had its own dedicated hole beside the microphone on Apple Watch Series 3 models.
The new Apple S4 chip is secured only with screws, whereas the processor is also "fiercely glued" in previous Apple Watch models.
The golden ring is likely a streamlined antenna system, as iFixit says it has not seen the usual fiddly brackets or golden gaskets.
The entire rear casing pops off more easily.
The display is not only larger, but also thinner.iFixit says the Apple Watch Series 4 is nearing iPhone levels of repairability, with the highly-glued display being the primary remaining obstacle. Beyond that, they say the battery is straightforward to replace.

ifixit-apple-watch-series-4-teardown-2.jpg
Image Credit: iFixit

All in all, the Series 4 received a "solid" 6/10 on iFixit's repairability scale, with 10 being the best possible score. That's the same repairability score iFixit gave the iPhone XS and XS Max in its teardown of those devices.

Update: A previous version of this article said Apple Watch Series 4 models have 4% more battery capacity, as iFixit mentioned, but that was based on comparing a 44mm Series 4 model with a 38mm Series 3 model. 44mm and 40mm Series 4 models actually have 20% less battery capacity compared to 42mm and 38mm Series 3 models respectively, although Apple says battery life remains up to 18 hours.

Article Link: Apple Watch Series 4 Teardown: 20% Less Battery Capacity, Hidden Barometric Sensor, and Streamlined Internals [Updated]
 

Eriamjh1138@DAN

macrumors 6502a
Sep 16, 2007
672
499
BFE, MI
If the watch is waterproof and dustproof how does air pressure get to the barometer?
The barometer senses pressure, not dust and water. iFixit says they put it behind the speaker, open to the air.
The sensor is waterproof and dustproof. It means it is not damaged by water and dust. It doesn't mean it doesn't get wet or dusty.
 

manu chao

macrumors 604
Jul 30, 2003
7,172
2,993
If the watch is waterproof and dustproof how does air pressure get to the barometer?
How can diving watches have pressure sensors? I don't know if all (air/water) pressure sensors are built this way but just imagine an impermeable membrane that is exposed to the outside via an open channel. Works like a plastic bottle that gets squeezed when the ambient pressure increases (eg, descending from high altitude). The fluid inside the bottle is still perfectly contained.
 

manu chao

macrumors 604
Jul 30, 2003
7,172
2,993
There is no such thing as waterproof, just water resistant.
Of course there is waterproof. Anything made out of materials that contact with water doesn't affect is waterproof. The spoon I am currently holding is waterproof. Anything completely encased in material that isn't affected by water is waterproof. Encase something in (originally molten) glas and it is waterproof. With the right glue, you can waterproof a lot of things.

One can distinguish between seals that can be opened and closed and something that is sealed by filling a gap with a material that is liquid originally and thus can enter all nooks and crannies. In particular with water, due to its surface tension, if a capillary connecting the inside with the outside becomes small enough, it is hermetically sealed (of the course the surface tension translates into capillary pressure which then has to be compared to the ambient pressure, but if we limit ourselves with ambient pressures a human can survive in that is a very attainable limit).
 

usarioclave

macrumors 65816
Sep 26, 2003
1,447
1,506
The barometer senses pressure, not dust and water. iFixit says they put it behind the speaker, open to the air.
The sensor is waterproof and dustproof. It means it is not damaged by water and dust. It doesn't mean it doesn't get wet or dusty.

I know what a barometer measures. That means that they're calibrating it to the internal pressure with the speaker, then the speaker cone will change the air pressure inside the watch (what the barometer is measuring).

However, that implies that the barometer readings will change when the speaker is in-use, which means they're doing some kind of compensation for speaker usage vis-a-vis the barometer.
 

iLoveDeveloping

macrumors 6502
Sep 24, 2009
472
1,410
Ireland
On a side note, anyone know how the ECG actually works yet? Is it sending a current around your body (like weighting scales for body composition) or is it totally passive just sensing a closed circuit of electrical heart rhythm? Anyone?

I’m not asking opinions I’m genuinely looking for the data on this? Seems like Apple explain their tech less and less these days.
 

Elijen

macrumors 6502
May 8, 2012
453
879
How can a small watch where every mm matters get 6/10 and a laptop 1/10 on repairability score? Apple pleaseeeee
 
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