Apple Watch Ultra 3 Teardown: Battery Size and Case Hardness Confirmed

iFixit's teardown of the Apple Watch Ultra 3 has confirmed two things athletes actually care about: the battery is 6% larger than the Ultra 2, and the titanium case scores 6 on the Mohs hardness scale. That hardness rating puts it on par with most quality titanium sports watches, including the Garmin Fenix 8 Sapphire's titanium bezel, though sapphire crystal glass itself sits closer to 9 on the same scale.

The DLC (Diamond-Like Carbon) coating on the case adds a layer of scratch resistance on top of the base titanium hardness. This matters for trail runners and obstacle racers who drag their wrists across rocks, ropes, and rig bars. Coros Vertix 2S uses a similar DLC treatment, and field results there have been strong over 12-plus months of abuse.

The 3D-printed construction detail is worth flagging. Apple is using additive manufacturing to shape internal components, which allows tighter tolerances inside the case without adding weight. The Ultra 3 already sits at 61.4g, heavier than a Garmin Fenix 8 Solar titanium at 59g but lighter than the Polar Grit X2 Pro at 79g.

The 6% battery bump is modest. Ultra 2 delivered around 60 hours in standard GPS mode. A 6% gain gets you roughly 3 to 4 extra hours, pushing the ceiling toward 64 hours. That still trails the Coros Vertix 2S at 140 hours GPS or even the Garmin Fenix 8 at 90 hours in GPS mode.

Solid hardware upgrades, real durability credentials. But battery life remains the Ultra's weakest point against dedicated endurance watches.