For as much as we've heard about the Apple Watch in the last month, we've heard almost nothing about the stuff that makes it (figuratively) tick. Apple mentioned the S1 "System in Package" back in September when it unveiled the watch, but the company has said almost nothing about it since, and we didn't know anything about battery capacity or the other components. Today, the teardown mages at iFixit have answered at least a few questions in their teardown of a 38 mm Apple Watch Sport, though concrete information about the S1's inner workings continues to elude us.

Some components were actually fairly easy to remove and replace. Though it's difficult to disconnect the display cable, the watch's screen comes off easily once you've heated the glue that holds it in place. The 205 mAh battery (around two-thirds to one-half the size of the batteries in Android Wear watches, which tend to run between 300 and 400 mAh) is easily lifted out and disconnected, since it's only held in place with light adhesive. The 42 mm model will have a slightly larger battery, but we don't know its exact capacity just yet.

Those components are the ones that will need to be replaced the most often, so it's good that they're pretty easy to get at. Unfortunately, the rest of the watch is harder to crack. The various cables, Taptic Engine, speaker, and buttons aren't too hard to remove aside from being tiny (and the fact that they're held in with minuscule tri-wing screws), but the S1 is a glued-in octopus of cables that's hard to remove without breaking stuff. Even once it was out, iFixit couldn't get a closer look at it—the silver cap isn't a heat spreader, but a "solid block of plasticky resin."

iFixit gives the Apple Watch a repairability score of 5 out of 10, lower than the iPhone 6 (7 out of 10) but higher than larger products like the iPad Air 2 (2 out of 10) or the Retina MacBook (1 out of 10). The band, screen, and battery are all reasonably easy to replace, but it's difficult-to-impossible to remove and replace virtually any other component. For more information, including more pictures and a look at the Apple Watch's charger, give the full teardown a read.