When we went hands-on with the iPhone XS and XS Max, we were mainly struck by how similar they felt to the iPhone X—particularly the iPhone XS. But it turns out that inside, it's the iPhone XS that diverges with an unusual new battery design. iFixit tore down both phones and provided analysis and gorgeous pictures as always. Be sure to check out their full teardown, but a few highlights stand out.

Let's be clear: both of these phones are the iPhone X in more ways than not. Last year brought that quasi-radical redesign of Apple's product, but what was quasi-radical in 2017 is standard in 2018. Most of the components in both phones are the same, or very close, to what we saw in the iPhone X . Small changes include an added antenna band on the bottom of each device near the Lightning port (which iFixit speculates has to do with Gigabit LTE), a 32 percent larger wide angle sensor and increased pixel size for the rear camera in both phones, and a larger taptic engine and extended logic board in the iPhone XS Max.

As noted, the really interesting change is in the iPhone XS' battery. Like the iPhone X, both new phones have an L-shaped recess to accommodate their batteries. But whereas the iPhone X had (and the iPhone XS Max still has) a double-battery configuration—one for the vertical line of the L and the other for the horizontal—the iPhone XS has one L-shaped battery. That shape isn't just unusual because it's an L; here's just a little bit of what iFixit said in a separate article about the battery:

The challenge with any lithium-polymer battery cell is that each corner needs to be sealed to prevent undue stress from thermal expansion—and since the battery of the XS has 6 sides vs. the traditional 4, those extra corners can be tricky. To reduce the stress on the corners, Apple notched the internal corner of the battery.

The iPhone XS' battery capacity is actually very slightly reduced compared to that of the iPhone X—2,659 mAh to the iPhone X's 2716 mAh—but the iPhone XS Max's battery is relatively beastly at 3,179 mAh, which makes sense given its significantly larger display. Apple claims slightly improved battery life in both phones over what we saw last year.

iFixit gave both phones a six repairability score out of 10, noting that critical display and battery repairs are still a priority in the design and that the display can be removed without removing the TrueDepth array. However, the bump to IP68 waterproofing makes repairs just a little more difficult, and the front and back are still made of big glass panels.

Look for our review of the iPhone XS and XS Max in the coming days.

Listing image by iFixit