iFixit didn’t waste any time on a teardown of the iPhone 7 Plus, and has now done the same with the new Apple Watch Series 2.

The main discovery is a much higher-capacity battery. The 273mAh battery offers almost a third more capacity than the 205mAh one in the first-gen Watch. However, all that extra power doesn’t extend the battery-life of the device – it’s rated for the same 18 hours as the original – it instead powers the built-in GPS and much brighter screen.

iFixit also identified what seems to be the main secret to the greatly-improved waterproofing of the Series 2 …

As we pick up the display, we notice that the adhesive is much stronger than what we found in the 2015 model. We assume this change is for the purpose of added water resistance.

The main gasket is similar to the first-gen Watch, suggesting that it’s the adhesive which makes the biggest difference, though the company did find additional smaller gaskets and o-rings inside – and, of course, the speaker able to use sound to pump out water.

iFixit reports that new ‘zero insertion force’ connectors make the Watch more repairable than its predecessor, but that removing all the adhesive necessary to gain access will probably affect the waterproofing.

The Taptic Engine responsible for the haptic feedback is noticeably larger, and the antenna is a more complex assembly given the addition of the GPS. One thing that proved a surprise was a second microphone, most likely intended for noise-reduction to improve Siri reliability.

Check out the full set of photos over at iFixit.

Reviews of the Watch pretty consistently described the improvements as being all about fitness.