https://www.tomsguide.com/news/airpods-max-most-confusing-feature-just-explained-by-apple

Apple’s new AirPod Max headphones may cost an arm and a leg (or, to be more accurate, $549) but that money doesn’t include a power button. Instead, the AirPods Max rely on a number of low-power modes to preserve their promised 20 hours’ of listening time.

Tests have already proven that you don’t need to dock the AirPods Max in their Smart Case to reduce the loss of battery life, but now Apple has explained exactly how long it takes for various power saving modes to kick in.

According to Apple’s official support page, there are three levels of power. The first, obviously, is when you’re actually using the headphones. If you take them off and pop them in the Smart Case, the AirPods Max will immediately enter low-power mode, but they’ll apparently also do this if you set the over-ear headphones down and leave them stationary for five minutes, which explains the minor difference in battery drain.

The real difference between the AirPods Max being in and out of the Smart Case is how long the headphones take to enter the ultra-low power saving state where both Bluetooth and the location tracking ‘Find My’ are disabled. This mode kicks in after 18 hours in the Smart Case, but will take 72 hours without, which kind of makes sense. If you lose your AirPods Max when out and about, it possibly won’t have been in its Smart Case at the time, and this gives you an extra couple of days to find your missing cans.

While it’s still not as flexible as a dedicated power button, this should go some way to reassuring people that the AirPods Max aren’t just needlessly dropping battery life. If you’ve misplaced your Smart Case, it’s pretty unlikely that your headphones will be completely drained of battery when you return to them. And even if you are in that situation, Apple says that five minutes of charging should give the AirPods Max enough juice of 90 minutes of audio, which isn’t too bad.

All the same, some would definitely prefer a power button. If that applies to you, be sure to consult our list of the best wireless headphones before typing in your credit card details.