Apple's new AirPods Max headphones cost an arm and a leg ($549 to be exact), but that money does not include a power button. Instead, the AirPods Max rely on a number of low-power modes to maintain the promised 20 hours of listening time.

Tests have already proven that battery life is reduced without docking the AirPods Max into the Smart Case, but now Apple has explained exactly how long it takes for the various power-saving modes to take effect.

According to Apple's official support page, there are three levels of power: the first, obviously, is when the headphones are actually in use. When the headphones are removed and placed in the Smart Case, the AirPods Max immediately enters a low-power mode, but if the over-ear headphones are placed and left stationary for five minutes, it apparently enters a low-power mode.

The real difference between putting the AirPods Max in and out of the Smart Case is the time it takes to enter the ultra-low power mode where both Bluetooth and the "Find My" location tracking feature are disabled. This mode is activated after 18 hours with the Smart Case in, but takes 72 hours without. If you lose your AirPods Max while out and about, it is possible that it was not in the Smart Case at the time.

While still not as flexible as a dedicated power button, it should help somewhat to reassure people that the AirPods Max are not needlessly draining their battery life; if they misplace the Smart Case, the headphones are completely out of battery. It is highly unlikely that the headphones will run out of battery completely if the Smart Case is left behind. Even if that were to happen, Apple says that the AirPods Max can provide 90 minutes of audio on a five-minute charge.

Still, some people might prefer to have a power button. If so, see our list of the best wireless headphones before entering your credit card details.