Apple Watch will feature 'all-day' battery life of 18 hours

The Apple Watch will need to be recharged nightly, as Apple revealed on Monday that its upcoming wearable accessory will offer an average of 18 hours of runtime on a single charge.

According to Apple, the Apple Watch will feature "18-hour all-day battery life," though the company admits in fine print that real-life battery life will depend on device settings, usage and other factors.

Users will recharge their Apple Watch nightly with a new charging cable utilizing MagSafe technology. The quick connection simply snaps into place and begins regenerating the battery.

Apple's tests show that 1.5 hours of charging will restore the battery to 80 percent, while 2.5 hours will completely fill it to 100 percent. The 42mm model typically experiences longer battery life.

Talk time is rated at up to 3 hours, workout tests up to 7 hours, audio playback up to 6.5 hours, and the special power reserve mode will operate up to 72 hours.

Spare chargers will cost $29 for the smaller 38-millimeter Apple Watch size, while the larger 42-millimeter variant will be accompanied by a $39 charging cable.

The cable will feature a circular MagSafe charger on one end, and a traditional USB port on the other.

Battery life of the Apple Watch was one of the biggest unknowns about the device after it was unveiled last year. The company laid out all of the final details on the device and its capabilities at a media event on Monday, where it also revealed that the Apple Watch will become available on April 24.

Users will be able to make reservations at Apple Stores to try out the new device two weeks earlier, on April 10. That same day, Apple will also begin taking Apple Watch preorders ahead of the launch.

The Apple Watch will start at $349 for the 38-millimeter Sport version, while the 42-millimeter size will be $399. The stainless steel version starts at $549/$599, while the 18-karat gold Edition will have limited availability and a $10,000 starting price.