Sources familiar with the Apple Watch’s development have revealed details on the specific battery life targets Apple is aiming to achieve with the new wearable device, with the company aiming for 19 hours of typical usage each day, 9to5Mac reports. Although Apple has previously indicated that the Apple Watch would need to be charged on a nightly basis, the new information suggests that Apple’s choice of CPU and screen for the Apple Watch will contribute to a significant power drain, with the Apple S1 chip used in the Watch performing “surprisingly close” to the A5 found in the iPod touch, and the Retina-class display capable of rendering graphics smoothly at 60 frames per second.
While Apple reportedly wanted the Watch battery to provide between 2.5 to 4 hours of active application use and 3 to 4 days of pure standby or sleeping time, sources indicate that the company will likely achieve only about 2 to 3 days of battery life while in the standby or low-power modes. Apple has also apparently been testing the Apple Watch’s battery life with various applications, and is targeting 2.5 hours of “heavy” app use or 3.5 hours of “standard” app use. Battery life while using fitness tracking software is expected to be better at up to 4 hours on a single charge. The company has also conducted numerous tests to determine how long the Apple Watch will run on a single charge in straight time-keeping modes, with information suggesting that clock face can be displayed for about three hours in total, including animations, although like the iPhone, the display will normally be powered off when the Watch screen is not actively in use.
The report’s sources indicate that Apple may not hit that 19-hour number in the first generation. Battery life has apparently remained the most serious concern for Apple over the Watch’s development cycle, and was at least part of the reason that the retail launch was pushed into 2015. The report notes that as many as 3,000 Apple Watch test units are currently deployed in order to test the device’s performance under real-world conditions.