Tim Cook alluded to a daily recharge for the Apple Watch when introducing the device and that’s looking more likely, according to 9to5Mac’s Mark Gurman. His sources say Apple originally planned for, and seems to be meeting, between 2.5 and 4 hours of active use on a single charge.
Clearly, there’s a limited amount of space for the watch battery, which is one part of the equation. Then there’s the parts that drain the battery such as the display and processor. Gurman reported that the custom chip inside the [company]Apple[/company] Watch — named the S1 — is akin to the company’s A5 processor used in the iPod touch and iPhone 4S. That should provide a solid balance between performance and battery life with a reported on-screen frame rate of 60fps.
How much of a balance? Here’s Gurman’s information on reported testing being done by Apple:
Our sources say that Apple is targeting 2.5 hours of “heavy” application use, such as processor-intensive gameplay, or 3.5 hours of standard app use. Interestingly, Apple expects to see better battery life when using the Watch’s fitness tracking software, which is targeted for nearly 4 hours of straight exercise tracking on a single charge.
I don’t quite get the gameplay reference — are you really going to play Flappy Birds on your wrist every day? — so it’s more likely a proxy for app usage. The fitness figure makes sense though since tracking sensors don’t require much power with the exception of a GPS radio. Instead, much of that battery drain is likely due to on-screen statistics such as steps taken, running distance and pace.
According to Gurman, Apple is shooting for 19 hours of mixed use for the first-generation Apple Watch which is on par with some of the currently available [company]Google[/company] Android Wear devices.
Others can go for up to two days on a charge with mixed usage but even these benefit from a nightly recharge. Since iPhone owners are the obvious target here — the Apple Watch will require an iPhone to work — and they’re already plugging in their handset each night already, I don’t think it will be an issue to charge the Apple Watch daily as well.