Under the new terms of AppleCare+ for Apple Watch, iPhone and iPad plans, as noticed by MacRumors, if your Apple Watch battery retains less than 80% of its original capacity, you are eligible from today for a free repair or a replacement unit. The new terms are valid for AppleCare+ purchases made after April 9, 2015. Previously, Apple covered batteries that retained less than 50% of their original specifications. Those terms remain valid for purchases between September 9, 2013 and April 9, 2015.
Of course, you need to purchase an AppleCare+ plan to extend the warranty period of your Apple Watch, which, depending on your unit, will cost $65, $89, or $2,000 for the Apple Watch Sport, Apple Watch, and Apple Watch Edition, respectively.
Apple designed the Apple Watch with a goal of an 18-hour battery life after an overnight charge. That factors in mixed usage such as a 30-minute workout, checking time, receiving notifications, etc. Based on Apple’s tests, the 18-hour battery life allows 90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout, with music playback from Apple Watch via Bluetooth over the course of those 18 hours.
With Power Reserve on, the Apple Watch’s battery should last up to 72 hours – you can check the time for up to three days (this result is based on four time checks per hour).
Also, it is important to be aware that Apple designed the Apple Watch battery to retain up to 80% of its original capacity at 1000 complete charge cycles.
If you have issues with your Apple Watch battery and don’t have AppleCare+, an out-of-warranty battery service costs $99 (for every model). On the down side, there are out-of-warranty service fees, which are $299, $419, and $3,599 for the Sport, Watch, and Edition models, respectively.