Macworld reported on October 13, 2026, that a one-day Macwelt test recorded about 0.190 watt-hours of energy use for Apple Watch Series 12 in a post-workout window, compared with about 0.248 Wh for Apple Watch Series 11. The Series 11 was paired with an iPhone and handled notifications and push alerts; the Series 12 was unpaired. The difference therefore does not isolate sensor use. Macworld’s account of the test does not give the test date.
What the one-day test measured
The watches accompanied a seven-hour hike. The first half was in power-saving mode and the second in normal workout mode. During the workout, both logged 900 seconds of background activity per 15-minute interval. The report says telemetry was collected every 15 minutes, with 60 data points covering 8 a.m. to 11 p.m. on the analyzed day.
Macworld also described more frequent health measurements on Series 12: daytime heart-rate readings every five seconds, compared with every five minutes previously, and heart-rate variability (HRV) readings every five minutes, compared with every two hours previously. HRV is a measure of variation in the time between heartbeats. NeoTeo has also covered the Series 12’s health data and Readiness setup in an earlier article.
The post-workout readings
From 5:30 p.m. to 11 p.m., the two watches recorded different levels of background activity and energy use:
| Measure, 5:30–11 p.m. | Apple Watch Series 11 | Apple Watch Series 12 |
| Background activity | 4,222 seconds | 4,883 seconds |
| Energy used | About 0.248 Wh | About 0.190 Wh |
| iPhone connection | Paired; handled notifications and push alerts | Unpaired |
The test author attributed the energy-use difference to heavier display activity on Series 11. The test units also had different battery readings: 1.403 Wh and 98% maximum capacity for Series 11, versus 1.461 Wh and 100% for Series 12. Macworld’s account cautioned that a one-day comparison cannot establish typical battery life, and the different pairing conditions further limit what the energy figures say about sensor use.
What two owner reports add
One Reddit user reported 65 hours of Series 12 use with Always-On Display off, two one-hour workouts, and sleep tracking each night. The user said Low Power Mode was not used until the battery fell below 10%. The individual report describes that person’s settings and use, not a standard runtime.
Another user reported 43 hours with 5% remaining after four 6-kilometer walks and two 60-minute strength workouts. The user also said they used Airplane Mode at night and had most notifications turned off. That account is a separate personal report; its workload and settings differ from the 65-hour account.
