The autonomy of the Apple Watch has always been debated. Personally, I’m one of those people who is satisfied as long as the watch lasts all day, because I can leave it charging overnight (I’m one of those people who doesn’t measure their sleep). Although I understand those who use it while sleeping because they need the maximum possible autonomy and also as fast a charge as possible.
To optimize this autonomy, Apple recently launched a low battery consumption mode for those who prefer it to the full performance of the Apple Watch and its sensors. So I did an experiment: live with this low-power mode permanently for a few days to see if I noticed a difference.
A saving mode Apple doesn’t want you to use all the time
Let’s put ourselves in a situation. My Apple Watch is a Series 4, a model that was released in fall 2018 but still works perfectly for me. I notice its age precisely in the battery: for some time I have been getting low battery warnings between 8:00 p.m. and 11:00 p.m. The watch He supports this day that I ask him and of which I have already spoken to you, but it begins to cost him
So one fine day, early in the morning, I turned on low battery mode to see what was going on. In theory, you can (more or less) double the battery life, so I thought maybe I could only charge the watch once every two days.
What I did concretely was turn on low power mode as soon as I put the watch on in the morning (something that could have been automated in some way), since when you put the watch on to charge it’s turned off . It shows that Apple doesn’t have the idea that you always have it active. On paper, this low power mode:
- Disable always-on display (I don’t have it on my model)
- Disable Abnormal Heart Rhythm Alerts
- Stop measuring my heart rate and blood oxygen in the background
- Stop offering to start a workout when it detects that I am exercising
- Stop Mirroring Phone Calls When iPhone Is Not By My Side
- Stop Using Wi-Fi or Bluetooth Connections When iPhone Is Away
It saves money, but it doesn’t work miracles with older models
At the interface level, you realize that you have activated low battery mode thanks to a small yellow circle that appears centered above the Apple Watch screen. In my daily tasks, I didn’t notice anything else, even though the heart rate measurements disappeared in the Health app. It’s a normal day:
And it’s a day with low power mode active. The only time my heart rate was measured was when I did a workout:
Normally my workouts don’t exceed forty minutes, I’m not a born athlete to say the least and I just try to maintain a healthy lifestyle. But while they last, Apple Watch’s sensors get to work.
During the rest of the day I didn’t notice any change either: I even continue to receive alerts to get up for a moment if I’ve been sitting for a long time. And although watchOS warns me that notifications may take a bit longer to come out, I haven’t noticed any issues in this regard. I always had my iPhone closed and notifications appeared instantly.
And autonomy? Well, in my particular case, I barely noticed any improvement. Whereas before I ended the days with a charge between 10% and 25%, the days when I was with the low battery consumption mode I encountered charges between 20% and 30%.
I don’t blame this on poor resource management by watchOS: I suspect my Apple Watch Series 4 battery is already deteriorating, so low power mode shouldn’t be able to draw much power additional. Which leads me to say that this low power mode not the best choice if the watch has a certain age and wear.
