My M2 MBA now has got terrible battery life

[Aure1]

Hi everyone

I'm not used to using these forums so I apologize if this question is not at the right place.


I've had a base M2 Macbook Air, bought late 2022, with which I've been more than happy.

Lately though, my battery life has gone down to... 6 hours on a full charge.
Battery health reports 89%.
Activity Monitor doesn't reveal anything special.
Standby battery life still holds perfectly
My usage is very light, a few (20?) Safari tabs open, a whole lot of Youtube, and coding in iTerm2 + Neovim, a few ssh sessions.


I'm probably going to do a fresh install with MacOS26 coming very soon. Maybe I've got a rogue little pluggin pumping battery unnoticed ?


But before doing so, I wanted to ask opinions on wether this battery life after 2-3 years seemed reasonnable or not ?

It's really a bummer that I don't have all day battery life anymore, because I got used to leave the house without any cables or charger, that was neat.


Thanks for your input 😊

 

[IJustWannaTalk]

What's going on this those 20 (few? really?) tabs you have open?

 

[!!!]

Is YouTube streaming AV1 to you? If so, the M2 does not have a decoder for it, so it will use the CPU and drain more battery life. There are extensions for Firefox/Chrome which will prevent them from streaming AV1, I don't know about Safari.

Activity Monitor doesn't reveal anything special.

Are you sure? Did you check under the Energy tab?

 

[doyleo]

Your original post didn’t say, but have you done a complete shut down and restart? Don’t just put it to sleep. A shutdown, wait 30m seconds, and restart is always my first response when something changes in the way my computer is running.

 

[SmOgER]

Is YouTube streaming AV1 to you? If so, the M2 does not have a decoder for it, so it will use the CPU and drain more battery life. There are extensions for Firefox/Chrome which will prevent them from streaming AV1, I don't know about Safari.

Are you sure? Did you check under the Energy tab?

Interesting... Safari does have these feature flags:

 

[!!!]

Interesting... Safari does have these feature flags:

View attachment 2561959

Those are special APIs that websites can use, it's not going to affect YouTube's video playback. Recent versions of MacOS and most browsers will be able to play back av1 videos in software. Which consumes more CPU/battery life than hardware decoding of e.g. AVC(h.264), or VP9.

 

[vanc]

Those are special APIs that websites can use, it's not going to affect YouTube's video playback. Recent versions of MacOS and most browsers will be able to play back av1 videos in software. Which consumes more CPU/battery life than hardware decoding of e.g. AVC(h.264), or VP9.

Perhaps Youtube changed policy again? Tried a few 1080p and 4K videos in both Safari and Chrome on my MBP 14 with M4 max, the codec was VP9. Here is one example.

But for 8K videos, such as the 8K New York demo, the codec is in AV1. I was playing the 4K version.

 

[icymountain]

But before doing so, I wanted to ask opinions on wether this battery life after 2-3 years seemed reasonnable or not ?

No, this does not seem reasonable to me at all. I have an MBA M2 with about the same age as yours; under a higher load the indicated battery life is twice as much.

Some plugins indeed take a lot of resource. I recently tried to set up a small cloud drive (in addition to iCloud) and stopped it after finding out that the process running it was reducing battery life by 40 % or so.

 

[!!!]

Perhaps Youtube changed policy again? Tried a few 1080p and 4K videos in both Safari and Chrome on my MBP 14 with M4 max, the codec was VP9. Here is one example.

I'm not really sure what you mean by youtube changing policy.

YouTube's "policy" (if you want to call it that) is that 1440p and higher videos won't be in H.264, so VP9 or AV1. I don't know why YouTube chooses one over the other, the only thing I can kind of see is that more popular videos are more likely to get encoded into AV1. When choosing what codec to playback it seems like it will choose AV1/VP9 over H.264, as long as your browser supports it.

 

[vanc]

I'm not really sure what you mean by youtube changing policy.

YouTube's "policy" (if you want to call it that) is that 1440p and higher videos won't be in H.264, so VP9 or AV1. I don't know why YouTube chooses one over the other, the only thing I can kind of see is that more popular videos are more likely to get encoded into AV1. When choosing what codec to playback it seems like it will choose AV1/VP9 over H.264, as long as your browser supports it.

Ok. The tests I did was with my MBP 14 with M4 max with macOS 15.7. Both Chrome and Safari prefer VP9.

When I tried on a MBA 15 with M2 with the latest macOS 26.0.1, Chrome/Safari both chose AV1 for the same videos, not only these 8K ones I tried before.

It looks like the OS upgrade caused the behavior difference. I don't really like it either. It means more power usage on M2 without the hardware AV1 decoder.