> arious System76 laptops, Thinkpads (among many other laptops recommended by Linux users) give you battery life comparable to macOS on the M1.

that is a lie. system76 and thinkpads are nowhere close to giving you a full day of battery life on Linux.

I keep hearing about battery life being just as almost just as good or better on linux (and on Windows too, though that's a more realistic claim). Yet even the latest gens thinkpads are pretty awful w.r.t battery. My friend bought an i5 12xxx Thinkpad X1 and can barely do 5 or 6 hours of screen on time, when the stated capacity is 16h. Lenovo denied a refund, because it's working as intended according to them (and my colleagues with s76 laptops don't even really expect more than 3-ish hours of battery at best). My work provided t14 gen 3, that I like, can't even keep it's charge when unplugged and in my bag for long enough.

And I'm no Apple fanboy, the only Apple device I've ever used has been an ipad 5 years ago and my M1 macbook.

Lenovo’s battery life numbers are consistent generation to generation, but wildly unrealistic. My 2015 thinkpad (since replaced by m1 air) was rated as 12 hours but could do at most half in practice doing very light tasks and typically ran about 4 hours. So when you buy a thinkpad you should assume actual battery life is a third to half of the rated life.

Apple’s numbers are equally unrealistic. They rate my m1 air for 15 hours, but in practice it gets to around 8 hours.

My macbook pro was rated for 18 hours and I find it very easily meets or exceeds that number if I'm working on general tasks.

Of course if its a day where I'm compiling often and have several tasks running its going to be lower, but thats not the usecase they advertise

Eh... I have a T480. It's advertised at "17+" hours. With the 72Wh extended battery fitted, it has a total of 96Wh energy storage. With some small effort tuning (making sure the nvidia GPU is properly powered down etc) I can easily get its consumption down to about 5W - less, with lowered screen brightness and wifi off. 96Wh / 5W = 19h 12 min. Seems legit.

Just a sample size of 1, but my HP ProBook 430 G3 (6th gen i5) could comfortably hit 8 hours of battery life, or beyond 10 on light tasks - before the battery went kaput unfortunately. However it was the “large battery” variant with I think a 40 or 50ish Wh capacity on a 13” screen.

System76 systems absolutely do not have good battery life. The systems the make tailored only to battery life try to be comparable in battery (~14h system76 to ~25h on m2 pro) but obviously x86 vs arm makes this attempt exceedingly difficult. You're going to remove a massive amount of computational power from an x86 system to improve it's battery life like that. However, of course if you're interested in increasing a laptop battery life, it helps to have control over the system if you have the time to put forth on optimizing it. I would imagine an asahi linux (archlinuxARM) system could be made to last much longer than macOS. However, this would require 1) not running any wm, or perhaps a simple one like awesomewm, 2)drastically reducing screen brightness, 3) removing any processes that run in the background continually (you could take this rabbit hole far - perhaps even to NTP requests and such), etc. MacOS doesn't have as much configurability like this, so it's variance in battery life is much less - probably a range of 10h-37h if you really push it. Linux could probably take that to 20min-8days if you tried.

I had a ThinkPad T14 AMD and the battery life on Linux was very mediocre, even after tuning with powertop. It was usually 2-4 hours, on Windows more like 8-9 hours.

Conversely, I'm on a Gen 8 X1, and on Silverblue with tlp replacing power-profiles-daemon, I routinely get 8-9 hours. Anecdata and whatnot, but I'm pretty happy with modern linux + modern hardware. That's not to say I wouldn't love to get my hands on an M1 macbook to see the difference though...

It's almost as if "Linux" said very little about what software people are running, in what configuration.

Right, and that is the issue. If I buy a Mac and run MacOS I can be sure that I get long battery life. If I get a PC laptop and run Linux, it's a random crapshoot if the random combination of hardware, kernel version, etc. (I also used Silverblue and Fedora) of whether you get a good battery life.

Maybe Asahi Linux will improve things, since they only target a very small number of hardware configurations.

That hasn't been my experience... If anything System76 are much much worse, and Thinkpads mediocre in that aspect