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.
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.
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.