Gee, maybe it's because you have a million tabs open, and all of them are websites with shitty, wasteful javascript begging the CPU for useless operations to update every single tracking pixel and cookie, with up-to-the-minute anaylitics, attached to sessions that are years old, on how your eyes move over their ad banners, so that a genetic machine learning algorithm can determine which ads are most likely to convert to clicks and then sales.

Hint: It's the ad for the top 7 ways you didn't know you could get bunions, and there's a 50% chance it will convince you to buy new shoes.

You are being downvoted, I assume for your "over the top" tone, but your overall message is very good. User behavior is the largest determinant of battery life.

I run Firefox with NoScript, and my battery usage is always very very good. An additional benefit is that I see few ads, since they invariably rely on third-party javascript.

89% charged, 4h calculated time http://replycam.com/i/batterylifetime_1BE12F3F.png (but in reality, it will be shorter)

yeah, chrome is in there.

but switch to safari? my thoughts a) i'm a developer, i rather like new APIs, latest HTML 5 features b) my whole company infrastructure relies on google services (and they work best in chrome, no surprise there) c) my old macbook air (2013, maverick, killed one month ago by my son with self made kombucha) had about 7h battery-life

I'm not arguing you should switch to Safari (which I like) or arguing feature merits (I don't care much myself). But if you have a Mac you have Safari, so it's an easy test to run. And you will be AMAZED at the difference in battery life. It's pathetic.

Agreed. I stopped using Chrome at home. It was weird moving to Safari but I get much longer battery life now.

To be fair that's not super useful information - I've never not seen Safari there when it's being used. Definitely agree that Chrome is way worse in practice though.

I'm not saying Safari is 'free', I'm saying that Chrome's battery use is very disproportionately high.

Chrome also turns on the discrete GPU for seemingly no reason.

Matters for machines that have them (like mine) but even in integrated only machines it makes a huge dent in battery life.