Google Chrome is both the most popular and most reviled browser in the world, mostly because it will kill any laptop battery more thoroughly and mercilessly than Jack The Ripper (if you have multiple tabs open) (and you do). So Google is fixing Chrome to stop sucking your battery dry, mostly by keeping webpages from cranking.
The problem with tabs is that individual webpages are enormously complex things, some of them basically the equivalent of desktop apps in of themselves. That means even when you’re not on the page, they’re still running and thus need CPU cycles, slurping up battery that much faster. So Chrome has a new policy that limits how much CPU can be used by most webpages. Unless they’re playing music, or running WebSockets or WebRTC (the software behind persistent chat apps like Slack), they’re cut off at the bar.
This won’t solve all of Chrome’s battery issues, and the team is working on a way to suspend pages that aren’t currently being viewed completely. That, of course, probably won’t happen for a while, since there are pages you want going in the background. But, for now at least, Chrome will be slightly better. To upgrade, just go to Settings under the menu up on the right-hand side, click “About,” and it should update automatically.