Chromebooks offer a much longer battery life than the average Windows machine, but there’s still room for improvement. The upcoming Chrome OS 105 update introduces new browser optimizations will the intent of saving extra battery life.
Most browsers put inactive tabs to “sleep,” which is a cute way of saying that they disable or throttle tabs you aren’t actively using. This reduces the CPU load of inactive tabs, frees up some RAM, and preserves battery life.
Note that the “quick intensive throttling” flag is only available in Chrome OS 105 Dev. It will take a few months for Chrome OS 105 to exit the Developer channel and reach regular users.
Source: About Chromebooks