There are a lot of new features in Android M, the latest version of Google's operating system, announced earlier this month at its developer conference. But perhaps none will affect most people's day-to-day smartphone usage than Google's promise that Android M will improve battery life.

The early tests are in, and Android M appears to be a big improvement in energy usage. Several enthusiasts and outlets have installed Google's beta version of Android M on their smartphones and are reporting back that they're seeing significant gains in standby battery life. 

"After 48 hours, the Nexus 5 with Android 5.1.1 inside had devoured 24 percent of its battery power compared to the 9 percent used on the Android M powered version of the phone," Alan F. writes for Phone Arena. He also notes that his phone's standby estimate shot up from 200 hours to 533 hours after installing the update. 

There is one main program that will help your beleaguered battery in Android M. It's called Doze, and it puts apps into "deep sleep" when you're not using your smartphone, which ends up saving a lot of power. It's part of a toolkit called App Standby, which restricts when apps can sync data and execute tasks. For instance, if you're not using an app currently, App Standby will make sure it's not running in the background, using up your battery. 

Unfortunately, these tweaks won't significantly improve battery life when you're actively using your phone -- like playing games or making calls. 

Now comes the hardest part: the waiting game for Android M. If you've got a Nexus device, you can install one of Google's developer previews now. If you've got a Samsung Galaxy or other mainstream Android smartphone, first you'll need to wait for Google to officially launch Android M to consumers, which should happen sometime this fall. Then, you'll need your carrier or hardware maker to adapt the operating system for your specific phone. If all goes well, there's a chance you'll have this new power-saving feature on your phone by the holiday season.