Ever get frustrated trying to figure out exactly when your battery is going to hit 100% so you can take it off the charger? Well, Google's right there with you, apparently, because in the Android "L" release preview, your phone or tablet will now tell you how long it will take to fully charge.

It appears in both the battery menu of the settings and the lockscreen. You'll also find an estimated time until your battery hits 0% in the battery menu, though you accuracy may vary +/-allthehours, we've found. Hopefully there's some kind of learning algorithm in place here so that eventually the estimate will be useful for more than just posts on blogs about new features in Android. We can dream, right?

You'll also find the new battery saver mode in the settings area, and it's not much different from what you see HTC putting out these days (though not its extreme power saving mode, that's more intense), with Google estimating it'll give you an additional 90 minutes of use time on your phone when enabled.