To save power, we must first understand what’s using that power. To that end, Battery Historian was developed. It’s a new tool in Android L that lets you “visualize power events over time” to help you understand how apps are using your battery. As developers come to a better understanding of how their apps use power, they can utilize a new job scheduler API to help that app know when tasks and other jobs should run. Various tasks may be scheduled for when your phone or tablet is idle, or when it’s connected to a charger, thereby saving battery power by shifting the load to times when it will have less impact on your charge.
Based on that explanation I didn’t expect to see any remarkable results from the battery on my well-used Nexus 5 running the Developer Preview of Android L. I was pleasantly surprised — and stymied at the same time.
Whenever we run a device through a Review Rebuttal or an After the Buzz process, we usually spend the first day getting it all set up. We install apps, input credentials, and basically configure it just like our previous device. What good is a test if we don’t have a stable baseline, right?
Once we’ve got everything set up, we charge that puppy as much as we can, then put it use it for a few days. Once we’ve got some miles behind us, we can report on how that particular device compares to the one that we’ve chosen to be our personal daily driver.
That’s what I did when I installed the Developer Preview of Android L on my Nexus 5. The initial setup required a factory wipe (as expected). From there I started the long process of getting all my apps installed, built-in apps updated, credentials input, and everything set up exactly as a I like it. Then I noticed something unusual: my battery was at 59%.
This was curious considering that typically, running through the same process on my Nexus 5 will throw a low-battery alert at 15% (or thereabouts), forcing me to finish the process while tethered to external power. This time, however, I got through the whole thing with less than half my battery having been consumed. Wow!
My typically daily routine has me checking my phone before heading off to my day job, charging while in the car, then keeping my phone on my Qi charger at work. With Android L, I kept my phone in my pocket rather than on the charger. At the end of the day I still had plenty of juice to spare. On a typical day I’d get that dreaded low-battery alert right before turning in for the night.
A Little Stymied
For approximately two weeks I ran Android L as my daily driver. It wasn’t all rainbows and unicorns. I had my fair share of hiccups and problems, which ultimately led me to conclude that you probably don’t want to run Android L as your daily driver — not yet anyway.
During that time, battery life wasn’t consistent. Some days I’d get through an entire day without touching the charger. Other days I’d barely make it to lunch before I was in the red. The new tools, which I’d expected would help me track down power hogs, listed new and cryptic processes that were chewing away at my battery, offering me no help finding the culprit.
It’s worth mentioning that the only apps that are currently optimized for Project Volta are those that come prepackaged with the Android L Developer Preview. Third-party apps will take time before code is written to make them play nice with the new features.
In the meantime, Android L is still a preview, and Project Volta certainly shows promise. I just hope the kinks are worked out before it starts rolling out to devices later this Fall.