A Smartphone that Lasts a Week Between Charges? Sorry, No Time Soon

Rafe Needleman
·Editorial Director, Yahoo Tech
Updated
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(Thinkstock)

In the last fifteen years, we’ve seen mobile devices get smaller, faster, stronger, and just overall better. Except for one thing: their batteries. The energy density of batteries has only about doubled in the last 15 years, according to Microsoft Senior Researcher Ranveer Chandra, who spoke this week at the MIT Technology Review Digital Summit in San Francisco.

Chandra is trying to build a seven-day smartphone, a device that has seven times the unplugged longevity compared with most smartphones today. So what’s the secret to making a device last seven times longer than any smartphone today? 

There isn’t one. Sorry.

But there is hope. As Chandra says, a concerted, multifaceted approach to device energy-use can improve longevity a little bit at a time.

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One of Ranveer Chandra’s slides from the MIT Technology Review conference. 

For its part, Chandra says, Microsoft is making more data available to developers, to let them know where their apps are using more energy than necessary. That’s the first step.

He wants to make even more useful data available. For example, he wants apps to have data not just about how much energy the app is using, but also about how much energy the device is using overall. Because, he says, when a mobile device battery is supplying more power, it is also wasting more power. “Drawing six times the current reduces battery life by fifteen times,” he says. So he wants apps to be workload-aware. 

Read more: The Best New iOS 8 Features that Apple Didn’t Tell You About (including better battery monitoring)

Chandra also wants devices to be able to offload power-hungry processes to “PCs around you” or to the cloud. If, that is, the power use of transmitting and receiving the data would be less than it would be to do the processing on the device itself.

Finally, Chandra is pushing for devices to get multiple batteries that are managed (probably) by the system, to level out the high-current needs between batteries. This could extend a device’s overall battery life 15 to 20%, he believes. 

Unfortunately, there’s no new battery technology or chemistry coming to our devices soon; any potential battery breakthrough is years from release, Chandra said. 

So while Chandra, and the rest of us, are struggling with short battery lives on our devices, what can we do right now? Chandra has these common-sense tips:

* Turn down your device’s brightness. The display is one of the biggest energy drains. 

* Use WiFi whenever possible. LTE is much harder on batteries.

* Turn off GPS in apps when you don’t need it. 

And don’t expect to be able to stop worrying about your battery life soon.

More battery-saving tips:
* 12 Desperate Battery-Saving Measures for Your iPhone
* 4 Ways to Take Better Care of Your Laptop’s Batteries