Mobile battery life improves, but not how you’d think

Battery life: It’s the bane of a mobile device, second only to spotty mobile broadband coverage in terms of annoyances. Although some promising battery technology developments have appeared in the past decade — here’s 25 of them — by and large, we’re generally using the same battery tech as we did before the smartphone market exploded. Is the situation really that bad? Perhaps not.
I realized this after a training run on the roads yesterday. I ran a 7.25 miles in leisurely 61 minutes with my smartphone. When I left the house, I had a fully charged battery. At the completion of my run, the battery was down to 90 percent, so I used one-tenth of the battery in that hour. But with all of the sensors and functions going, I think the handset ran harder than I did.
During the run, I used a mobile application to monitor my pace, distance and location; the app was constantly updated by the phone’s sensors. Which ones? The GPS and Bluetooth radios were constantly feeding the app with key data. That includes my heart rate, which was tracked by low-power Bluetooth 4.0 chest strap. I also listened to music the entire time, with the volume level around 60 percent. Oh, and of course the cellular radio was active for voice and data, although I did turn off the Wi-Fi radio.
Think about that for a second. Between mobile apps, radios, sensors and even occasional screen wakes to see my progress, my phone was able to do a fair number of functions for the entire hour, using one-tenth of the battery capacity.
When I think back to the pre-smartphone days, I remember my PDA devices quickly drained the battery. Some of these had large screens — I bought one of the first color Pocket PCs a dozen years ago — perhaps a Wi-Fi radio and few other sensors or radios. And yet, I might have gotten two full days of battery life at that time, but generally had to charge my devices each night. That’s essentially no different that today.
But what is different is the number of sensors, features and functions found in the devices of today. We can do so much more on a single charge.
Instead of major battery advances, hardware makers have implemented highly integrated chips, such as silicon with 3G, 4G, Bluetooth, Wi-Fi and even FM radio support on a single chip, for example. Plus that Wi-Fi radio pulls double-duty: It’s now a gateway to share a mobile broadband connection with your other devices.
Display technology has improved too, using less power to backlight the screen even as we move to high-definition resolution. And software is far more optimized to work with the chips that power our phones and tablets. The processors on our chips are also smarter, ramping up in power as needed, but slowing down or offloading instructions for smaller or less-intensive tasks, which saves on power.
Sure, I’m just like everyone else and want to see a device that lasts for days on a charge. But I’ll happily take a handset that adds more radios or sensors without a major battery hit too. If I can get more “bang per watt” out of my mobile gadgets, I’m happy.