Smart phone processors and download speeds are many times faster than just a few years ago. So why hasn't battery life made similar leaps?
When the first smart phones came out, no one looked forward to a future in which we constantly had to duck into coffee shops to charge our phones. Yet, here we are.
In the five years since the introduction of the original iPhone, mobile devices have sported bigger and brighter screen, faster processors, and swift 3G and 4G data connections. But battery life is about the same as it's always been – barely adequate for a full day's work.
Why does it seem that, in spite of all these other advances, our phones' battery life never gets any better?
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While you may not know it, lithium-ion batteries – the kind that power everything from smart phones to laptops – have actually gotten about three times more efficient since the mid-1990s. But in the same time, the electronics they power have improved more than a thousand-fold. Your new phone's big, bright display draws way more power than the smaller, dimmer one on your old phone, putting more stress on the battery and forcing you to either use the screen sparingly or retreat to a wall outlet for a mid-afternoon charge.
There's also the "thin and light" aesthetic to consider. “You can have a battery that's the same size as before but lasts three days, or you can have a battery that lasts a day but is a third the size," says Steve Harris, who researches battery technology as a visiting scientist at the Lawrence Berkeley National Laboratory.
In other words, even as researchers are able to pack more energy into batteries, we don't see longer-lasting phones – we see phones that last about the same amount of time as before, but with a thinner profile.