Motorola CEO Dennis Woodside spoke yesterday at the D11 conference about an upcoming smartphone called the Moto X that constantly uses its onboard sensors to figure out where it is and what its owner is doing. He didn’t fully explain how Motorola can do that without reducing the device’s battery life to less than that of smartphones that don’t try to follow their owner’s context, though.

Woodside said the phone, set to appear later this year, would keep its accelerometer, gyroscope, and other sensors on at all times:

“It knows that when I take it out of my pocket I might want to do something, I might want to take a picture so it’s gonna fire up the camera…Imagine when you’re in the car the device will know, whether it’s on or off, that it’s travelling at 60 miles per hour, so it’s gonna act differently. It’s contextually aware of what’s going on around it, it allows you to interact in very different ways than you can today with other devices.”

However, having a phone that keeps its sensors on at all times (and processing the data gleaned from them) requires using power, which is one reason few popular apps do that today. Woodside said that Motorola has expertise in low-power sensors, but they would have to be significantly more efficient than those currently in use to allow near-constant use without asking much more of the battery.

Assuming the Moto X is to offer comparable battery life to other phones, it likely needs more than just better sensors–perhaps a bigger or somehow improved battery technology. Something other than improved sensors will be even more crucial if what Larry Page said last month about upcoming Motorola devices offering better battery lives than existing phones (see “A Long Lasting Phone? Google’s Larry Page Says It’s Coming”) is to apply to the Moto X.