When apple redesigned the MacBook Pro in 2009, it used a new battery that gave it 40 percent longer battery life than the previous model. The laptop can last seven hours, enough to watch the movie "Lawrence of Arabia" twice. Apple marketing chief Phil Schiller called the battery "revolutionary," but is it?

The technological leaps that have taken place over the past 20 years are truly astonishing. Computers have shifted from utilitarian boxes to bright rectangles of metal and glass, small enough to fit in a pocket. Today's devices are much more powerful. A new smartwatch has more computing power than the Apollo spacecraft. Batteries, however, are another matter.

Even as makers of consumer electronics, from apple to samsung, invest millions of dollars in research to make their devices last longer, the technology itself will not change dramatically in the next few years. But that will not slow the rising number of gadgets that rely heavily on power batteries.

Why power battery technology has stalled has been a topic of debate among researchers, with many saying we have reached the limits of science. Whatever the real reason, consumers will need to make the most of battery-powered devices.