With Verizon’s 4G network covering a good chunk of the country and AT&T gaining ground, more smartphone users have access to the fastest wireless service available. But because 4G coverage isn’t truly continuous in many locations, users’ batteries are taking a big hit.

“I love everything about the phone, but with 4G on, it just sucks down the battery,” one Verizon Wireless customer explains to the Wall Street Journal. “It’s very frustrating. Why can’t I get a phone to last a whole day?”

The problem, reports the Journal, is that 4G phones in areas with spotty 4G service spend an awful lot of battery power trying to hunt down a signal.

“So you’ve got a situation where the phones are sending out their signals searching and searching for a 4G tower, and that eats up your battery,” says Carl Howe, a vice president for research firm Yankee Group.

Improved networks will help curb this issue. But as 4G becomes more readily available, you can expect people to use their phones for more battery-draining purposes like streaming video or browsing more web pages than they would on a slower network. Many of the latest phones have batteries that are not capable of handling such a workload for any extended period of time.

The one phone that is getting the most attention with regards to battery life is the new Droid Razr Maxx, which promises upward of 21.5 hours of continuous talk time. I got my hands on the device back in January, but wasn’t able to give the battery any more than a cursory test.

However, my cohorts at Consumer Reports are now putting the Razr Maxx through the gauntlet — and with decent results.

“My informal tests suggest the Razr Maxx’s battery life is simply astounding,” writes CR’s Mike Gikas, “and the best I’ve ever seen on a smart phone.”

After a full day of moderate-to-heavy use on Verizon Wireless’ 4G LTE network, he found that the phone retained around 75% of its battery power.

And on the streaming video front, he was able to stream “Iron Man 2” from the HD Netflix app for almost three entire viewings before the battery died. The non-Maxx version of the Droid Razr conks out 30 minutes into the second go-through of the movie.

Fast Phones, Dead Batteries [WSJ.com]

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