Smartphones, tablets and laptops have expanded Americans' capacity to communicate in a crisis, experts say - if they're charged and ready to go.

This weekend, with massive Hurricane Irene threatening to disrupt power supplies all along the East Coast, the most reliable one-way transmitter of information may well be the battery-powered transistor or hand-cranked radio.

However, with a little planning, ways to power up newfangled two-way devices and ensure their operability for voice, text, email and online access to information are also available, educators and consumer electronics experts say.

"The devices without a network or power are just bricks in our pockets," advises Paul Eng, web senior editor and blogger for Consumer Reports. "Some of the charging options will help them from becoming a brick. But there's no guarantee."

More than 300 million cell phones are in use in the United States, and tens of millions of those are smartphones, said Jason Oxman, a senior vice president of industry affairs at the Consumer Electronics Association in Arlington, Va.

"Radio and television is a great way for dissemination of a single message to everyone for an entire viewing area, but the problem with radio and TV is, they're not two way and can't be tailored in any way to the needs of an individual user," Oxman said. "The television's not going to tell me if my family's OK. For the nearest Red Cross shelter, I can find that out with my smartphone app."

The first step is to make sure devices are powered up in advance, said Alex Halavais, Interactive Communications professor at Quinnipiac University. If the power goes out, the home router doesn't work for laptops or tablets, and phones cannot be recharged as easily.

"It turns out that cell phones are one of our best lifelines, at least recently," Halavais said. "We saw that in the Japan quake. Those networks are fairly resilient."

Eng and Oxman say wireless networks are more robust than consumers might think. If the power goes out, a cell phone will work if it's charged, or can be powered up with a car charger, more and more of which use universal mini or micro USB ports and can charge up laptops and tablets, too.

Consumers can also buy extra batteries or portable chargers for a smartphone, they said.

"If you're outside, the cellular data network that the smartphone uses runs on the same infrastructure as the cellular voice network - the same towers, the same signals," said Oxman. "So if power goes out and WiFi is down in your house, you will still be able to use your smartphone, whether it's AT&T, Verizon, Sprint or T-Mobile."

Texting uses less bandwidth than calling and voice messaging, so it's a great way to make sure your message gets through, Oxman said.

In emergencies, phone messages may be swamped through the switchboard or network, but the lower bandwidth for texting gives the ability to "be short and sweet and get your message across," said Bruce White, professor of computer information systems at Quinnipiac.

Wireless network providers do "a great job" maintaining backup systems for wireless networks the same way they do for the wire lines, because they have so many customers, said Oxman. AT&T said this week it has added capacity to its wireless network to accommodate increased call volume and tested high-capacity backup batteries located at every cell site.

Phil Simon, Quinnipiac's director of its Master of Science Interactive Communications program, noted that cell and smartphone calls may not get as jammed up in a hurricane and its aftermath, which can last hours, days and weeks, the way they did during the earthquake that hit the Northeast on Tuesday afternoon.

"With a hurricane, it's going to be a rolling wave of use," he said.

If consumers don't have easy access to charging devices, or the power goes out, Simon suggested having a family communications plan in place and minimizing the number of calls.

"If you don't have power and can't recharge your cell phone, turn it off between calls," he said. "And tell your family, 'If it doesn't connect, that means my phone is off.' If you only use your cell phone at certain times during the day, it can remain powered for weeks. Or set a designated time to receive a call, because you want to save it for an emergency."

In his blog, "Hurricane survival tips for your electronics," Eng advises putting together a "go-bag" of essential electronics equipment and protective plastic sandwich bags to protect them from the water.

"We've become so accustomed to using our devices in all kinds of situations, but in a hurricane, you can drop your phone, it can get wet and lose its charge," he said.

In that go-bag, also put spare batteries, rechargeable batteries for your phone, batteries for your laptop and tablet, a car charger and removable external hard drives with backup data in case your PC or laptop is destroyed in the hurricane. Low-tech items like radios, a whistle and paper maps can be indispensable, too, he said.

The most reliable device, Halavais conceded, "will still absolutely be the radio."

p.daddona@theday.com