Common consumer electronics such as travel cameras, cell phones, and most laptop computers are still allowed in carry-on and checked luggage.  However, the rule limits individuals to bringing only two extended-life spare rechargeable lithium batteries, such as laptop and professional audio/video/camera equipment lithium batteries in carry-on baggage.

“Doing something as simple as keeping a spare battery in its original retail packaging or a plastic zip-lock bag will prevent unintentional short-circuiting and fires,” said Krista Edwards, deputy administrator of the US Department of Transportation’s Pipeline and Hazardous Materials Safety Administration. 

Lithium batteries are considered hazardous materials because they can overheat and ignite in certain conditions.  Safety testing conducted by the Federal Aviation Administration (FAA) found that current aircraft cargo fire suppression systems would not be capable of suppressing a fire if a shipment of non-rechargeable lithium batteries were ignited in flight.