Due to a few recent fires among commercial airplanes, the US government is considering new restrictions on how passengers carry lithium batteries used to power laptop computers and cell phones onboard.The Department of Transportation is expected to propose further restrictions later this year after restricting bars of bulk shipments of some lithium batteries on passenger planes. The government is not planning to ban batteries from carry-on luggage, however, new rules may prohibit them from checked bags.According to Bob Richard, deputy chief of the DOT's Pipeline and Hazardous Material Safety Administration, "We recognize that the American public wants to be able to carry their batteries and electronic equipment aboard aircraft, but we have to weigh the safety issues.....Any fire aboard an aircraft is unacceptable."

Fire safety officials, airline pilots and consumer groups are pushing for new rules on the batteries. At least nine fires involving lithium batteries have happened on airplanes or cargo destined for planes since 2005. None caused serious injuries. Lithium batteries are mostly used and there are 2 types: lithium metal (single-use) and lithium-ion (rechargeable). Lithium batteries store more energy than traditional batteries. When that energy discharges suddenly during a short circuit, it generates intense heat. A short circuit can occur when metal touches both terminals on a battery or when internal seals fail. Most lithium battery manufacturers install safeguards against short circuits and overheating. However, some low-cost or counterfeit batteries lack such protections, and manufacturing defects have rendered the safeguards useless in others. In the past year, more than 4 million lithium batteries have been recalled for such problems, including 100,000 last week.