Passengers are generally allowed one carry-on bag and one personal item. A laptop may be placed either in the carry-on bag or in a separate bag, which will serve as the passenger's personal item. The size and weight of the carry-on bag and personal item must comply with the limits implemented by the airline and the passenger's booking class. In general, a carry-on bag or personal item can have a maximum size of up to 14 inches by 9 inches by 22 inches and a maximum weight of up to 15 pounds. Some airlines require personal items to be smaller than the allotted carry-on size.
Although passengers can bring spare batteries for their laptops and other gadgets like mobile phones and portable media players, no spare batteries are allowed to be stored in checked baggage. A spare battery is defined as a battery not physically installed in a device. This means that a device with the battery attached to it can be placed in checked baggage, provided the battery contains less 25 total grams of lithium.
Although the possibility is generally low, laptop and other battery-powered electronic devices may pose a fire hazard. Lithium ion batteries may malfunction or overheat, and in rare cases they can catch fire. Most laptop batteries contain up to nine lithium ion cells that can become a fire risk when their internal temperature reaches 350 degrees. Passengers are advised to look for the mark of an independent testing or standards organization like the Underwriters Laboratories (UL) or the International Electrotechnical Commission (IEC) to make sure that a laptop battery complies with international safety standards. Check battery recall information at the Consumer Product Safety Commission or the manufacturer's website, as well.
