The U.S. Transportation Department has barred travelers from packing loose lithium batteries in their checked bags on all flights. The Pipeline and Hazardous Materials Safety Administration said the move is designed to help minimize the risk that such batteries could overheat and catch fire on board.

These rules beginning January 1 say travelers can bring a laptop, cellphone, digital camera, and other equipment on board their flight as long as the batteries are installed in these items. Fliers can also bring spare batteries in carry-on luggage if they’re in the original retail packaging. There is a limit of two spare batteries per traveler.