What are the rules?
Samsung Galaxy Note 7 smartphones has now been banned onboard airlines worldwide, following a series of widely publicised incidents where the phone's batteries combusted causing fires.
Could this possibly happen with camera batteries too?
Cell phone manunfacturers compete to make their phones last longer on a charge while weighing less and thus pack a lot of charge in a very tight space. If a shortcut arises for any reason, the build-up of heat can lead to a fire. Camera batteries tend not to pose such a high risk as they do not contain as much energy as phone batteries do, but they can still be the cause of a fire if they are not treated correctly. Airlines allow lithium-ion batteries to be carried in carry-on luggage as a fire can be dealt with more easily in the cabin than in the hold.
There are, however, restrictions to observe. The US Federal Aviation Authority (FAA) stipulates that:
Spare (uninstalled) lithium ion and lithium metal batteries must be carried in carry-on baggage only. When a carry-on bag is checked at the gate or at planeside, all spare lithium batteries must be removed from the bag and kept with the passenger in the aircraft cabin. The battery terminals must be protected from short circuit.
Some airlines recommend that the contacts are covered with tape. Better still is to place each battery in its own protective case, plastic bag or package, such as the original retail packaging. Other methods include using a battery case, using a battery sleeve in a camera bag, or putting them snugly in a plastic bag or protective pouch.
Take steps to prevent crushing, puncturing or putting a high degree of pressure on the battery, as this can cause an internal short circuit, resulting in overheating. Lithium ion (rechargeable) batteries are limited to a rating of 100 watt hours (Wh) per battery.