Carry-On Or Checked Baggage?
The FAA has banned standalone or spare lithium-ion batteries in checked baggage. For instance, passengers aren't allowed to check an extra laptop battery or a smartphone "power bank" in their luggage. The FAA still allows those batteries in carry-on bags and hasn't put a limit on how many batteries you can bring. Electronic devices that contain lithium-ion batteries (such as laptops) are OK in checked baggage, too – as long as the batteries are 100whr or less. Larger battery sizes require airline approval. However, because there isn't a universal regulation in the U.S., the rules may differ by airline.