Yes, you can bring AA batteries on a plane. According to TSA regulations, dry batteries such as C, D, AAA, and AA are allowed to be packed in both carry-on and checked luggage.
Checked Bags: NoSpare (uninstalled) lithium ion and lithium metal batteries, including power banks and cell phone battery charging cases, must be carried in carry-on baggage only.
lithium metal and lithium ion/polymer batteries are prohibited in checked baggage—this includes external battery packs. Electronic cigarettes and vaporizers are also prohibited in checked baggage. “Checked baggage” includes bags checked at the gate or planeside.
Devices containing lithium metal or lithium ion batteries should be carried in carry-on baggage. Most other consumer electronic devices containing batteries are allowed in carry-on and checked baggage.
Is toothpaste considered a liquid by the TSA? Yes, toothpaste must adhere to the 3-1-1 rule for liquids and gels. Toothpaste can be brought through TSA security in your carry-on as long as it is 3.4 ounces (100 milliliters) or less and placed in a 1-quart bag.
A flashlight that is less than 7 inches in length and is not classified as a tactical weapon can be brought on a plane through carry-on. You can bring any flashlight through checked luggage but you must carry lithium batteries with you in your carry-on bag.
Safety Razors: Because the razor blades are so easy to remove, safety razors are not permitted in your carry-on luggage with the blade. They're fine to pack in your carry-on without the blade. The blades must be stored in your checked luggage. The same applies for straight razors.
A: The bags are scanned for security, not specifically for lithium batteries. If you leave a lithium battery in your bag it will travel with you. It is safer for the battery to be in the cabin so that if a thermal runaway occurs the cabin crew can deal with it.