If an alkaline battery meets a conducive object while traveling, an electric current could be created and cause hazardous heat or sparks. To prevent this, the U.S. DOT requests that batteries be packed separately in nonconductive material, and that the batteries be properly insulated by taping both terminals of each battery or packing each battery in a separate plastic bag.
If it's practicable, the U.S. DOT suggests that all battery-powered devices you travel with be packed in separate inner packaging, or packaging within a suitcase or bag. Again, the material of the inner packaging must be nonconductive.
There is no limit to the number of batteries you can carry. But if your batteries are leaky, they may be transported as hazardous waste. No matter how many batteries you pack, always take them as carry-on. Flight attendants can monitor a hazardous situation, whereas a battery packed improperly would go unnoticed in the hold of a plane.
Do not mix alkaline batteries with another type of battery, such as lithium ion, lithium metal or acidic.
