Washington (DC) - Gadget lovers will have one more thing to worry about because the Transportation Department has issued new rules that greatly restrict lithium-ion batteries on airplanes. Effective January 1st, travelers will be limited to two spare lithium-ion batteries in their carry-on baggage. Furthermore, spare batteries in checked baggage must have their terminals covered with either tape or placed inside of the original packaging or a plastic bag.

According to a bulletin issued by the DOT, most gadgets like cameras, cell phones and laptops will still be allowed in both carry-on and checked luggage. However, the same bulletin states, "the rule limits individuals to bringing only two extended-life spare rechargeable lithium batteries, such as laptop and professional audio/video/camera equipment lithium batteries in carry-on baggage." Batteries installed inside of devices will still be allowed in both checked and carry-on luggage.

The Transportation Department says the new rules will prevent accidental fires in both the cargo hold and passenger compartments. Fires in the cargo hold will generally spread unnoticed until the automatic fire suppression systems do their work. The passenger compartment is less of a concern because any fire that starts can easily be detected by crew and passengers.

You can read the DOT bulletin here. The Transportation Security Administration has also issued their own guidelines here.

So in summary,

• Batteries inside of devices are OK in both checked and carry-on baggage
• Carry-on baggage - Limited to two spare batteries
• Check baggage - Unlimited number of spare batteries, BUT the batteries must be in their original packaging, in a plastic bag or have its terminals covered in tape.