Don't forget that new rules regarding air travel with lithium batteries take effect on January 1. Spare lithium batteries -- meaning those not installed in the devices they are intended to support -- may not be packed in checked bags. Spare batteries in carry-on baggage must remain in the original packaging or be placed in plastic bags so that leads are not exposed.

Batteries, whether spare or installed, are also subject to quantity restrictions. Those with up to 8 [grams]-oz. of lithium, or about 100 watt-hours, are allowed. That includes cell phone lithium ion batteries, as well as most laptop batteries. You can also bring additional spare batteries with an aggregate of up to 25 [grams]-oz. of lithium, or 300 watt-hours. However, you may only bring up to 2 [grams]-oz. of lithium metal per battery. Most consumer lithium metal batteries are below that limit, but check with the manufacturer of your devices if you are unsure.

In a nutshell, traveling with most lithium batteries intended for consumer devices should be okay, but those for professional grade equipment may be confiscated.

The fear is that non-rechargeable lithium batteries may pose a fire hazard. The FAA has found that the fire-protection systems in the cargo holds of passenger planes cannot extinguish fires sparked by lithium batteries. And the NTSB has not ruled out that a fire in a cargo plane at Philadelphia International Airport last year was caused by lithium batteries.

[Updated units of measure.]