Most mobile devices use lithium batteries because they are powerful. However, they can be dangerous, which is why the United States and many other countries have aviation regulations concerning them. Here are three things you need to keep in mind when flying with your mobile device.
No matter whether you are traveling for business or pleasure, you will probably take at least one mobile device with you. Most modern portable electronic devices use lithium batteries — either lithium-ion or lithium-metal — because they are more powerful than their dry-cell counterparts (e.g., alkaline and nickel-cadmium batteries). However, lithium batteries are also more dangerous. Besides being very flammable, they can generate a significant amount of heat and even self-ignite under certain conditions.
Due to the dangers, many countries have aviation regulations concerning lithium batteries. For example, in the United States, the Federal Aviation Administration (FAA) has several regulations governing what airplane passengers can and cannot do when flying with lithium-battery powered devices and uninstalled (aka spare) lithium batteries. Here are three things you need to keep in mind when you are getting ready for your flight:
The FAA does not allow uninstalled lithium batteries or portable battery chargers that contain lithium batteries in checked baggage. That’s because FAA researchers found that lithium batteries can self-ignite under specific conditions, such as when they are heated to extreme temperatures, short-circuited, or physically damaged. In addition, certain external conditions and internal malfunctions can cause lithium batteries to overheat through a process called thermal runaway — the temperature and pressure inside the batteries’ cells increase faster than the heat can be dissipated. Batteries in thermal runaway can reach temperatures above 1,100 degrees Fahrenheit, which is hot enough to ignite paper and cardboard.
You are allowed to keep spare lithium batteries and portable battery chargers in carry-ons, as the environmental conditions in the passenger cabin are much more palatable for them. You just need to protect the battery terminals from short circuiting, which can be done by simply covering them with tape or putting the battery in a protective pouch. Even if a battery were to experience thermal runaway due to an internal malfunction, the problem would likely be noticed and dealt with much quicker in the passenger cabin than the cargo hold.
Before you pack your spare batteries, though, you need to be familiar with a few requirements. A lithium-metal battery cannot have more than 2 grams of lithium in it, and a lithium-ion battery cannot exceed a rating of 100 watt-hours. These limits shouldn’t pose a problem for the average passenger, according to the FAA. If you happen to have a larger lithium-ion battery (e.g., a spare extended-life battery for your laptop), you can ask the airline for permission to bring it onboard. With airline approval, passengers can carry up to two larger (101-160 watt-hours) spare lithium-ion batteries. Other than that quantity limitation, there are no other restrictions on the number of lithium batteries you can put in your carry-on, provided they are for personal use.
The FAA prefers that you store your lithium-battery powered devices in a carry-on. However, if that is impractical, you can put them in checked baggage.
If you are going to store a lithium-battery powered device in checked baggage, it is important to take a few safeguards. You need to turn off the device, but before doing so, you should disable any features that could turn it back on, such as an alarm clock. In addition, you need to pack your device so that it is protected from accidental activation and physical damage. For example, if an unprotected device is placed next to a hardcover book in a suitcase, rough baggage handling or turbulence could cause the book to shift and inadvertently turn on the device.
Physically damaged lithium batteries can cause fires and other serious problems. Thus, it isn’t surprising that you are not allowed to take damaged batteries on flights, no matter whether they are spares or inside devices.
You are also not allowed to take defective lithium batteries and lithium-battery powered devices with battery safety issues on flights for the same reason. The FAA uses the US Consumer Product Safety Commission’s Recall List to determine what defective items to ban. For example, the FAA has banned certain Apple MacBook Pro laptops and HP ProBook notebooks based on this list. Apple and HP have recalled these devices because their batteries can overheat and cause a fire. If you have one of these devices, you are required to have the problem fixed per the manufacturer’s instructions before you fly with it.
While most people would agree that banning physically damaged lithium batteries is a good idea, there is no easy way to enforce the ban. Transportation Security Administration (TSA) agents might notice that a spare battery is damaged when checking carry-ons, but they do not check the batteries inside devices. A device owner might not even realize damage exists, as opening the device to check the battery might need to be done by the manufacturer or an authorized service provider.
Similarly, these is no easy way to enforce the ban on recalled lithium batteries and lithium-battery powered devices. The FAA admitted this in a Safety Alert for Operators (SAFO) report:
“It should be noted that is often difficult to distinguish products that are subject to a recall from those that are not. Many product recalls only affect certain batches of serial numbers of the same product model. Other recalled products carried by passengers or shipped as cargo may have already been repaired or had the defective lithium batteries replaced. Therefore, active screening methods at the point of acceptance or check-in may be difficult.”
So, if your lithium battery or lithium-battery powered device has been recalled and you haven’t had the problem fixed yet, you probably could get away with bringing it on your next flight. But given the seriousness of the potential risks, you probably wouldn’t want to anyway.