The Department of Transportation’s Pipeline and Hazardous Materials Safety Administration, or PHMSA (I like to say it “pa-hum-sah” just to be a jerk), dropped a bomb on us recently with a new set of regulations governing lithium-based batteries in public transportation (chiefly air travel, but presumably any transportation system under the DOT’s oversight).

Of concern are so-called primary lithium or lithium metal batteries as well as the somewhat more common lithium ion batteries so familiar to photographers. The regulations basically prohibit loose spare batteries in checked baggage and also place a number of other restrictions on the number and variety of batteries that can be kept in carry-on luggage.

I became concerned because I will be flying out to the California coast at the end of February to scout locations for future art photography workshops and making that voyage across the country is enough of a hassle without TSA inspectors throwing all of my batteries away.

Here I will make a valiant effort to summarize what has already been said by others and tell you why I think this “emergency” might be somewhat blown out of proportion. Continue after the jump!

The Facts

Before I get into the details of this new set of rules, you should probably know what the rules actually say. So, for your convenience, here is the actual DOT PHMSA press release in full:

Friday, December 28, 2007

Contact: Patricia Klinger or Joe Delcambre Tel.: (202) 366-4831

New US DOT Hazmat Safety Rule to Place Lithium Battery Limits in Carry-on Baggage on Passenger Aircraft Effective January 1, 2008

Passengers will no longer be able to pack loose lithium batteries in checked luggage beginning January 1, 2008 once new federal safety rules take effect. The new regulation, designed to reduce the risk of lithium battery fires, will continue to allow lithium batteries in checked baggage if they are installed in electronic devices, or in carry-on baggage if stored in plastic bags.

Common consumer electronics such as travel cameras, cell phones, and most laptop computers are still allowed in carry-on and checked luggage. However, the rule limits individuals to bringing only two extended-life spare rechargeable lithium batteries (see attached illustration), such as laptop and professional audio/video/camera equipment lithium batteries in carry-on baggage.

“Doing something as simple as keeping a spare battery in its original retail packaging or a plastic zip-lock bag will prevent unintentional short-circuiting and fires,” said Krista Edwards, Deputy Administrator of the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration.

Lithium batteries are considered hazardous materials because they can overheat and ignite in certain conditions. Safety testing conducted by the FAA found that current aircraft cargo fire suppression system would not be capable of suppressing a fire if a shipment of non-rechargeable lithium batteries were ignited in flight.

“This rule protects the passenger,” said Lynne Osmus, Federal Aviation Administration (FAA) assistant administrator for security and hazardous materials. “It’s one more step for safety. It’s the right thing to do and the right time to do it.”

In addition to the new rule, PHMSA is working with the FAA, the National Transportation Safety Board, the Consumer Product Safety Commission, the battery and airline industries, airline employee organizations, testing laboratories, and the emergency response communities to increase public awareness about battery-related risks and developments. These useful safety tips are highlighted at the public website:

For the extremely intrepid, you may read the actual final rule.pdf on It’s 22 pages long, so get a cup of coffee.

On the Safe Travel website (which is an arm of the DOT and PHMSA), more specific guidelines are provided than what was in the press release. Feel free to read Safe Travel’s synopsis.html as well if you like. It’s not too long.

For the record, I don’t think I’ve ever seen a primary lithium battery before. All of my lithium-based batteries are lithium ion, which are much less volatile and are subject to slightly different rules. I will presume that we’re only talking about lithium ion batteries from here on out.

The Concerns

The danger of having lithium batteries floating around in luggage is twofold. First, there is some concern about batteries getting shorted out and causing fires in the cargo hold where fire suppression is mechanized and not as effective as people in the cabin area with fire extinguishers. Second, if a lithium battery were to catch fire by some means, it is possible that it could explode. So you can imagine the DOT’s concerns.

Safe Travel’s release about these new rules is fairly specific about what sorts of batteries you can’t bring on the plane, but rather than parroting their website, I’ll break it down into the important bits.

The Rules

  • You really shouldn’t pack your spare batteries in your checked luggage because the TSA inspectors have the right (and yes, the responsibility) to remove them and throw them away if they believe them to be a safety hazard. At between $25 and $50 per battery, why take the risk?
  • These new rules do not set any quantity limitations on batteries containing fewer than eight “equivalent grams” of lithium. Basically, all of your batteries are likely to be excluded from this rule. I will get into the specifics below.
  • Batteries that are not lithium-based are definitely excluded from these rules. Make certain that you are aware of what your batteries are made out of. For example, the Canon EOS-1d, 1ds, 1d Mark II, and 1ds Mark II use nickel metal hydride (NiMH) batteries, so take as many as you want.

Let’s Do Some Math

What on Earth is eight equivalent grams of lithium? Well, the DOT says that eight equivalent grams of lithium are present in a battery with approximately 100 watt-hours (wh) of power. So, how much is that?

We can figure it out pretty easily. A standard Canon BP-511A battery (used by all Canon prosumer cameras such as the Rebel, 10D, 20D, 30D, 40D, 5D, and on, and on) is rated at 1,390 milliamp-hours (mAh), which means that if you pulled one milliamp of current out of the battery per hour, it would last for 1,390 hours. Another way to say it is that if you pulled 1,390 milliamps of current out of the battery, it would last for one hour.

We can convert 1,390 milliamps to watts by assuming a time period of one hour. Ahem, here is a formula:

W = V × A

Watts is equal to volts multiplied by amps. This battery is 7.4 volts and we’ll say it’s pushing 1,390 milliamps, or 1.39 amps.

W = 7.4V × 1.39A W = 10.286VA

Because we assumed a time unit of one hour, we can say that this battery has a power rating of roughly 10wh (10 watts × 1 hour). Making any sense?

Clearly 10wh is far below the 100wh rating necessary to reach eight equivalent grams of lithium, so it’s safe to say that our little BP-511A battery is pretty far away from being subject to these new rules. It’s really important to note that the DOT doesn’t care how many batteries you have that contain fewer than eight equivalent grams of lithium, nor do they care how much aggregate lithium there is in your carry-on. The concern is only for batteries with eight or more equivalent grams each.

Taking Precautions

Just because you’re a whiz kid with a calculator and you are functionally literate doesn’t mean that the TSA folks won’t hassle you if they feel like you aren’t being safe. So, to prevent unnecessary headaches, the Safe Travel website recommends the following important procedures:

  • Pack spare batteries in carry-on baggage. In the passenger compartment, flight crews can better monitor safety conditions to prevent an incident, and can access fire extinguishers, if an incident does happen.
  • For loose batteries, place tape across the battery’s contacts to isolate terminals. Isolating terminals prevents short-circuiting.
  • If original packaging is not available, effectively insulate battery terminals by isolating spare batteries from contact with other batteries and metal. Place each battery in its own protective case, plastic bag, or package. Do not permit a loose battery to come in contact with metal objects, such as coins, keys, or jewelry.

The first one echoes my intuition about keeping expensive batteries close as hand if possible, to keep an eye on them. The second and third points are of interest to me because I normally pack a couple of Canon-brand BP-511As as well as a handful of cheaper, third-party BP-511A lookalikes, which do not come with the handy plastic covers that would satisfy those suggestions.

Fortunately, there is a Yahoo! store called Green Batteries.html that is selling those little doodads for $1.77 (or four for about $5.50, which is about $1.40 each). I plan to pick up a bunch of those and make sure all of my batteries are properly insulated from external contact.

I travel with a Tamrac CyberPack, which has individual battery pockets in the outer compartment, but when it comes to TSA inspectors, I always give them the benefit of the doubt. For $10, it’s just peace of mind.

If any of you good folks fly with your gear in the coming months, please do write me with your experiences, positive or negative. Leave a comment on this post, or just drop me an email (aaron at singleservingphoto dot com), I’d love to hear from you.