18650, 2gram lithium quanity restrictions

Planning to fly with flashlights and some spare batteries.

100mW restriction is no brainer to calculate and prove in security check, but how about amount on lithium metal in each battery?

Limit seem to be 2 grams per battery. Even this does not mention actual weight. Using Samsung 30Q.


Lithium ion batteries don’t have lithium metal in them. Which is also why they considered safe for landfills. Not that one shouldn’t toss them in a recycle bin.

Hmm. But INR = LiNiMnCoO2 ?

Still produces lithium ions, but has no lithium metal

Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2 or NMC) (LiNiMnCoO2 or NMC)

One of the most successful Li-ion systems is a cathode combination of nickel-manganese-cobalt (NMC). Similar to Li-manganese, these systems can be tailored to serve as Energy Cells or Power Cells. For example, NMC in an 18650 cell for moderate load condition has a capacity of about 2,800mAh and can deliver 4A to 5A; NMC in the same cell optimized for specific power has a capacity of only about 2,000mAh but delivers a continuous discharge current of 20A. A silicon-based anode will go to 4,000mAh and higher but at reduced loading capability and shorter cycle life. Silicon added to graphite has the drawback that the anode grows and shrinks with charge and discharge, making the cell mechanically unstable.

The secret of NMC lies in combining nickel and manganese. An analogy of this is table salt in which the main ingredients, sodium and chloride, are toxic on their own but mixing them serves as seasoning salt and food preserver. Nickel is known for its high specific energy but poor stability; manganese has the benefit of forming a spinel structure to achieve low internal resistance but offers a low specific energy. Combining the metals enhances each other strengths.

NMC is the battery of choice for power tools, e-bikes and other electric powertrains. The cathode combination is typically one-third nickel, one-third manganese and one-third cobalt, also known as 1-1-1. This offers a unique blend that also lowers the raw material cost due to reduced cobalt content. Another successful combination is NCM with 5 parts nickel, 3 parts cobalt and 2 parts manganese (5-3-2). Other combinations using various amounts of cathode materials are possible.

Battery manufacturers move away from cobalt systems toward nickel cathodes because of the high cost of cobalt. Nickel-based systems have higher energy density, lower cost, and longer cycle life than the cobalt-based cells but they have a slightly lower voltage.

Alrighty. Thank You!


Makes me wonder why such restriction exist. What are battery types that actually have lithium inside?

Chances are even the average BLF’er knows more about lithium ion batteries than the people who come up with those restrictions.

The 100Wh rule is pretty pointless because you can have 1,000Wh of LiFePo4 and 20Wh of high discharge LiPo, and guess which one is more volatile and dangerous.

You shouldn’t have any problems with the lights or batteries. I flew to Iceland and Ireland last December with my family and I had 4 spare 18650’s in plastic carriers, 3 18650 light with the batteries in them, and a 2 cell 18650 power bank. With connections and the international flights all I boarded 6 times and never was asked about the batteries and lights in my carry-on.

I fly several times a year domestically and internationally and have never been questioned.

Like SIG says, plastic cases for spares. I use the silcone holders and plastic cases taped shut. No problem with the airlines as long as you carry them on and not in checked baggage.

USPS uses lithium content restrictions for NONRECHARGEABLES, here’s what they say about it:

“c. Lithium metal cell or battery means an electrochemical cell or battery utilizing lithium metal or lithium alloys as the anode. The lithium content of a lithium metal or lithium alloy cell or battery is measured when the cell or battery is in an undischarged state. The lithium content of a lithium metal or lithium alloy battery is the sum of the grams of lithium content contained in the component cells of the battery. These batteries are also referred to as primary or nonrechargeable lithium cells or batteries, and are often used in consumer products such as cameras and flashlights.”

Publication 52 Revision: New Mailing Standards for Lithium Batteries