Batteries on a Plane: the Rules for Your Dive Gear
Before every flight, the same question comes up, which batteries are allowed in the cabin and which must stay grounded. This calculator converts your battery capacity into watt-hours and tells you, model by model, what airlines accept.
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Why these limits exist
Lithium-ion battery restrictions on flights are not arbitrary. They stem from real incidents where faulty batteries caused cargo hold fires, in an environment impossible to reach mid-flight.
The phenomenon is called thermal runaway. A damaged or short-circuited lithium-ion cell can reach 600°C in seconds, igniting neighbouring cells in a cascade. In the cabin, crew can intervene. In the cargo hold, nobody can act before landing.
The 100 Wh threshold corresponds to the capacity below which thermal runaway risk remains statistically manageable. Between 100 and 160 Wh, the airline assesses case by case. Above that, the stored energy is considered too high for commercial passenger aircraft.
For an underwater photographer, the math is straightforward. Your camera battery (7.2V, 2000 mAh = 14.4 Wh) is well below the limit. Strobe batteries (Inon Z-330: 7.2V, 2550 mAh = 18.4 Wh) too. The real watch points are high-capacity powerbanks and video light batteries, which can approach or exceed 100 Wh.
Frequently asked questions
What size battery can I bring on a plane for underwater photography?+
Most airlines accept lithium-ion batteries up to 100 Wh in cabin baggage. Between 100 and 160 Wh, prior approval is often required. Above 160 Wh, transport is generally prohibited.
Can I put my underwater strobe batteries in checked luggage?+
No. Spare lithium-ion batteries must always be carried in cabin baggage with terminals protected. Strobes with built-in batteries can go in checked luggage if the battery cannot be removed.
How do I calculate the Wh of my camera battery?+
Multiply voltage (V) by capacity (Ah). For example, a 7.2V 2000 mAh battery = 7.2 x 2.0 = 14.4 Wh. Our built-in calculator does this automatically.
Are IATA rules the same for all airlines?+
IATA rules define a minimum framework, but each airline can apply additional restrictions. Some limit the number of batteries, others impose thresholds below 100 Wh.
How many spare batteries can I take on a dive trip?+
The number varies by airline. IATA rules generally allow up to 20 batteries under 100 Wh. Some airlines limit to 2 batteries between 100 and 160 Wh.