Staying connected while traveling is nice, so power banks have become an indispensable travel companion. If you’re planning to fly with a power bank in your carry-on luggage, there’s one little rule that you need to know… That’s the 100-watt hour (Wh) limit imposed by airlines worldwide. But what does this limit mean, and how can you ensure your power bank complies?
The Rationale Behind the 100-Watt Hour Limit
The 100 Wh limit for lithium-ion batteries is enforced as part of airline safety regulations designed to minimize the risks of battery overheating and fires during flights.
Lithium-ion batteries are known for their energy density, which makes them both powerful and potentially hazardous if not properly managed. By capping the maximum allowable capacity, airlines aim to reduce the risk of incidents in the confined environment of an aircraft.
Deciphering Your Power Bank’s Capacity
You may encounter a challenge when trying to determine if your power bank is within the legal limit because manufacturers sometimes list capacity in milliampere-hours (mAh) rather than watt hours. To navigate this, you’ll need to convert mAh to Wh, a simple process that involves a little math.
Here’s the formula you’ll need:
Watt Hours (Wh) = Milliampere Hours (mAh) x Voltage (V) / 1000
Typically, most power banks operate at a voltage of 3.7 volts. To illustrate, if your power bank is rated at 20,000 mAh, the calculation would be:
20,000 mAh x 3.7 V / 1000 = 74 Wh
Since 74 Wh is below the 100 Wh limit, this power bank is safe to take on board.
Checking Your Power Bank Before You Fly
- Find the Specifications: Look for the technical specifications on your power bank, usually listed on the device itself or the packaging. This will include the capacity in mAh and the voltage.
- Calculate the Watt Hours: Use the formula provided to convert mAh to Wh.
- Compare with the Limit: Ensure the calculated Wh is below 100. If it’s higher, you may need to leave this power bank at home or find an alternative.
What If Your Power Bank Exceeds 100 Wh?
For larger power banks exceeding 100 Wh but below 160 Wh, special permission from the airline is required, and they are typically limited to a maximum of two per passenger. Power banks over 160 Wh are prohibited from being carried on flights altogether.
Why It Matters
Adhering to these regulations is not just about compliance… It’s about safety. Incidents involving lithium-ion batteries are rare, but can pose serious risks to passengers and crew. By understanding and respecting these limits, you contribute to safer skies.
