Never charge a power bank from the seat outlet
Industry dangerous goods guidance prohibits recharging portable batteries from aircraft power, and the reasoning is about how lithium cells fail.
It is one of the least known rules in the cabin and one of the easiest to break without realising: you may not recharge a power bank from an aircraft's seat outlets. Not the 110V socket, and not the USB port.
The prohibition sits in industry dangerous goods guidance and is enforced by a growing number of carriers directly.
The distinction that matters
There are two directions of power flow, and only one of them is restricted:
- Power bank → your phone. Permitted. This is the normal use of the device.
- Aircraft outlet → power bank. Prohibited. This is charging the battery itself.
The rule is about the second case only.
Why charging is the risky part
A lithium cell is under the greatest internal stress while it is being charged. Current is being forced into the cell, heat is being generated, and any manufacturing defect or existing damage is most likely to become a failure at precisely that moment.
Battery incidents cluster around charging. A cell sitting idle is stable in a way a cell absorbing current is not.
Add to that the electrical environment. Aircraft seat power is not a domestic wall socket. It is a converted supply with different characteristics, subject to interruption, and it is shared across a bank of seats. Feeding that into a battery management system designed for household mains introduces a variable nobody wants introduced at altitude.
The practical consequence
On a long flight, this means the power bank you board with is all you have. It cannot be topped up en route.
Plan the capacity, not the top-up
- Charge everything fully before you leave for the airport.
- Use airport charging during a layover — that is where topping up is meant to happen.
- Size your power bank for the whole journey, including delays, rather than for the flight alone.
- Use the seat outlet for your devices directly — that remains entirely permitted and is the better use of it anyway.
The cabin crew's position
Crew are trained to spot this and will ask you to stop. It is worth understanding that this is not a discretionary policy they are choosing to enforce — it sits in the same category of rules as the ban on checked carriage, and they have no latitude on it.
The broader shift
Battery rules have tightened steadily as the number of lithium cells per passenger has climbed. A traveller two decades ago carried one battery; a traveller today may carry a phone, a laptop, headphones, a watch, a camera, a drone and two power banks.
The regulations are catching up to that, and the direction is consistently towards fewer batteries, kept closer, and left alone in flight.