Vietnam Airlines and Vietjet Air issued a notice asking passengers not to use power banks during the flight and to leave them in a position that is easy to observe.
According to the airlines’ notices, power banks must not be left in checked baggage, must be removed from carry-on baggage, must be placed in a place that is easily visible next to passengers, and absolutely must not be used or charged with any electronic devices during the flight journey, including during take-off and landing. Do not charge the power bank from the aircraft’s USB port.
Each battery needs to be individually protected and turned off completely, avoiding activation. “All batteries and equipment transported are for personal use only,” Vietnam Airlines wrote in the statement.

Previously, airlines only required passengers not to leave power banks in checked baggage, but there were no regulations on their use on airplanes.
A power bank is a small, convenient device designed to charge and power mobile devices such as phones, laptops, tablets, and wireless headphones. The power bank as a portable power outlet can be carried anywhere, especially necessary for business trips and travel. Some other notes: each passenger is only allowed to carry a maximum of 10 batteries with a capacity of not more than 100 Wh. For a universal power bank with a voltage of about 5V, the corresponding capacity in mAh will be about 20,000. For power banks with a capacity of 100 to 160 Wh, passengers are allowed to bring up to two devices.
The power bank must be packaged in the same box as when it was first purchased or insulated. The terminals must be insulated with adhesive tape or a special protective bag to prevent short circuits. Charging must have a clear source, power, and capacity information.
In addition to Vietnam, Singapore Airlines will also prohibit passengers from using power banks on flights from April 1. Thai Airways, Air Asia, and many other airlines have also issued similar regulations. South Korea‘s Air Busan prohibits passengers from leaving power banks in the baggage compartment on their seats.