Up to two power banks in the cabin: Vietnam's new rule from July

On overseas trips where your phone's battery is uncertain, a power bank is an indispensable partner. But from July 1, 2026, the rules for carrying one became a notch more detailed on all flights departing from, arriving in, or transiting Vietnam. The new standard set by the Civil Aviation Authority of Vietnam (CAAV) goes as far as the number per person, capacity, where to place it, and whether it can be used, covering not just Japan–Vietnam flights but every traveler on domestic flights like Hanoi to Da Nang. Proceed to security screening without knowing, and you may be made to open your bag or, at worst, be unable to check it there. We've organized the key points so people going to have fun from Japan don't get held up at the airport.

What changed on July 1

The new rules CAAV enforced on July 1 rest on four main pillars. First, each passenger may bring a maximum of two power banks into the cabin. Second, the capacity is in principle 100 watt-hours (Wh) or less by rated energy. Third, they must go in your carry-on baggage (they cannot go in checked baggage). And fourth, during the flight both using the battery itself and charging a phone or the like from it are prohibited.

Batteries over 100Wh and up to 160Wh may still be brought aboard if you get the airline's prior approval before the flight. For lithium-metal battery types, a separate standard of no more than 2 grams of lithium content applies. The CAAV explains that this measure reflects the guidelines on air transport of dangerous goods set by the International Civil Aviation Organization (ICAO).

The "no use" rule is actually from last year; this time it covers the number and where you put them too

That you can't use a power bank in flight isn't itself new. Major carriers such as Vietnam Airlines and VietJet Air had already banned in-flight use and charging as of March 2025. The origin is the string of lithium-ion battery fire incidents in various countries, with the concern that smoke inside an overhead bin would be noticed too late.

The new July rules take this trend a step further, unifying operations that had varied by airline into an authority-wide standard. What's new is that they cap the number you can carry on at "two," clearly ban stowing them in checked baggage, and even require them to be "placed where they're visible, such as around your seat." Rather than tucked in the overhead bin, they're to be kept where cabin crew can check them right away - in the pouch under the seat in front or on your own lap.

How many Wh is your battery? A conversion guide

Even told '100Wh or less,' many commercial power banks are labeled in milliamp-hours (mAh), so it may not click. As a rough guide, using a typical output voltage of 3.7V, you can estimate with Wh = mAh x 3.7 / 1000. Applying this formula gives the table below.

The "26,800 mAh" often seen in commercial high-capacity models is about 99 Wh by this conversion, a level that sits right up against the 100 Wh cap. In practice, many products have the Wh figure printed on the unit by the maker, so it's reassuring to check the marking on the back of your battery once before traveling. A battery whose figures can't be read, or have peeled off and become unclear, can be a source of trouble.

How locals and travelers receive it

In Vietnam's Japanese-resident community, while many say from before enforcement that "two is enough for ordinary travel," those on family trips where one person carries everyone's batteries together voice puzzlement that "we'll have to split them up." From seasoned travelers who connect between domestic flights, there's also a calm take: "The use ban is already established, so all that's left is checking the capacity marking."

Vietnamese airlines too have been instructed by the authorities to make the requirements known to passengers before boarding, and announcements at check-in and the gate are expected to increase. Local media likewise repeatedly report the fire risk in overhead bins, with coverage centering on framing the “keep it in sight” rule positively as a safety measure.

So Japanese travelers aren't stopped at the airport

This new rule trips up the start of your trip in the form of "being held up at security or the boarding gate" before any question of fines. The practical points to keep in mind when heading over from Japan are as follows.

• Limit the power banks you carry to two, and check the capacity marking (Wh or mAh) before departure.
• Don't put them in checked baggage such as a suitcase; always move them to your carry-on bag.
• To prevent short-circuiting of the terminals, protect it by one of the following: putting it in its original box, covering the terminals with tape, or separating it into an individual plastic bag or pouch.
• In the cabin, don't stow it deep in the overhead bin; keep it somewhere visible, like the seat-back pocket or on your lap. Don't charge during the flight.

This revision is also one of a string of rule changes in Vietnam's travel environment since the start of July. Changes that affect the real lives of travelers and residents, such as entry procedures and taxation, overlap in the same period, so checking them together before you travel makes planning easier. On the revival of the health declaration,Health declarations return for entry to Vietnam from July, adding one more thing to do before departureand the consolidation of immigration procedures into VNeID isFrom June, Vietnam's immigration procedures are consolidated into VNeIDcompiles the details.

Ripple effects on the aviation industry and market

Regulation of lithium-ion batteries in air transport is not Vietnam’s move alone. Centered on ICAO guidance, airports and airlines across Asia have tightened carry-on conditions one after another. Vietnam spelling out the number, capacity, and placement as an official standard is in line with the standardization advancing across the whole region. For travelers, the nuisance of slightly different rules by destination remains, but remembering one combination — “two units, 100 Wh, carry-on, in sight” — will keep you out of trouble on Vietnam flights for the time being.

Added domestic flights are also expected in Vietnam this summer, and as more travelers loop through multiple cities, the chances of running into a battery check on domestic flights rise accordingly. Those planning a multi-city loop should pack on the assumption that the same rule applies on every connecting flight. For trends in summer flights,Vietnam’s domestic flights ramp up sharply this summer: when seats get easier to grab and how to bookis also a helpful reference.

Summary and next step

Vietnam's new rules from July 1, 2026 boil down to five points: power banks are two per person, 100 Wh or less, in your carry-on, in a visible place in the cabin, and not used in flight. No difficult procedures are needed; just check the number and capacity marking of your batteries before traveling and move them from checked baggage to your cabin bag, and most travelers can pass through as is. Check the Wh marking on the back of your battery once at the packing stage, not right before the trip. This is the surest preparation for not getting held up at the airport.

Sources

• VnExpress "From July 1, passengers may bring up to two power banks into the cabin"
• Vietnam News: Power banks must be kept in carry-ons during flights from July
• Vietnam Plus: Air travellers required to keep power banks in carry-on bags from July
• VIETJO Vietnam News: tighter rules on power banks in aircraft cabins; use and charging banned from July