There have been threads on power-banks getting confiscated by security at BKK when exiting before Immigration.

I used to have a couple of 10,000 mAh power-banks - they were regularly inspected and passed muster.

I thought that 10,000 mAh or 15,000 mAh might be the limit - however, international regulations state the limit is not on the capacity (electrical storage measured in mAh - milliamp-hours - i.e. whats in the tank) but on the the actual voltage Wh (Watt-Hours) and that limit is < 100 Wh

Conundrum:

I have a decent power-bank (Anker)

It has a 25,000 mAh capacity

It can charge devices at a power of up to 165W across ports (i.e. 100W to a laptop and 65W to a iPad or Phone)

Interval voltage is 3.6v

Total Energy 90 Wh

The power-bank is safe for travel across Europe etc - but Thailand can be its own beast in applying regulations to its own misunderstanding.

Thus: anyone have any real world experience with travelling with larger power banks...

25000 mAh and < 100 Wh ??

20 minutes ago, richard_smith237 said:

I have a decent power-bank (Anker)

Totally of topic I know but do you have a supply source/tech description as it sounds like just what I need?

2 hours ago, scottiejohn said:

Totally of topic I know but do you have a supply source/tech description as it sounds like just what I need?

Here's the info - I'm just hoping Thai security wouldn't try and take it off me as its extremely useful for long haul travel.

Copy and paste from Anker site:

Triple 100W USB-C Ports for Multi-Device

Designed for multitaskers, featuring three USB-C ports each delivering up to 100W, allowing you to power a MacBook and other devices simultaneously without losing charging speed.

25,000mAh for Long-Haul Power

Set off on extended journeys with a huge 25,000mAh capacity that supports your devices through multiple uses, complete with 100W ultra-fast recharging that fuels the power bank to 30% in just 20 minutes.

Dual Built-In Cables for On-the-Go Use

Equipped with two USB-C cables, one extendable up to 2.3 ft for over 20,000 retractions, and another at 0.98 ft that acts as a durable carrying strap capable of enduring more than 20,000 bends.

This one is by Anker:

https://www.anker.com/uk/products/a1695-anker-power-bank-25000mah-165w

Lazada Link:

Anker พาวเวอร์แบงค์สำหรับแล็ปท็อป, เครื่องชาร์จพกพา 25,00...

พาวเวอร์แบงค์สำหรับแล็ปท็อป Anker 25000mAh พร้อมพอร์ต USB-C 3 พอร์ต 165W ชาร์จพกพาได้หลากหลายอุปกรณ์ รองรับ iPhone 17/16/15, MacBook, Samsung และอื่นๆ ด้วยสายชาร์จในตัวและสายดึงได้ รับประกันนาน 18 เดื

UGREEN also have their equivalent:

https://uk.ugreen.com/products/ugreen-nexode-power-bank-25000mah-200w

Lazada Link:

UGREEN Nexode 20000mAh 130W / 25000mAh 200W Fast Charging...

UGREEN

Security took a power bank from me in the Philippines 2 years ago, since then I only buy equipment with Wh rating listed on the unit.

I bought a Lenovo Go with 20.000 mAh, but has 77Wh listed on the the back side.

It suits all my needs and I like; the form factor which fits perfectly in laptop bag pocket, weight (390g) + the cable is pushed into and locked in the power bank.

[Instalments 0% 6 D. (Days) Lenovo Go Usb-C Power Bank 20000 Mah (40Allg2Www) / 1 Year Warranty | Lazada.co.th

It only has 65W power delivery but easily charges my laptop on the go and I have never been in need of more capacity.

Recommend buying power banks / batteries with Wh listed on the unit. The security in Asia can be difficult/impossible to convince by calculating the Wh by mAh and voltage.

I'd add that, if you're flying to China, you need one with a CCC rating. Not a CE, or any others.

That's a recent change, added within the last year.

Here's how to do it :)

I have a 130W power bank to deliver 20 volts to my laptop, and I have another 130W power bank that delivers 5 volts to my 4 mobile phones and LED light (I teach online in Myanmar, where mains electricity is somewhat lacking...).

When I take my power banks on a plane, I also take a paper copy of the advert in Thai for these devices, which highlights the power rating...... which strangely does not match that original advert and is less than 100 watts lol.

(Thanks Photoshop)

20 hours ago, richard_smith237 said:

but on the the actual voltage Wh (Watt-Hours) and that limit is < 100 Wh

It's energy (joules/ J) not voltage.

1 watt = 1 joule/ second

1 hour = 3600 second

1 watt hour = 3600 joule x second/ second = 3600 J

100 Wh = 360,000 J (10% of a unit of electricity as it happens)

21 hours ago, richard_smith237 said:

25000 mAh and < 100 Wh ??

25000mAh is < 100 Wh.

The unit of mAh is coulomb [units of ampere = coulomb/ second, unit of hour = second, so (coulomb/ second) x second = coulomb]

You have to convert the mAh to joules

25000 mAh = 25 Ah.

Power in watts (J/s) = V x A

At 1 V 25000 mAh would be 25 W for one hour or

25 x 3600/ 1000 = 90 kJ

100 Wh = 100 x 3600/ 1000 = 360 kJ (which is >90 kJ)

1 hour ago, BeastOfBodmin said:

25000mAh is < 100 Wh.

The unit of mAh is coulomb [units of ampere = coulomb/ second, unit of hour = second, so (coulomb/ second) x second = coulomb]

You have to convert the mAh to joules

25000 mAh = 25 Ah.

Power in watts (J/s) = V x A

At 1 V 25000 mAh would be 25 W for one hour or

25 x 3600/ 1000 = 90 kJ

100 Wh = 100 x 3600/ 1000 = 360 kJ (which is >90 kJ)

Thanks... I'm aware the Power Bank is within the Internationally recommended limit of < 100 Wh

My Anker states: 90Wh (photo below)

The power-bank falls within internationally accepted limits - however, after having my own 10,000 mAh powerbank checked previously (numerous times) it appears they were very hot on the limit and I witnessed people having their power-banks confiscated - even though they 'appeared' like standard 10,000 mAh units (perhaps because the labelling was missing or poor).

I'm wondering if security would misunderstand the 165W label on the side and I then get into discussion with them about 165w (large labelling) Vs 90Wh (tiny specks on the base).

Has anyone travelled through BKK security with large 25,000 mhA / < 100 Wh power-banks regularly ?

Dealing with halfwits who have the power to 'confiscate' items while half knowing a regulation and applying their misinterpretation is not something I'm fond of - I've encountered that in the past having baby milk confiscated when travelling with an infant (UK security - stubbornly standing their ground - confiscating baby milk even as I quoted their own regulations to them)

Here is the latest update on rules - curtesy of Gemini:

Navigating airport security in Thailand with electronics is generally straightforward, provided you know the specific thresholds. For a 25,000 mAh power bank, you are within the "safe" zone, but there are new 2026 regulations regarding how you use it.

Here is the breakdown for exiting Thailand (Suvarnabhumi, Don Mueang, Phuket, etc.) as of April 2026:

1. Capacity Limits (The 100Wh Rule)

Airlines and Thai airport security (AoT) measure power banks in Watt-hours (Wh), not mAh. For a standard 25,000 mAh power bank:

• The Math: Most power banks operate at 3.7V. $25,000 \text{ mAh} \times 3.7\text{V} / 1000 = \mathbf{92.5\text{Wh}}$.

• The Verdict: Since this is under 100Wh, it is internationally accepted and allowed in your carry-on luggage without needing prior airline approval.

Capacity (mAh)	Watt-hours (Wh)	Thai / International Status
Under 20,000	Under 74Wh	Allowed (Unrestricted)
20,000 – 32,000	74Wh – 118.4Wh	Allowed (Limit: 2 per person)
Over 32,000	Over 118.4Wh	Often confiscated / Requires Approval

2 hours ago, simon43 said:

Here's how to do it :)

I have a 130W power bank to deliver 20 volts to my laptop, and I have another 130W power bank that delivers 5 volts to my 4 mobile phones and LED light (I teach online in Myanmar, where mains electricity is somewhat lacking...).

When I take my power banks on a plane, I also take a paper copy of the advert in Thai for these devices, which highlights the power rating...... which strangely does not match that original advert and is less than 100 watts lol.

(Thanks Photoshop)

Good idea - perhaps the way to be sure is to have a print out of the specs and a print out of the international regulations ( though that feels like overkill )...

... usually I travel so much that I don't sweat this stuff - but recently there has been a lot of disruption to travel which can take the 'duration' over the usual 'battery timespan' of my devices (noise cancelling headphones, iPad and laptop - + ensuring phone always has a solid amount of charge for any 'destination requirements' - translator Apps / and important online access etc.

Utimately - I'm not bothered about any of it - a $100 power-bank can be replaced - its just the annoyance of getting one confiscated at Thai Security because they don't understand the regs which would bug me.

So - if people are regularly travelling with 25,000 mAh power-banks (that are <100Wh) - thats a good thing.

And I'd hope the Thai security don't pick up on the large 165W label on the side and get mixed up.

9 hours ago, THEN said:

It only has 65W power delivery but easily charges my laptop on the go and I have never been in need of more capacity.

Recommend buying power banks / batteries with Wh listed on the unit. The security in Asia can be difficult/impossible to convince by calculating the Wh by mAh and voltage.

Thats the concern - convincing people with a dash of power that they may misunderstand their own rules !!!

The 90Wh is clearly labelled on the base - IF you have superhuman eyesight !!!

And that clearly also depends on security understanding the difference between Watts (W) and Watt Hours (Wh).