What Is UN 38.3, and Why Does It Matter for CPAP Batteries?

If you’re planning to fly with a CPAP battery, you may come across terms such as UN 38.3 certification, UN 38.3 form, or UN 38.3 test summary.

They all refer to the same basic issue: whether a lithium battery has completed the safety testing required for transportation.

That matters because most portable CPAP batteries use lithium cells. When you bring one on a plane, the airline may want to confirm the battery’s capacity and whether it has been tested for air transport.

Here’s what UN 38.3 means, what paperwork you may need, and how the rules apply to EXP PRO batteries.

What is UN 38.3?

UN 38.3 is a section of the United Nations Manual of Tests and Criteria that covers the transportation of lithium cells and batteries.

Before a lithium battery can be offered for transport, its design must pass a series of safety tests. These tests simulate conditions a battery may experience while being shipped by truck, ship, or aircraft.

The testing can include:

• Altitude simulation

• Thermal testing

• Vibration

• Shock

• External short circuit

• Impact or crush testing

• Overcharge testing

• Forced discharge testing

You don’t need to know the details of each test when you travel. What matters is that UN 38.3 documentation shows the battery design has completed the required transportation-safety testing.

This applies to many lithium battery products, including CPAP batteries, power banks, camera batteries, medical equipment batteries, and rechargeable electronics.

Is it really a “UN 38.3 certificate”?

People often use several names for the paperwork:

• UN 38.3 certificate

• UN 38.3 form

• Lithium battery certificate

• Battery travel document

• Airline battery document

The more accurate term is usually UN 38.3 test summary.

A test summary contains information about the battery, its manufacturer, the testing laboratory, and the test results. According to PHMSA, lithium cells and batteries offered for transportation must have passed the applicable design tests in Section 38.3 of the UN Manual of Tests and Criteria. Manufacturers must also make the test summary available upon request.

So, while travelers commonly ask for a “UN 38.3 certificate,” the document they are usually looking for is the battery’s test summary.

Do you need a UN 38.3 test summary to fly with a CPAP battery?

You may never be asked to show a UN 38.3 test summary at the airport. We still recommend keeping a copy available when you travel with a CPAP battery.

CPAP batteries are often larger than ordinary phone chargers and small power banks. If an airline employee or security officer has questions, having the battery specifications and transport documentation ready can save you from trying to explain everything at the counter.

This is especially useful when the battery is rated between 101Wh and 160Wh, since batteries in that range generally require airline approval before travel.

Save a digital copy of the test summary on your phone. Bringing a printed copy is also a good idea, particularly for international travel.

UN 38.3 testing is not the same as airline approval

This is the distinction that causes the most confusion.

UN 38.3 documentation relates to transportation-safety testing.

Airline approval determines whether your specific battery can be brought aboard a passenger flight.

A battery can have complete UN 38.3 documentation and still require airline approval. Its watt-hour rating, how it is packed, and the airline’s own policy all still matter.

Passenger-airline rules are generally divided into three battery sizes:

Battery capacity	General airline rule
100Wh or less	Usually allowed in carry-on luggage
101Wh to 160Wh	Airline approval is usually required
Over 160Wh	Generally not allowed on passenger aircraft

Always check with your airline before traveling. Individual airlines may have additional procedures, documentation requirements, or limits.

What paperwork should you bring?

You probably won’t need to show every document in your travel folder. The goal is simply to have the information available if someone asks.

We recommend bringing:

• The battery’s UN 38.3 test summary

• A specification sheet showing the battery’s watt-hour rating

• Written airline approval for batteries over 100Wh

• Your CPAP prescription or a doctor’s note, especially for international travel

• Information about your CPAP machine if you plan to use it during the flight

Keep the documents together on your phone and consider printing a copy. Airport Wi-Fi and cell service are not always reliable, and screenshots are easier to pull up quickly than website links.

Does the EXP48PRO APEX have UN 38.3 documentation?

Yes. UN 38.3 travel documentation is available for the EXP48PRO APEX.

The EXP48PRO APEX has a capacity of 153.6Wh. That keeps it below the general 160Wh passenger-airline limit, but it is still above 100Wh. You should contact your airline before your trip and request approval to carry it onboard.

The battery should be packed in your carry-on luggage, not in a checked bag. Protect the ports from accidental contact and keep the airline’s written approval with your other travel documents.

Download the EXP48PRO UN 38.3 test summary

Before traveling with an EXP PRO CPAP battery, download the battery documentation and save it somewhere you can access without an internet connection.

Most travelers will never be asked to show it. But if an airline employee has questions about the battery, you’ll be able to provide its capacity and transportation-safety information immediately.

Download the EXP48PRO UN 38.3 documentation

Which EXP PRO battery can you fly with?

The EXP48PRO APEX and EXP96PRO APEX are built for different types of travel.

EXP48PRO APEX

The EXP48PRO APEX is 153.6Wh and may be carried on a passenger aircraft with airline approval.

It is the EXP PRO option for airline travel, CPAP use away from home, and trips where a compact battery is needed.

EXP96PRO APEX

The EXP96PRO APEX is over 160Wh and is not intended for passenger airline travel.

It is better suited for:

• Camping

• RV and camper-van travel

• Road trips

• Off-grid CPAP use

• Emergency home backup

Having UN 38.3 documentation does not override the airline watt-hour limit. Because the EXP96PRO is over 160Wh, it should not be treated as a passenger carry-on battery.

What should you say when contacting the airline?

You can use the message below when requesting approval:

Hello, I use a CPAP machine and will be traveling with a lithium CPAP battery in my carry-on bag. The battery is rated at 153.6 watt-hours, which is below the 160Wh limit. I understand that batteries between 101Wh and 160Wh require airline approval. UN 38.3 transportation-safety documentation is available for the battery. Can you please confirm that I have approval to carry it onboard?

Ask the airline to respond in writing. Save that response on your phone and print a copy for your travel documents.

It also helps to include:

• Your flight number

• Your travel date

• The battery brand and model

• The exact watt-hour rating

• Confirmation that the battery will remain in your carry-on luggage

What to check before flying with a CPAP battery

UN 38.3 documentation is useful, but it is only one part of preparing for your flight.

Before leaving, confirm:

• The battery’s watt-hour rating

• Whether airline approval is required

• That the battery will be packed in your carry-on

• That the ports are protected from short circuits

• That you have the correct cord for your CPAP machine

• Whether your airline has any additional battery or medical-device rules

For EXP PRO customers, the EXP48PRO APEX is the airline-travel option. Its 153.6Wh capacity falls below the general 160Wh limit, but airline approval is still required because it is over 100Wh.

Contact the airline before your flight, carry the battery onboard, and keep the approval and UN 38.3 documentation where you can easily reach them.