The Assist PLUS Small 4.2Ah Battery was designed to provide a lighter battery option and, importantly, to make travelling with your Assist PLUS possible.

With a rated capacity of 120.96 Wh, the Small Battery falls within the 100–160 Wh lithium-ion battery category used in current airline dangerous-goods regulations.

Batteries in this category may be permitted on passenger aircraft with airline approval, but they must be carried in carry-on baggage only and individually protected against short circuits. Current CASA guidance limits passengers to no more than two spare batteries in this category. Airlines may impose stricter requirements.

Always contact your airline before travelling. Airline approval is required for batteries over 100 Wh, and the airline has the final say on whether your batteries can be carried.

The Small 4.2Ah Battery is the only Assist PLUS battery designed to fall within the passenger-aircraft battery limits.

Batteries over 160 Wh are generally prohibited from passenger baggage and must be transported separately as dangerous goods cargo.

Before You Travel

Do not arrive at the airport without first checking with your airline.

Airlines can apply restrictions that are more stringent than the general IATA and national aviation requirements. Requirements can also vary between airlines on connecting itineraries.

Before travelling:

1. Contact every airline on your itinerary.
2. Tell them you are travelling with 120.96 Wh rechargeable lithium-ion batteries.
3. Confirm how many batteries they will permit.
4. Obtain any required prior approval.
5. Confirm their requirements for packaging, State of Charge and terminal protection.
6. Keep any required approval or correspondence with your travel documents.

IATA specifically advises passengers to check with their airline for batteries over 100 Wh because airline requirements can differ.

How Many Small Batteries Can I Take?

Under current CASA guidance, spare rechargeable lithium-ion batteries over 100 Wh but not exceeding 160 Wh:

• Require airline approval.
• Must be carried in carry-on baggage only.
• Are limited to two spare batteries per passenger.
• Must be individually protected against short circuits.

Therefore, the current general allowance for the 120.96 Wh Small Assist PLUS Battery is up to two spare batteries per passenger, subject to airline approval and any additional airline restrictions.

Do not assume your airline will accept two batteries. Always confirm before travelling.

How to Pack Your Small Batteries

Each battery must be individually protected against accidental short circuit and physical damage.

We recommend:

• Carrying each battery in its own protective LiPo/battery bag or protective pouch.
• Covering the charge and discharge terminals with electrical tape or otherwise insulating them.
• Keeping batteries separated from metal objects such as keys, tools and other equipment.
• Keeping the batteries where they can be easily removed for inspection.
• Keeping the battery's Foil Drive label clearly visible, including the 120.96 Wh rating.

IATA and CASA both require spare lithium batteries to be protected against short circuits. Acceptable methods include original packaging, insulating terminals with tape, or placing each battery in its own protective pouch or case.

Never place a spare Small Battery in checked baggage.

Spare lithium batteries must remain in the passenger cabin. If your carry-on bag is taken at the gate and placed in the aircraft hold, remove the batteries and keep them with you in the cabin.

Battery State of Charge

Individual airlines may impose their own State of Charge requirements.

Always follow the requirements provided by your airline.

If your airline specifies a maximum State of Charge, ensure your batteries are discharged to the required level before travelling.

Inspect Your Batteries Before Travel

Before packing your batteries, inspect each one carefully.

Do not travel with a battery that is damaged, swollen, leaking, punctured, overheating or otherwise compromised.

Check:

• Battery casing
• Heat-shrink covering
• Connectors
• Power leads
• Labels and Wh rating
• Any signs of impact or water damage

Damaged or recalled lithium batteries should not be carried on passenger aircraft because of the risk of overheating or thermal runaway.

Bring Your Battery Documentation

Airport security or airline staff may ask for information about your batteries.

We recommend travelling with:

• The Small 4.2Ah Battery Safety Data Sheet (SDS).
• Foil Drive battery specifications.
• Your airline approval or confirmation, where applicable.

Having the battery specifications and documentation available can make the screening process easier.

Can I Travel With the Foil Drive System?

The battery is the component subject to the lithium-ion battery restrictions.

For travel, we recommend packing the Foil Drive Electronics Box, motor, mast and other equipment separately from the batteries.

Foil Drive equipment such as foils, propellers, tools and other sharp components should be packed according to the airline and airport security requirements and are generally better suited to checked baggage.

Never pack spare lithium batteries in checked baggage.

Using the Parallel Y Lead

The Parallel Y Lead allows two Small 4.2Ah Assist PLUS Batteries to be connected together for use with the Assist PLUS.

Two Small Batteries provide a combined capacity equivalent to the Medium 8.4Ah Assist PLUS Battery.

Important Y Lead Rules

The Parallel Y Lead is ONLY compatible with two Small 4.2Ah Assist PLUS Batteries.

When using the Y Lead:

1. Only connect two Small 4.2Ah Assist PLUS Batteries.
2. Both batteries must be charged individually to 100% State of Charge before connecting them together.
3. Never charge two batteries while they are connected with the Y Lead.
4. Disconnect the Y Lead and charge each battery separately.
5. The two batteries should be kept together as a matched pair when using them with the Y Lead.
6. Inspect both batteries and connectors before connecting them.

Never connect a Small Battery to a Medium or Standard Assist PLUS Battery using the Y Lead.

Important – Air Travel With the Y Lead

The batteries must not be connected together during air travel.

Before going to the airport:

• Disconnect the Parallel Y Lead.
• Separate the batteries.
• Protect each battery individually against short circuit.
• Pack each battery in its own protective pouch or LiPo bag.
• Carry the batteries in your carry-on baggage.
• Follow the airline's approved battery quantity and packaging requirements.

The Y Lead itself should also be packed separately from the batteries so that the battery terminals cannot accidentally make contact.

Can I E-Foil With One Small Battery?

No.

The Small 4.2Ah Assist PLUS Battery is designed for Assist PLUS use only and is not intended to provide the continuous power required for e-foiling.

Do not use one Small Battery for Constant Power or e-foiling.

The same restriction applies when connecting two Small Batteries together with the Parallel Y Lead.

The Y Lead is designed to provide the equivalent capacity of the Medium battery for the intended Assist PLUS application, not to enable Constant Power operation.

What If I Need More Batteries?

If you need to travel with more batteries than your airline permits, consider arranging transport of the batteries to your destination before travelling.

Any shipment containing lithium-ion batteries must be arranged through a carrier that is authorised to transport dangerous goods and must comply with the applicable dangerous-goods shipping requirements.

Do not send lithium batteries through a standard freight service unless that carrier has confirmed that it is authorised and equipped to transport them.

Important Travel Disclaimer

Airline and dangerous-goods requirements can change and may vary between airlines, countries and routes.

The information in this article is intended as a general guide based on current 2026 IATA and Australian CASA guidance. It does not guarantee that an airline will accept your batteries.

It is your responsibility to contact your airline before travel, obtain any required approval and comply with the airline's specific requirements.

For the most current general guidance, refer to IATA – Safe Travel with Lithium Batteries and Australian CASA – Lithium Batteries.

If your airline's requirements differ from the information in this article, always follow the airline's requirements.