Can I bring AA and AAA batteries on a plane?

Yes. Alkaline batteries such as AA, AAA, C, D, and 9V are allowed in both carry-on and checked luggage with no practical quantity limit. They pose minimal fire risk and face no special restrictions.

Can lithium-ion spare batteries go in checked luggage?

No. Spare lithium-ion batteries — not installed in a device — are prohibited in checked luggage on all commercial flights. They must travel in carry-on baggage only, where cabin crew can respond to any thermal event.

What is the 100 Wh limit for lithium batteries?

Most consumer lithium-ion batteries are under 100 Wh (watt-hours). Batteries between 100 Wh and 160 Wh require airline approval. Batteries over 160 Wh are banned entirely from passenger aircraft. A laptop battery is typically 50–99 Wh.

Do button cell batteries count as spare lithium batteries?

Most button cell batteries such as CR2032 are lithium primary cells. They are allowed in carry-on and typically in checked luggage too, as long as terminals are protected. Standard coin cells contain very little lithium and rarely trigger quantity limits.

Can I bring a battery bank on a plane?

Yes, but in carry-on only. Power banks are spare lithium-ion batteries and are banned from checked luggage. They must be in your carry-on, with terminals protected. Most power banks under 100 Wh are allowed without airline approval.

Can You Bring Batteries on a Plane?

Battery rules on aircraft exist for a good reason: lithium fires in cargo holds are difficult to extinguish and have caused serious incidents. The rules are based on chemistry, not arbitrariness, and once you understand the logic, the system is easy to navigate.

The fundamental split is between alkaline batteries (AA, AAA, C, D, 9V) and lithium batteries (lithium primary and lithium-ion). Each category has different rules, and within lithium batteries, whether the battery is installed in a device or spare makes all the difference.

Alkaline Batteries (AA, AAA, C, D, 9V)

Standard alkaline batteries are the safest category. They carry no meaningful fire risk and face essentially no restrictions under IATA (International Air Transport Association) regulations, which govern all commercial aviation.

Alkaline batteries in AA, AAA, C, D, and 9V formats are allowed in carry-on and checked luggage. There is no quantity limit enforced in practice for personal use. You could pack a bulk box of AA batteries in your checked bag without issue.

The one precaution worth taking: if batteries are loose (not in a device), cover the terminals with tape or keep them in their original packaging. This prevents accidental contact between terminals that could generate heat, though the risk with alkaline batteries is low.

Battery Rules by Type

Battery Type	Examples	Carry-On	Checked	Notes
Alkaline	AA, AAA, C, D, 9V	Yes	Yes	No quantity limit; protect terminals
Lithium primary (non-rechargeable)	CR123A, CR2032, AA lithium	Yes	Yes (with limits)	Max 2 spare batteries over 2g lithium content
Lithium-ion spare (rechargeable)	Power banks, laptop batteries	Yes only	No	Under 100 Wh free; 100–160 Wh needs approval
Lithium-ion installed in device	Phone, laptop, headphones, camera	Yes	Yes	Fine in any bag while installed in equipment
Nickel-metal hydride (NiMH)	Rechargeable AA, AAA	Yes	Yes	Treated like alkaline; protect terminals
Lead-acid (sealed)	Some camera flash systems	Restricted	Restricted	Rarely carried by travelers; check with airline

Lithium Primary Batteries (CR2032, CR123A, AA Lithium)

Lithium primary batteries — the non-rechargeable type — are slightly more tightly controlled than alkaline batteries because they contain metallic lithium rather than a lithium compound. However, standard small cells such as CR2032 button batteries contain so little lithium (often under 0.3g) that they are practically unrestricted.

The formal IATA rule states that lithium primary batteries with more than 2 grams of lithium content each require you to carry no more than 2 spare batteries. For context, a CR123A camera battery contains roughly 0.5g of lithium, and a standard AA lithium cell contains about 0.9g — both well under the threshold. CR2032 button cells contain roughly 0.12g. These are all permitted freely.

Lithium-Ion Spare Batteries: Carry-On Only

This is the most important rule for most travelers. Spare lithium-ion batteries — meaning rechargeable batteries not currently installed inside a device — are banned from checked luggage on all commercial flights worldwide. This includes:

Power banks and portable chargers
Spare laptop batteries
Spare camera batteries
Spare drone batteries
Spare e-bike batteries (most are also over the 160 Wh limit entirely)
Replacement smartphone batteries

The reasoning is straightforward: if a lithium battery catches fire in the cabin, crew can see it and respond. In the cargo hold, a battery fire can grow undetected until it causes catastrophic damage. The same rule applies on virtually every airline in every country.

Installed batteries — the battery inside your laptop, phone, camera, or tablet — may travel in checked bags inside the device because the device protects the battery and reduces the risk of short circuit.

The 100 Wh Rule

Lithium-ion batteries are rated in watt-hours (Wh), which indicates their energy capacity. The thresholds are:

Under 100 Wh: Allowed in carry-on, no airline approval needed. This covers virtually all consumer electronics: phones (typically 10–20 Wh), laptops (50–99 Wh), tablets (20–40 Wh), most power banks.
100 to 160 Wh: Allowed in carry-on with airline approval. Larger laptop batteries, some professional camera systems. You may carry a maximum of 2 spare batteries in this range.
Over 160 Wh: Prohibited on passenger aircraft entirely. Industrial batteries, large e-bike batteries, and most portable power stations fall into this category.

To find the Wh rating of a battery, look on the battery label. If the label shows voltage (V) and milliamp-hours (mAh), multiply them and divide by 1000: Wh = (V × mAh) / 1000. A 20,000 mAh power bank at 3.7V works out to about 74 Wh — comfortably under the limit.

Protecting Battery Terminals

The TSA and IATA both require that spare battery terminals be protected. Keep batteries in their original retail packaging, use individual battery cases, or cover terminals with non-conductive electrical tape. Store batteries separately from metal objects like keys and coins. Loose batteries rattling around with metal items are a short-circuit risk — terminal protection is a quick, cheap precaution.

Installed Batteries in Devices

Any battery physically installed inside its designed device — the battery in your phone, laptop, camera, or wireless headphones — is permitted in both carry-on and checked luggage without special restriction, subject to the Wh limits above. The device itself provides mechanical protection. There is no need to remove installed batteries for travel.

The core principle is simple: spare lithium-ion batteries belong in your carry-on bag, alkaline batteries can go anywhere, and large lithium batteries over 100 Wh need a check with the airline before you fly.