Batteries are among the most regulated items in aviation — not because they’re dangerous by default, but because certain types of batteries can cause fires in the cargo hold. Different battery chemistries have completely different rules. This guide covers every battery type: AA, AAA, lithium-ion, lithium metal, rechargeable, and button cells.
TSA Rules Summary
| Battery Type | Carry-On | Checked Bag |
|---|---|---|
| AA alkaline batteries | ✅ Allowed | ✅ Allowed |
| AAA alkaline batteries | ✅ Allowed | ✅ Allowed |
| C and D batteries | ✅ Allowed | ✅ Allowed |
| 9V alkaline batteries | ✅ Allowed | ✅ Allowed |
| Lithium AA/AAA (non-rechargeable) | ✅ Allowed | ✅ Allowed |
| Lithium-ion (rechargeable, under 100Wh) | ✅ Allowed | ⚠️ In device only |
| Lithium-ion (spare, under 100Wh) | ✅ Carry-on only | ❌ Prohibited |
| Lithium-ion (100–160Wh) | ✅ With airline approval | ❌ Prohibited |
| Button/coin cell batteries | ✅ Allowed | ✅ Allowed |
| CR2032 batteries | ✅ Allowed | ✅ Allowed |
| Car batteries (lead-acid) | ❌ Prohibited | ❌ Prohibited |
Official Regulations
Alkaline Batteries (AA, AAA, C, D, 9V) — Easiest Case
Standard alkaline batteries — the kind you buy for remotes, flashlights, and toys — are allowed in both carry-on and checked baggage with no quantity restrictions. AA batteries, AAA batteries, C batteries, D batteries, and 9V batteries are all fully permitted anywhere in your luggage.
[!IMPORTANT] Even though alkaline batteries are unrestricted, loose batteries in checked luggage can short-circuit if they contact metal objects. For safety, keep batteries in their original packaging or in a battery case, and tape the terminals of any batteries not in their original packaging.
Lithium Batteries — The Complex Case
Lithium batteries are where aviation rules get specific. There are two types:
Lithium Metal (Non-Rechargeable)
- Common in: certain AA/AAA batteries, CR123A, CR2032 button cells
- Carry-on: ✅ Allowed
- Checked bags: Allowed if installed in a device; spare lithium metal batteries limited to 2g lithium content per battery
Lithium-Ion (Rechargeable)
- Common in: smartphones, laptops, power banks, cameras
- The regulations are based on watt-hour (Wh) capacity:
| Lithium-Ion Wh Rating | Carry-On | Checked Bag |
|---|---|---|
| Under 100Wh | ✅ Allowed | ✅ In device only (spares in carry-on) |
| 100–160Wh | ✅ With airline approval | ❌ Prohibited |
| Over 160Wh | ❌ Prohibited | ❌ Prohibited |
Key rule: Spare lithium-ion batteries (not installed in a device) are never allowed in checked bags. They must always be in your carry-on, in their original packaging or with terminals protected.
Button / Coin Cell Batteries (CR2032, CR2025, etc.)
Button cell batteries (watch batteries, hearing aid batteries, key fob batteries, CR2032) follow alkaline battery rules:
- Carry-on: ✅ Allowed
- Checked bags: ✅ Allowed
- No quantity restrictions for personal use
Rechargeable AA/AAA Batteries (NiMH)
Nickel-metal hydride (NiMH) rechargeable batteries like Eneloop AA/AAA follow the same rules as standard alkaline batteries — permitted in carry-on and checked bags without restriction.
Protecting Batteries at Security and in Luggage
TSA recommends protecting battery terminals to prevent accidental short circuits:
- Keep in original retail packaging — Most packaging isolates the battery terminals
- Use battery cases — Plastic battery storage cases are inexpensive and available everywhere
- Tape the terminals — Apply a strip of electrical tape or masking tape over the positive (+) terminal of loose batteries
- Separate from metal objects — Don’t store loose batteries with keys, coins, or other metal items
Airline-Specific Battery Policies
Most airlines follow FAA regulations, but some have additional rules:
| Airline | AA/AAA | Lithium Spare (under 100Wh) | Lithium in Device (checked) |
|---|---|---|---|
| Delta | ✅ Either bag | ✅ Carry-on only | ✅ Checked OK |
| United | ✅ Either bag | ✅ Carry-on only | ✅ Checked OK |
| American | ✅ Either bag | ✅ Carry-on only | ✅ Checked OK |
| Ryanair | ✅ Either bag | ✅ Carry-on only | ✅ Checked OK |
| Emirates | ✅ Either bag | ✅ Carry-on only | ✅ Checked OK |
Essential Traveler Tips
- Spare lithium batteries always in carry-on — Never put loose rechargeable batteries in a checked bag. This is the single most important battery rule.
- Protect terminals on loose batteries — A short-circuited lithium battery can cause a fire. Keep batteries in cases or original packaging.
- Bring enough for the trip — Many international destinations have limited stocks of specific battery types (like CR123A for camera equipment). Bring spares in your carry-on.
- Know your device’s Wh — If you’re traveling with large battery packs, check the Wh rating before you fly. Over 100Wh requires airline approval.
Common Mistakes to Avoid
- Mistake 1: Putting spare lithium-ion batteries in checked luggage. This is prohibited. All spare rechargeable batteries must travel in carry-on bags.
- Mistake 2: Leaving batteries loose in a bag with metal items. Metal objects can bridge battery terminals and cause short circuits. Keep batteries protected.
- Mistake 3: Traveling with car/motorcycle batteries. Lead-acid vehicle batteries are prohibited on passenger aircraft — carry-on and checked.
Frequently Asked Questions
Q: Can you bring batteries on a plane? A: AA, AAA, and alkaline batteries are allowed in carry-on and checked bags. Lithium-ion spare batteries must be in carry-on only.
Q: Are AA batteries allowed on planes? A: Yes. AA alkaline batteries are permitted in carry-on and checked baggage with no restrictions.
Q: Are AAA batteries allowed on planes? A: Yes. AAA alkaline batteries are fully permitted in both carry-on and checked luggage.
Q: Can you bring triple A batteries on a plane? A: Yes. Triple-A (AAA) batteries are allowed in carry-on and checked bags without restriction.
Q: Can CR2032 batteries go in checked luggage? A: Yes. CR2032 and other button cell batteries are allowed in both carry-on and checked baggage.
Q: Are lithium batteries allowed on planes? A: Lithium batteries installed in devices are allowed in checked bags. Spare lithium batteries must travel in carry-on only, in original packaging or with protected terminals.
Q: Can you bring rechargeable batteries on a plane? A: Yes. NiMH rechargeable AA/AAA are unrestricted. Lithium-ion rechargeable spares must be in carry-on.
Conclusion
Alkaline batteries (AA, AAA, C, D, 9V) are the simplest case — they go anywhere in any quantity. The critical rule is for lithium-ion batteries: spare rechargeable batteries must always be in carry-on, never in checked bags. Protect all loose battery terminals to prevent short circuits, and you’ll have no issues at any airport security checkpoint worldwide.