Batteries are genuinely one of the more confusing things to pack for a flight — not because they’re dangerous by default, but because the rules split completely based on battery chemistry. AA alkaline batteries and lithium-ion cells are treated as totally different items, and getting it wrong can mean a confiscated power bank or a delayed bag. This guide covers every 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.