Every fall someone walks into the shop with a drone case, a 6S basher pack and a plane ticket, and asks the same question: "Can I take these on the flight?" Usually yes. But the rules are about watt-hours, not milliamp-hours, and they treat a battery in your drone very differently from a spare in your backpack. Get it wrong and the pack stays at the checkpoint, or worse, rides in the cargo hold where nobody can see it if it misbehaves.
This guide puts the FAA, TSA and U.S. Postal Service rules in hobby terms, as they read in October 2026. You'll work out your pack's watt-hours, see which RC and drone batteries need airline approval, learn how to pack spares, and find out why a LiPo you mail has to go by ground. Airlines can be stricter than the federal rules, so check with yours before you fly.
The Short Answer
Spare LiPo batteries must go in your carry-on, never your checked bag, with the terminals protected. Packs up to 100 Wh are allowed; 101 to 160 Wh need airline approval and you can bring two; over 160 Wh can't fly.
- Watt-hours = volts × amp-hours. A 4S 5000mAh pack is about 74 Wh; a 6S 5000mAh pack is about 111 Wh.
- A drone or RC car with its battery installed can be checked only if it is fully off and protected from switching on; the FAA says carry-on is better.
- Tape or cap the connectors and put each pack in a case or a snug pouch.
- Mailing a loose LiPo through USPS is surface (ground) only, 100 Wh or less per battery, with special marking.
1. Know Your Pack in Watt-Hours
Airline rules don't care about mAh, cell count or C rating. They care about energy, measured in watt-hours (Wh). The FAA's passenger battery guidance gives the formula: multiply the volts by the amp-hours. For a pack rated in mAh, divide by 1,000 first to get Ah.
The math on a real pack
A 3S LiPo is 11.1 V nominal. A 3S 2200mAh airplane pack is 11.1 × 2.2 = 24.4 Wh. A 6S 5000mAh basher pack is 22.2 × 5.0 = 111 Wh. Use the nominal voltage printed on the label, not the 4.2 V-per-cell full-charge voltage. Many packs, and almost all drone batteries, print the Wh rating right on the label; if yours does, use that number. Airport staff will look for it, so a pack with a clear Wh marking is easier to get through.
Common RC and drone packs, sorted by the FAA limits
| Pack | Math | Watt-hours | Carry-on as a spare? |
|---|---|---|---|
| 2S 5200mAh (7.4 V) car pack | 7.4 × 5.2 | 38.5 Wh | Yes |
| 3S 2200mAh (11.1 V) plane pack | 11.1 × 2.2 | 24.4 Wh | Yes |
| 4S 5000mAh (14.8 V) basher pack | 14.8 × 5.0 | 74.0 Wh | Yes |
| 6S 5000mAh (22.2 V) | 22.2 × 5.0 | 111.0 Wh | Only with airline approval, 2 max |
| 6S 7200mAh (22.2 V) | 22.2 × 7.2 | 159.8 Wh | Only with airline approval, 2 max |
| 6S 8000mAh (22.2 V) | 22.2 × 8.0 | 177.6 Wh | No, over 160 Wh |
Most camera-drone batteries and almost every car, plane and FPV pack land under 100 Wh. It's the big 6S packs for 1/5 scale trucks, large helis and heavy-lift drones that hit the approval range or go over it.
Where the limits come from
The FAA's PackSafe lithium battery page limits lithium ion batteries to 100 Wh each, and allows up to two spare larger batteries of 101 to 160 Wh with airline approval. Spares must be for your own use. The FAA's passenger page says batteries over 160 Wh are not allowed. LiPo packs are lithium ion for these rules. Airlines can set lower limits or cap how many spares you bring, so read your carrier's battery page before you pack.
2. How to Pack Batteries and Gear for a Flight
The rule that trips up most hobbyists is where the battery goes. A spare pack and a pack installed in a device follow different rules, and checked bags are off-limits for spares no matter how small they are.
Spares ride in the cabin, every time
The FAA says spare lithium batteries, including power banks, go in carry-on baggage only. TSA's What Can I Bring entry says the same: carry-on yes, checked bags no. If the gate agent makes you check your roller bag at the jet bridge, the FAA says to take every spare battery out of it and keep them with you. Pack your LiPos in a small bag you'll never hand over.
Protect the terminals
A loose pack with a bare connector can short against keys, coins or another pack. The FAA lists the accepted fixes: leave the battery in its retail packaging, tape over the terminals, use a battery case, or put it snugly in a plastic bag or protective pouch. For RC packs, we cap or tape the main lead and the balance plug, then put each pack in its own pouch or a LiPo safety bag so the packs can't rub. Check per-cell voltage before you leave. A pack that is puffed, dented or has a cell far off the others stays home. The FAA bars damaged or recalled batteries from aircraft.
Drones and RC cars with the battery installed
The FAA's guidance for devices containing batteries says they should go in carry-on. If one has to be checked, it must be completely powered off and protected so it can't switch on or get damaged. For most hobbyists the easy answer is to carry the drone or truck on and pull the battery so it travels as a protected spare. The FAA's drone dangerous goods brochure also reminds owners that cameras, speakers and some parachute systems can contain batteries or other dangerous goods. Check every accessory, not just the flight packs.
A pre-flight packing checklist
- Add up the Wh of every pack. Anything from 101 to 160 Wh: get airline approval in writing and bring no more than two.
- Leave anything over 160 Wh at home, or ship it by ground (see below).
- Check each pack's cell voltages and leave damaged or puffy packs behind.
- Run packs down to a storage charge. It isn't a federal rule, but it's how we store LiPos anyway, and a pack that isn't full has less energy to release if something goes wrong.
- Cap or tape every connector, bag each pack, and put them all in your personal item.
- Pack the charger in your carry-on too, and plan to charge at your destination on a non-flammable surface in a LiPo bag.
3. Shipping a LiPo: Why It Goes by Ground
Sometimes the better plan is to ship the packs ahead, or send a 6S pack home that you couldn't carry on. Mailing lithium batteries has its own rulebook, and the main point is simple: loose LiPos don't fly in the mail.
USPS limits for lithium ion batteries
USPS Publication 52, section 349 limits mailable lithium ion cells to 20 Wh and batteries to 100 Wh, and each battery has to be marked with its Wh rating. Batteries mailed by themselves, not packed with or installed in equipment, must travel by surface transportation only (the one exception is mail within Alaska), with the mailpiece at 5 pounds or less. That rules out mailing most big 6S packs through the Postal Service at all.
Batteries packed with or inside equipment
A battery installed in, or packed with, the drone or radio it powers can go by air or surface under Pub 52, limited to two batteries (or eight cells) per mailpiece at those same Wh limits, with the lithium battery mark when required. The equipment must be protected from switching on, and the batteries from short circuit and damage.
Packaging and marking basics
Pub 52 calls for rigid outer packaging, each battery cushioned so it can't move, complete delivery and return addresses, and the DOT lithium battery mark. Loose batteries also need the "Surface Mail Only" wording. Damaged, defective or recalled batteries can't be mailed. UPS, FedEx and other carriers write their own rules, so ask them before you ship with anyone but USPS.
Conclusion
Traveling with RC and drone batteries is simple once you think in watt-hours. Packs up to 100 Wh go in your carry-on with the terminals protected. Packs of 101 to 160 Wh need your airline's approval, two at most. Anything bigger stays on the ground, and if you mail a loose pack through USPS, it goes by surface and must be 100 Wh or less. Pull batteries out of your gear when you can, check every pack before you leave, and keep them all with you in the cabin.
Not sure what your pack is rated, or whether a cell is healthy enough to travel? Bring it by our Cumming showroom and we'll check it with you, or contact the shop. We stock LiPo safety bags and battery checkers for the trip.
Gear Mentioned in This Guide
Racers Edge LiPo Battery Charging Safety Bag (up to 6S) (RCE2100)
A snug, padded home for spare packs in your carry-on, and the right place to charge them at the hotel.
Shop now
Spektrum Smart Battery Checker & Servo Tester XBC200 (SPMXBC200)
Check per-cell voltage before you pack, and spot a weak or damaged cell before it gets on a plane.
Shop now
Racers Edge LiPo Battery Charging Safety Sack (300mmx220mm) (RCE2103)
Larger sack for long 6S packs or a pair of drone batteries.
Shop nowFrequently Asked Questions
Can I bring LiPo batteries on a plane?
Yes, as spares in your carry-on with the terminals protected. The FAA allows lithium ion batteries up to 100 Wh each, and up to two spares of 101 to 160 Wh with airline approval. Spare LiPos are never allowed in checked bags.
How do I work out the watt-hours of my LiPo?
Multiply the nominal voltage by the capacity in amp-hours. Divide mAh by 1,000 to get Ah. A 4S 5000mAh pack is 14.8 × 5.0 = 74 Wh. If the label prints a Wh rating, use that.
Can I check my drone if the battery is installed?
The FAA says devices with lithium batteries should be carried on. A checked device must be completely powered off and protected from switching on or being damaged. Most pilots carry the drone on, or remove the battery and carry it as a protected spare.
Is a 6S 5000mAh battery allowed on a plane?
At 22.2 V, a 6S 5000mAh pack is about 111 Wh, so it needs airline approval, and you can carry no more than two packs between 101 and 160 Wh. Ask your airline before you go; some set stricter limits.
Can I mail a LiPo battery through USPS?
Yes, by surface (ground) transportation only if it's mailed by itself, at 100 Wh or less, marked with its Wh rating, in a mailpiece of 5 pounds or less with the DOT lithium battery mark. Batteries over 100 Wh can't be mailed under these rules.
Do I have to discharge my LiPo before flying?
The FAA rules we cite don't set a charge level for passengers' spare batteries. We still recommend a storage charge for travel, since that's the safest way to store a LiPo anyway.
