Yes, spare phone batteries and power banks must ride in carry-on; keep under 100 Wh, cover terminals, and never place spares in checked bags.
Air travel rules around batteries confuse plenty of smart travelers. The good news: the limits are clear once you split things into two groups — batteries inside a device and spare batteries. Phones, tablets, and laptops with a battery installed can fly. Spare batteries, including power banks and loose phone cells, stay in your hand baggage only.
What Counts As An Extra Phone Battery
An “extra phone battery” means any spare cell that is not installed in a device. That includes a removable phone battery, a clip-on charging case, and every power bank. Aviation rules treat power banks as spare lithium batteries, so they follow the same carry-on only rule and the same watt-hour limits.
Bringing An Extra Phone Battery On A Plane: Quick Rules
Here’s the fast way to check if your spare will fly. Match your battery type and size to the row below, then pack it the right way.
| Battery Or Item | Where It Goes | Limits & Notes |
|---|---|---|
| Lithium-ion spare (power bank, phone cell) | Carry-on: Yes; Checked: No | ≤100 Wh allowed. 101–160 Wh needs airline approval (max 2 spares). Terminals covered. |
| Lithium-ion installed in phone/tablet/laptop | Carry-on: Yes; Checked: Yes* | *If checked, device fully off and protected from switching on. Carry-on is safer. |
| Lithium metal spare (CR123, camera cell) | Carry-on: Yes; Checked: No | Up to 2 g lithium content per battery. Terminals covered. |
| Dry cells (alkaline, NiMH, NiCd—AA/AAA/C/D) | Carry-on: Yes; Checked: Yes | Pack to prevent short-circuit. Tape exposed terminals for spares. |
| Power bank (counts as spare lithium-ion) | Carry-on: Yes; Checked: No | Same limits as lithium-ion spares. Keep in seat bag, not the hold. |
| Damaged, swollen, or recalled batteries | Carry-on: No; Checked: No | Do not fly with unsafe cells. Replace before travel. |
These rules line up with aviation safety guidance. The TSA and the FAA PackSafe pages give the same carry-on only rule for spare lithium batteries and the 100 Wh baseline with a 101–160 Wh window when your airline says yes.
Carry-On Packing Steps That Pass Screening
Protect The Terminals
Cover each set of exposed contacts so nothing metal can touch them. Use the original caps, a small battery box, or wrap the ends with non-conductive tape. This stops short-circuits in a crowded bag.
Pack Each Battery Separately
Loose cells should not touch each other at all. Slip each spare into a small zip-top bag or a rigid case. That keeps coins and chargers from bridging the contacts.
Pick A Smart Spot
Place power banks and spare phone batteries where you can reach them fast. If a screener wants a closer look, you can present them without digging through clothing or food.
Label Matters
Most batteries print the rating in watt-hours. If your unit only shows mAh and volts, write the watt-hours on painter’s tape and stick it on the pack after you do the math below. A clear label speeds up any question at the checkpoint.
Capacity Limits: mAh Vs Wh Made Simple
Airlines and regulators use watt-hours to size a battery. You can convert milliamp-hours with one line of math:
Quick Math You Can Copy
Wh = (mAh ÷ 1000) × Volts
Most phone power banks use 3.6–3.7 V cells. Here are common examples:
- 10,000 mAh at 3.7 V → 37 Wh — fine in carry-on.
- 20,000 mAh at 3.7 V → 74 Wh — fine in carry-on.
- 26,800 mAh at 3.7 V → ~99 Wh — the usual “max” that stays under 100 Wh.
- 30,000 mAh at 3.7 V → ~111 Wh — you’ll need airline approval, and only two spares allowed.
Anything over 160 Wh does not fly with you as a spare. That size belongs to large gear and needs freight handling, not a seat bag.
Edge Cases That Trip People Up
Spare Battery In Checked Bags
This is the big no. Spares — including every power bank — must never go in checked luggage. If a gate agent tags your roller for planeside checking, remove the spare and carry it into the cabin with you.
Installed Battery In Checked Bags
Most airlines let you check a device with the battery installed, but they want it powered off, with switches protected, and packed to avoid pressure on the device. A phone or laptop rides safer in your cabin bag where crew can respond fast if anything overheats.
Clip-On Charging Cases
Those phone cases with built-in cells count as spares when they are not on the phone. Pack them the same way you pack a power bank: carry-on only and protected.
Button Cells And Camera Packs
Button cells in watches and car fobs are fine in any bag. Camera packs marked as lithium metal are spares, so they ride in carry-on and cap at 2 g lithium content per battery.
No-Label Power Banks
If the pack shows no mAh or Wh, you may be asked to leave it behind. Pick gear with a printed rating, or bring a small receipt card that lists the capacity.
Airline Rules That Can Differ
Safety baselines come from global rules, yet individual carriers can set tighter caps on quantity or usage in flight. Some carriers cap the number of spares you can carry or ask you not to use a power bank while seated. When your spare sits in the 101–160 Wh range, you need approval before you fly, and you’re limited to two of those larger spares. For smooth boarding, read your airline’s battery page after you check the TSA and FAA pages above.
Real-World Packing Wins
One Phone, One Bank
Bring one mid-size pack around 10,000–20,000 mAh. It clears every airline with room to spare and covers a full travel day without hunting for outlets.
Traveling With Multiple Gadgets
Two smaller banks beat one giant brick. You’ll keep each unit well under 100 Wh, spread the load between daypack and purse, and cut the weight in your hand.
Long Layovers
Charge all banks before security. Many airports limit outlets past the checkpoint. A full charge at home means fewer cables to juggle while you wait to board.
Checkpoint Situations And Fixes
Agent Says “That Must Be Checked”
Spare lithium batteries cannot go in the hold. If someone asks you to check a bag that contains a power bank, take the battery out and carry it on. Showing the TSA battery page on your phone can help clear up the confusion fast.
Swollen Or Hot Battery
Do not fly with it. Replace the unit and recycle the old one at a drop point. If you notice heat or smoke on board, call a crew member right away.
Forgot The Tape
No tape? Slide each spare into a small zip bag so the contacts can’t touch metal. Many checkpoints also offer a roll of tape if you ask.
mAh To Wh Cheat Sheet
Use this chart to tag your gear before you pack. Values assume 3.7 V cells.
| Label On Pack | Math | Result In Wh |
|---|---|---|
| 5,000 mAh | 5,000 ÷ 1000 × 3.7 | 18.5 Wh |
| 10,000 mAh | 10,000 ÷ 1000 × 3.7 | 37 Wh |
| 20,000 mAh | 20,000 ÷ 1000 × 3.7 | 74 Wh |
| 26,800 mAh | 26,800 ÷ 1000 × 3.7 | 99.2 Wh |
| 30,000 mAh | 30,000 ÷ 1000 × 3.7 | 111 Wh* |
*Ask your airline for approval if you plan to carry a spare in this range, and remember the two-spare limit for 101–160 Wh.
Quick Pre-Flight Checklist
- Spare batteries and power banks packed in carry-on only.
- Each spare protected from short-circuit — caps, tape, or a case.
- Capacity labeled in Wh, or mAh with the conversion written on the pack.
- No damaged or swollen cells in any bag.
- If a roller gets gate-checked, pull the spares before handing it over.
Why Spares Stay In The Cabin
Lithium cells can overheat if crushed or shorted. In the cabin, crew can see smoke, cool the pack, and contain it. In the hold, that quick response is tougher, so spare batteries stay with you.
International Connections And Transit Points
Rules look similar worldwide, yet screening can feel stricter in some airports. Keep spares in a small pouch you can show on request, with the watt-hour rating visible. If a pack is 101–160 Wh, carry your airline’s approval note with it.
Small Gear People Forget
Magnetic phone packs count as power banks. Coin-cell trackers ride anywhere. Camera cells marked as lithium metal ride in carry-on only, with contacts covered.
Carry-On Strategy When Space Is Tight
Gate-check coming? Move your battery pouch into your personal item before you hand over a roller. That one habit prevents last-minute scrambles at the door. Keep a spare cable with the pouch so you can charge without unpacking. Label each bank with its Wh to speed any questions quickly.
Final Checks That Save Time
Keep your spare phone battery and power bank easy to reach. Make sure the rating is visible, the ends are covered, and the pack sits under 100 Wh unless your airline approved a larger one. That simple setup keeps your trip smooth on any route.