Michael Turner
Immediate instruction: Store spare lithium-ion battery packs inside cabin or carry-on baggage only; do not place spare cells or loose external battery units in checked baggage.
Regulatory limits follow IATA/ICAO guidance: up to 100 Wh per cell or pack is generally permitted in cabin without airline approval; between 100 Wh and 160 Wh requires airline approval and is normally limited to two spare units per passenger; items exceeding 160 Wh are restricted to specialized cargo shipments with prior carrier arrangements.
Capacity calculation: Wh = (mAh / 1000) × V. When only mAh is printed, assume nominal cell voltage 3.7 V unless the manufacturer specifies otherwise. Examples: 10,000 mAh × 3.7 V = 37 Wh; 20,000 mAh = 74 Wh; 27,000 mAh ≈ 100 Wh; 50,000 mAh ≈ 185 Wh (likely prohibited).
Safety steps: protect terminals against short circuits (tape terminals or keep each unit in separate plastic bags), keep devices turned off during transit, carry installed batteries inside the device in cabin baggage, and limit the number of spare packs. Declare any units that exceed 100 Wh at check-in when airline policy requires notification.
Practical checklist: verify the Wh rating on the label, calculate Wh when only mAh is shown, check the carrier’s battery policy before departure, secure terminals, and obtain written airline approval for units between 100–160 Wh.
Battery capacity limits: up to 100 Wh; 100–160 Wh with airline approval; over 160 Wh prohibited
Keep battery units at or below 100 Wh for unrestricted carriage in cabin baggage; each unit must have terminals insulated (tape or original casing), be individually protected against short circuit, and comply with the carrier’s per-passenger item count.
100–160 Wh – airline approval required
Cells between 100 Wh and 160 Wh require written or verbal approval from the carrier before boarding. Typical carrier practice: a maximum of two spare units between 100–160 Wh per passenger, and installed batteries in devices may not count toward the spare limit but still need authorization. Calculate watt-hours when only mAh and voltage are shown: Wh = (mAh ÷ 1000) × V (example: 10,000 mAh at 3.7 V = 37 Wh). Declare such units at check-in if requested and keep documentation of rated Wh accessible.
Over 160 Wh – forbidden in passenger transport
Items exceeding 160 Wh are prohibited from both cabin and hold on passenger aircraft; shipment as cargo demands dangerous-goods paperwork, special packaging, and carrier acceptance that most airlines refuse for consumer cells. For disposal, return-to-retailer or specialised hazardous-goods shippers are recommended. Reference: how to keep dog from biting fence
How to convert mAh to Wh (formula and example) to confirm a portable battery’s rating
Use Wh = (mAh × V) / 1000; when only mAh is printed, assume nominal cell voltage 3.7 V unless the manufacturer specifies a different internal voltage or provides Wh directly.
Procedure: take the mAh value, determine the appropriate voltage (internal nominal ≈ 3.7 V or the specified output voltage if mAh is declared at USB output), multiply mAh by V, then divide by 1000 to obtain Wh. Round to one decimal place for documentation.
Worked example 1 (typical label with no voltage): 20,000 mAh → (20,000 × 3.7) / 1000 = 74.0 Wh. Worked example 2 (label specifies output voltage): 20,000 mAh at 5 V → (20,000 × 5) / 1000 = 100.0 Wh. If the manufacturer prints Wh on the unit or spec sheet, use that printed value for formal checks.
Conversions from ampere-hours: use Wh = Ah × V (example: 2.0 Ah × 3.7 V = 7.4 Wh). If calculated Wh sits close to regulatory thresholds, obtain the spec sheet or manufacturer confirmation and keep the Wh figure available for carrier verification.
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Packing rules for carry-on: terminal protection, labeling, and accessible placement
Terminal protection
Insulate all battery pack terminals with non-conductive covers before stowing. Valid methods: factory terminal caps, heat-shrink tubing, or 2–3 layers of electrical or Kapton tape covering the entire conductive surface. Place each unit inside individual zip-lock or anti-static pouch to prevent contact with metal objects (keys, coins, zippers).
Pad units with foam, cardboard dividers, or original retail trays so no terminal can press against another device. Ensure external cables cannot create a circuit (store cables separately or coil and secure with a tie). Switch devices off and lock any mechanical switches to prevent accidental activation.
Labeling, documentation, and accessible placement
Affix a legible label showing rated watt‑hours (Wh), chemistry (e.g., Li‑ion), model, and manufacturer; use a waterproof printed sticker or permanent marker. If written airline approval or special documentation exists, attach it adjacent to the unit and keep a duplicate in the bag pocket for inspection.
Store all units in cabin carry-on where inspection and crew access are possible: an outer pocket of a personal item, a clearly marked compartment of a carry‑on, or the original box placed on top of other items (not buried). Avoid placing units in checked baggage. Keep a clear, unobstructed route to the item so security or crew can remove and test without emptying the entire bag.
How to verify carrier and country-specific restrictions before you fly
Check the operating carrier’s Dangerous Goods / Conditions of Carriage pages and obtain written approval for any portable battery packs that exceed airline thresholds at least 72 hours before departure.
- Identify relevant carriers:
- Confirm operating carrier(s) (not only the marketing airline) from the booking; codeshares often follow the operating carrier’s rules.
- If the itinerary includes a regional partner or separate ticket for a connecting sector, verify each operator’s policy.
- Where to look online:
- Airline site: search site sections named “Dangerous Goods”, “Baggage Policy”, “Conditions of Carriage” or “What not to bring”.
- National aviation authorities: FAA (faa.gov), EASA (easa.europa.eu), UK CAA (caa.co.uk), Transport Canada (tc.gc.ca), CASA (casa.gov.au), CAAC (caac.gov.cn).
- IATA guidance pages (iata.org) for industry-standard wording and terminology used by carriers.
- Exact search phrases to use on airline sites:
- “[Airline name] lithium battery policy”
- “[Airline name] dangerous goods portable battery”
- “[Airline name] approval for batteries over” (insert known Wh value)
- When online policy is unclear:
- Contact airline customer service by phone and by email; request written confirmation (screenshot or PDF) citing the booking reference.
- Send a single clear message containing: flight number(s), booking reference, item model, battery rating in Wh, quantity, whether installed or spare, and planned connections.
- Retain timestamps and agent name or ticket number for future presentation at check-in/security.
- Transit and destination rules:
- Check customs and civil aviation pages of transit/destination states for import or transit prohibitions; policies can differ from the departing state.
- If entering a state with strict import controls, obtain airline confirmation that transit through that state is permitted with the declared items.
- Timing and quantity limits:
- Request approvals at least 72 hours before departure; allow up to 7 days for complex multi-carrier itineraries.
- Ask the carrier to confirm any per-passenger or per-flight quantity limits and whether multiple items require individual approvals.
- Documentation to carry:
- Printed or offline-copied airline approval, manufacturer label showing Wh/voltage/mAh, purchase invoice if available, and booking confirmation.
- Have screenshots of relevant airline and authority policy pages with capture date visible.
- At the airport:
- Present written approvals at check-in and security; if an agent disputes the item, request escalation and copy of the policy cited by staff.
- If denied carriage, keep written denial for claims or rebooking; ask for options (e.g., return shipment, local disposal) and document instructions.
- If carrying multiple carriers on one ticket:
- Require confirmation from the operating carrier for each flight segment; a single airline’s approval may not cover partner-operated legs.
Security screening: what officers may ask, when devices are confiscated, and declaration requirements
Present portable battery packs separately in the security tray; officers commonly request visible capacity labels, manufacturer specifications, written airline approval for oversized units, and verification that cells show no physical damage or swelling.
Typical screening questions target device status and documentation: device type (installed versus spare), declared capacity and label legibility, quantity of spare cells, terminal protection method, whether the unit powers on, signs of modification or aftermarket cells, and possession of any carrier approval or manufacturer data sheets.
Confiscation occurs for specific safety or compliance reasons: missing or unreadable capacity markings; physical damage, swelling, leakage, smoking, or overheating detected during screening; concealed cells inside checked bags when regulations mandate cabin carriage; multiple spare cells exceeding carrier-approved quantity without documentation; tampered seals, non-standard cell replacements, counterfeit or uncertified units; and refusal to present required documentation on request.
Declaration requirements: declare portable batteries at check-in and at security when requested or when a written carrier approval exists for larger-capacity items; present manufacturer data sheets, original packaging or label photographs, serial numbers, purchase receipts, and any airline approval email or printed form; keep all documentation immediately accessible for inspection.
Consequences for non-compliance include immediate confiscation and destruction of the item, denied boarding, flight delays, civil fines, reporting to civil aviation authorities, and potential involvement of law enforcement for intentional concealment or suspected hazardous shipment.
Practical recommendation: obtain written carrier approval before travel when uncertainty exists and carry printed documentation; expect permanent surrender of hazardous or non-compliant units for safety reasons.
FAQ:
Can I bring a 20,000 mAh power bank in my hand luggage on an international flight?
Most airlines allow power banks in hand luggage if their capacity is under 100 Wh. To check, convert mAh to watt-hours: Wh = (mAh / 1000) × V. Many power banks use 3.7 V, so a 20,000 mAh unit is about 74 Wh (20,000/1000 × 3.7 = 74 Wh) and would normally be permitted in carry-on. Make sure the device’s terminals are protected (taped or in original packaging) and verify any carrier-specific limits before travel.
Are power banks allowed in checked baggage?
No. International safety rules require most portable lithium batteries and power banks to travel in carry-on baggage only. Airlines and aviation authorities prohibit spare lithium batteries in checked luggage because of the fire risk. Installed batteries inside a powered-on device are usually acceptable in the cabin, but loose power banks should not be placed in checked bags.
How do I find the watt-hour rating if my power bank doesn’t show Wh?
Look for a printed Wh value on the product label or packaging first. If it’s missing, find the battery voltage (V) and capacity in mAh, then calculate Wh = (mAh / 1000) × V. If voltage is not listed, search the manufacturer’s website or product specifications online. If you cannot determine the Wh rating, the airline may refuse the item at check-in, so carry documentation or avoid bringing the unit.
Is there a limit on how many power banks I can carry in hand luggage?
Limits vary. For units under 100 Wh most carriers permit multiple power banks for personal use, but a few set a numeric cap (for example, a handful of airlines limit the count). For batteries rated between 100 Wh and 160 Wh, airlines often allow up to two spares per passenger but require airline approval before boarding. Any battery over 160 Wh is typically banned from both cabin and hold. Before flying, check the specific airline policy and declare larger batteries when asked.
Can I use a power bank to charge my phone during the flight?
Generally yes: using a personal power bank to charge devices in the cabin is allowed on most flights. Some carriers may ask passengers to stow external chargers during taxi, takeoff and landing, or may restrict in-seat charging depending on aircraft facilities. Avoid using damaged or hot power banks and keep cables tidy so the crew can inspect the device if requested. If you plan to bring high-capacity units (near 100 Wh), mention them at the gate if airline staff ask.
