Can You Send Batteries in the Mail? USPS Rules and Limits

Yes, you can send most batteries in the mail, but the rules turn on what chemistry the battery is, how much energy it stores, and whether it’s shipped loose or inside the device it powers. The U.S. Department of Transportation classifies batteries as hazardous materials because they can short-circuit, overheat, or ignite in transit.¹ Ordinary alkaline cells are the easiest to send. Lithium batteries face the tightest limits. Damaged, defective, or recalled batteries can’t go through USPS at all.

Which Batteries USPS Will Accept

Not every chemistry is treated the same. The general pattern: the more energy a battery holds and the more reactive its chemistry, the more paperwork and packaging you owe.

Alkaline and nickel-metal-hydride (NiMH) household batteries such as AA, AAA, C, D, and rechargeable NiMH cells are not regulated as hazardous materials. You can mail them with ordinary packaging as long as terminals are protected, and no special labels are required.²
Lithium-ion rechargeable batteries, the kind in phones, laptops, and power banks, are mailable within watt-hour limits and face air-transport restrictions when shipped loose.
Lithium metal non-rechargeable batteries, found in watches, cameras, and some medical devices, are mailable within lithium-content limits, and are also barred from air transport when shipped without a device.
Lead-acid car batteries containing liquid electrolyte are prohibited. Sealed nonspillable lead-acid batteries can be mailed if the outer packaging is plainly marked “NONSPILLABLE BATTERY.”³
Damaged, defective, or recalled batteries of any chemistry are prohibited from USPS entirely, by both surface and air.⁴

Lithium Battery Size Limits

Because lithium batteries hold so much energy for their size, USPS caps how large they can be regardless of whether they’re shipped inside a device or on their own.

For lithium-ion rechargeable batteries, no single cell may exceed 20 watt-hours and no complete battery may exceed 100 watt-hours.⁵ A typical smartphone battery runs about 10 to 15 Wh and a laptop battery is usually 50 to 70 Wh, so ordinary consumer electronics fit inside the ceiling. Batteries above 100 Wh, like those in e-bikes and large portable power stations, can’t go through USPS.

For lithium metal non-rechargeable batteries, the ceiling is 0.3 grams of lithium per cell and 2 grams per battery.⁵ A standard CR2032 coin cell contains roughly 0.1 grams, well inside the limit.

Quantity Per Package

For lithium batteries installed in or packed with a device, each mailpiece may contain no more than 8 cells or 2 batteries.⁵ For loose batteries shipped without any device, the entire mailpiece can’t exceed 5 pounds. Very small consumer lithium batteries such as coin cells have no per-package quantity cap when shipped inside or with equipment.

Ground Only or Air Allowed

This is where senders stumble most often. Whether a lithium battery can fly comes down to one question: is it inside a device?

Installed in equipment (battery in a phone, laptop, or other device and properly secured): mailable by both air and ground.⁵
Packed with equipment (battery in the same box as the device but not installed): mailable by both air and ground.
Without equipment (loose batteries in original sealed packaging): surface transportation only. Prohibited from air.

The practical result: a spare laptop battery mailed by itself has to go by USPS Retail Ground or Parcel Select Ground. Priority Mail and Priority Mail Express run on air networks, so loose lithium batteries can’t ride those services. The same phone with the battery still installed can go Priority Mail without a problem. Used, damaged, or defective devices containing lithium batteries are also limited to ground service domestically.⁶

Ground-only packages must carry the text “Surface Mail Only” alongside the statement that the contents are forbidden on passenger aircraft, as required by Packaging Instruction 9D.⁵

How to Package Batteries

Even a legal shipment becomes a fire hazard if it’s packed carelessly. The whole point of the packaging rules is to prevent short circuits, since a terminal touching metal or another terminal can heat up fast.

Cover each terminal with non-conductive tape, or seal each battery in its own plastic bag or protective sleeve. This is the single most important step for loose cells.
Cushion with non-conductive material such as bubble wrap or foam so batteries can’t shift, touch each other, or contact any metal inside the box.
Use a strong, rigid outer box. Corrugated cardboard that stands up to normal handling; anything that collapses under pressure defeats the cushioning inside.
Prevent accidental activation. Turn devices off. Tape over power buttons, or pull the battery out of the compartment and pack it separately in the same box (that still counts as “packed with equipment”).

Required Labels and Markings

Lithium battery shipments need specific markings on the outside of the package. The requirements come from both DOT regulations and USPS rules, and missing them can get a package rejected at the counter or flagged mid-transit.

The core requirement is a lithium battery handling mark: a rectangle with hatched edging, at least 100 mm by 100 mm (about four inches square), with a smaller 100 mm by 70 mm version available for packages too small to fit the full size.⁷ The mark must show the correct UN identification number: UN3480 for lithium-ion or lithium metal batteries shipped alone, and UN3481 for either type shipped with or in equipment.⁵

The mark has historically required a telephone number for reaching the shipper, but that requirement is being phased out by December 31, 2026.⁷ Every package also needs a complete delivery and return address.

Alaska, Hawaii, and Military Addresses

Lithium batteries can be mailed to Alaska and Hawaii under the standard domestic rules, but the ground-only restriction on loose batteries means those shipments travel by surface vessel and can take significantly longer. For intra-Alaska air shipments, small rechargeable lithium batteries are capped at 8 cells or 2 batteries per mailpiece.⁴

Military and diplomatic mail follows international rules, and those are much tighter. You can send lithium batteries to APO, FPO, or DPO addresses only when they’re installed in the device they power. Loose batteries, and batteries packed alongside but not installed in a device, are prohibited. Used, damaged, or defective devices containing lithium batteries are also completely barred from APO/FPO/DPO service, even if they still work. Only new devices in original packaging or manufacturer-certified new or refurbished devices qualify.⁸

International Mail

USPS international rules are stricter than domestic across the board. Lithium batteries can go internationally through USPS only when they’re installed inside a device. The following are prohibited internationally:

Lithium batteries packed alongside but not installed in equipment
Lithium batteries shipped separately from any equipment
Damaged or recalled lithium batteries in any configuration
Pre-owned, damaged, or defective electronic devices containing lithium batteries⁹

Destination countries can impose additional restrictions on top of the USPS baseline. Check the USPS International Mail Manual for the specific country before sending.

Damaged, Defective, or Recalled Batteries

USPS won’t accept damaged, defective, or recalled lithium batteries under any circumstances.⁴ Federal rules allow these batteries to move only by highway, rail, or vessel.¹⁰

Packaging for regulated transport of damaged cells is deliberately conservative. Each damaged cell or battery must sit in an individual non-metallic inner container that fully encloses it, surrounded by cushioning that is non-combustible, non-conductive, and absorbent. The outer packaging has to meet Packing Group I standards, the highest durability tier, and must be plainly marked “Damaged/defective lithium ion battery” or “Damaged/defective lithium metal battery” in lettering at least 12 mm high.¹⁰

Driving batteries yourself to a local drop-off is easier. Damaged batteries headed for disposal or recycling by motor vehicle are exempt from several testing and UN performance packaging requirements, as long as they’re in strong outer packaging and meet basic hazard communication rules.¹⁰ Many home improvement stores and electronics retailers take damaged batteries for recycling free of charge.

When USPS Won’t Take It: FedEx and UPS

Private carriers can ship batteries USPS won’t, including lithium batteries above the 100 Wh USPS ceiling. Both FedEx and UPS follow the International Air Transport Association (IATA) Dangerous Goods Regulations rather than USPS Publication 52, which means different classification tiers and different documentation.

FedEx sorts lithium battery shipments into sections (I, IA, IB, and II) based on battery size and configuration. Higher sections require UN-specification packaging built to Packing Group II standards, a completed Shipper’s Declaration for Dangerous Goods, and a cargo-aircraft-only label, plus a dangerous goods surcharge. Section II covers smaller consumer-type batteries and requires strong rigid outer packaging and a lithium battery mark, but no declaration or surcharge.¹¹ UPS uses a similar framework. For high-capacity batteries in e-bikes, power tools, or commercial equipment, a private carrier is usually the only option.

Penalties for Getting It Wrong

Mailing undeclared or improperly packaged batteries isn’t just a paperwork issue. Federal law treats it as a hazardous materials violation.

Civil penalties for knowingly violating hazardous materials transportation regulations can reach $75,000 per violation. If a violation causes death, serious injury, or substantial property destruction, the ceiling rises to $175,000 per violation.¹² These statutory amounts are adjusted upward for inflation each year, so real-world figures can run somewhat higher.

Criminal penalties are steeper. Willfully or recklessly violating the rules can bring a fine and up to five years in prison. If the violation causes a release of hazardous material that leads to death or bodily injury, the maximum prison term doubles to ten years.¹³ The Pipeline and Hazardous Materials Safety Administration has said publicly that it will pursue violations to the maximum extent the law allows.¹⁴

Even short of prosecution, an intercepted package can be destroyed, the sender can be barred from mailing hazardous materials, and the carrier can open an investigation. The small savings from skipping a proper label or paying for Priority Mail instead of ground aren’t worth it.

1
U.S. Department of Transportation. Check the Box: Is it Hazmat?
2
Postal Explorer. Publication 52 – Hazardous, Restricted, and Perishable Mail
3
Postal Explorer. USPS Packaging Instruction 8B
4
USPS. Can I Ship Lithium Batteries
5
Postal Explorer. USPS Packaging Instruction 9D
6
USPS. Shipping Restrictions and HAZMAT – What Can You Send in the Mail?
7
PHMSA. Lithium Battery Guide for Shippers
8
Postal Explorer. USPS Packaging Instruction 9E – International and APO/FPO/DPO
9
USPS. International Shipping Restrictions, Prohibitions, and HAZMAT
10
eCFR. 49 CFR 173.185 – Lithium Cells and Batteries
11
FedEx. Battery Overview
12
Office of the Law Revision Counsel. 49 USC 5123 – Civil Penalty
13
Office of the Law Revision Counsel. 49 USC 5124 – Criminal Penalty
14
PHMSA. Advisory Guidance – Transportation of Batteries and Battery-Powered Devices