There is a limit of two spare batteries per person for the larger lithium ion batteries described above (101–160 watt hours per battery). Batteries must be protected from damage. Battery terminals (usually the ends) must be protected from short circuit (i.e., the terminals must not come in contact with other metal).

Yes, you can fly with power tool batteries, but they are subject to strict "High-Fidelity" safety regulations regarding their chemistry and capacity. Spare (uninstalled) lithium-ion batteries must be carried in carry-on baggage only; they are strictly prohibited in checked luggage due to the risk of fire. Each battery must generally not exceed a 100 Watt-hour (Wh) rating. For larger batteries (between 101 and 160 Wh), you can typically carry up to two spares, but only with explicit airline approval. Batteries exceeding 160 Wh are prohibited on all commercial flights. If the battery is installed in the tool, the tool can be placed in checked baggage, provided the device is protected from accidental activation and the "High-Fidelity" switch is locked. It is a high-fidelity requirement to protect the battery terminals from short-circuiting by placing them in their original packaging, a battery case, or by covering the terminals with electrical tape. Always check with your specific carrier in 2026, as some airlines have additional high-fidelity safety restrictions.