Electric wheelchair, mobility scooter
Lithium metal (non-rechargeable lithium) batteries are forbidden with these devices.
The battery may remain installed only if it is securely attached to the mobility device, the battery housing provides protection from damage, and the terminals are protected from short circuit. The battery cables may remain connected only if the device is protected from accidental activation. For complete passenger instructions contact your airline. Advance arrangements and extra check-in time may be necessary.
See the regulation: 49 CFR 175.10(a)(17)