Flying with a battery is possible under certain conditions. First, it can not be included in checked luggage. The battery must be removed from the scooter and brought as part of your carry on baggage. This is a strict rule with all domestic and international airlines.
Also, per FAA, since the battery pack is over 100 Watt Hours, some airlines will want to inspect the battery before allowing you to proceed through security. The Levy battery is 230 Watt Hours, and the Levy Plus battery is 374 Watt Hours. Please double check with your specific airline before bringing it with you to make sure this is acceptable, as rules can frequently change regarding allowable battery sizes.