The system does not use Lithium Ion batteries that are the focus of a lot of recent concern, but our shippers and airlines may ask questions about the battery.  ActiveTwo is safe to be put in checked luggage or carried on board aircraft.  It uses sealed, non-spillable lead-acid batteries that are safe to fly.  On the outside of any container in which you ship the batteries (may also be relevant for air travel) include the label "Nonspillable Battery".