 Unwilling to delay the aircraft's scheduled takeoff for Miami for several hours, Linquist said the batteries would be recharged by the aircraft's generators "en route".Linquist taxied NC16002 to the end of runway 27 for takeoff, but stopped at the end of the apron due to lack of two-way radio communication.Although capable of receiving, Linquist reported to the head of Puerto Rican Transport, who had driven out to the aircraft, that the radio could not transmit because of the low batteries.