Abstract: A battery monitoring and charging system includes a charging equipment and a motor-driven vehicle. The motor-driven vehicle includes a battery, a charger that charges the battery by power supplied from the charging equipment, a charging control device that controls operations of the charger, a communication device that communicates with the charging equipment, a voltage detecting device that monitors voltage of the battery and an activation control device that generates a first control signal if the monitored voltage falls below a threshold value when the charging control device is in off state. When the activation control device generates the first control signal, the charging control device is activated, generating to the charging equipment through the communication device a second control signal that is indicative of a need that the charging equipment should supply power to the motor-driven vehicle and causing the charger to start operation of the charger.

Abstract: A wireless packet stores a plurality of coded words. Each coded word includes user data and an error correction code. Coded word number information indicating the number of coded words stored in the wireless packet, and coding parameter information indicating the coding method used when a coded word is generated are set in the header of the packet.