The present invention provides a power unit for conveyance, having a main
power source and a standby power source. The power unit has a thermal
battery provided as the standby power source. The conveyance is provided
with an electronic control system and the power unit for conveyance of
the present invention, and electric power for operating the electronic
control system is supplied to the electronic control system from the
power unit for conveyances. By employing such a thermal battery as the
standby power source, the standby power source does not require to be
charged, thereby ensuring a long-term reliability of the standby power
source.