Abstract: There is disclosed a climate controlled vehicle 11 comprising: a prime mover 21; a transport climate control unit 14; a vehicle power network 204 comprising: an alternator 205 configured to be driven by the prime mover when the prime mover is active, a primary battery 210 electrically connected to the alternator for charging; a secondary battery 211 electrically connected to the alternator for charging; power supply terminals 207 connecting the vehicle power network to the transport climate control unit; a switch 206 having a closed configuration in which the primary battery and the second battery are electrically coupled to the alternator for charging and an open configuration in which the secondary battery and the power supply terminals are isolated from the primary battery to prevent power supply from the primary battery to the transport climate control unit.