POWER SUPPLY CIRCUIT AND METHOD, AND VEHICLE EMPLOYING CIRCUIT

A power supply circuit for stably supplying power to loads of a vehicle comprises a battery pack, a switch circuit, a first control circuit, a detection circuit, and a second control circuit. The first control circuit is configured to output a first control signal to turn on the switch circuit and the battery pack can supply power to the loads when the vehicle is in a first state. The detection circuit is configured to detect whether the first control circuit normally outputs the first control signal during the first state and output a trigger signal to the second control circuit in response to the first control circuit does not output the first control signal. The second control circuit outputs a second control signal according to the trigger signal to control the switch circuit to be turned on. A power supply method and the vehicle are also disclosed.