A portable charger capable of jump starting a 12 V car battery includes a charger battery, a jump start circuit operatively electrically connected with the charger battery and with an ignition power outlet, and a microcontroller for coordinating safety functions to establish or interrupt the operative electrical connection of the jump start circuit with the ignition power outlet. The ignition power outlet comprises a positive power socket, a negative power socket, a positive sensing socket and a negative sensing socket. The sensing sockets are electrically isolated from the power sockets, and the microcontroller senses voltage across the sensing sockets and is configured to interrupt the operative electrical connection of the jump start circuit to the ignition power outlet until proper voltage is sensed across the sensing sockets.