A jump-start kit includes a control unit with a safety circuit and a portable power bank. The power bank and control unit are capable of jump-starting a 12 V car battery as well as charging at least one 5 V portable electronic device. The safety circuit includes a jump-start relay operatively connecting a power supply of the portable power bank to positive and negative jumper cable jacks, a microprocessor, and a voltage input analyzer of the control unit to enable or disable the jump-start relay.