A leakage detection system for a battery pack of a vehicle may include detection circuitry having a first side connecting a positive terminal of the pack to ground and a second side connecting a negative terminal of the pack to ground, and including no more than one switch among the sides. The system may also include measurement circuitry configured to measure a voltage across a resistor of one of the sides when the switch is open and closed, and a controller programmed to output a leakage associated with the battery pack based on the voltage.