The Keysight (formerly Agilent) 66319B dual output mobile communications dc source provides two outputs for testing both the main battery power and the battery charger circuitry, allowing customers to test phones and chargers with the same equipment. This feature helps save on rack space (2 outputs in a 1/2 rack box) and eliminates the need for two separate power supplies. Excellent voltage transient response ensures maximum test-system throughput by minimizing device shutdowns due to significant voltage drops in the test wiring. The 66319B includes an Keysight (formerly Agilent)-developed feature that enables cellular-telephone manufacturers to detect permanently and intermittently open-sense wire connections automatically. Detection of open-sense wire connections allows users to prevent incorrect battery-charger calibration, incorrect test results and low-voltage phone shutdown due to a large transient voltage drop. This diagnostic capability helps manufacturers avoid shipping low-quality products and allows for more reliable testing and accurate measurements.