The DC Load is a two terminal device that can be connected to DC sources. Here, a DC source is a voltage that is always positive on the DC Load's + terminal referenced to the - terminal. DC Electronic Loads are used for design, manufacturing and evaluation of DC power supplies, batteries, and power components. Other applications include fuel-cell and photovoltaic cell test. The DC Load can operate under the following modes: • Draw a constant voltage from a DC source. • Draw a constant current from a DC source. • Draw a constant power from a DC source. • Present a constant resistance to the DC source (this behavior simulates a perfect resistor whose resistance doesn't change as a function of current or voltage). The DC Load can present dynamically changing loads to the DC source with millisecond switching times. The DC Load can be remotely programmed via a serial interface (RS-232 or USB). Versatile triggering options allow the dynamic load behavior to be synchronized with other events. A battery test mode is provided that will measure the ampere*hour (A*hr) characteristic of a battery. Shorts can be simulated by either the front panel or custom programming. The DC source or other components can be protected from excessive voltage, current, or power, which will cause the DC Load to shut down if excessive levels or reverse polarity are detected. Dynamic profiles and last instrument states can be stored in non-volatile memory. The DC Load is a versatile instrument for static and dynamic testing of power supplies, batteries, DC to DC converters, and battery chargers.