Installed with an isolator, such as the True, AND with the winch connected to the Aux battery, as opposed to the main battery, the winch cannot draw down the main battery so as to prevent proper machine operation. This is important as a 4.5K winch can draw up to 180 amps or so at rated load, that can sap the power of a battery fairly quickly quickly. If possible, it's good to run the engine so the electrical system can at least help supply some of the winch current if that's doable.