Intellitec's Bi-Directional Isolator Relay Delay offers a new approach to charging batteries in an RV application. Unlike prior systems that only allowed charging the RV battery from the engine's alternator, the Bi-Directional Isolator Relay Delay charges both batteries when either one is being charged. When the coach is being driven, both batteries will be charged from the engine's alternator. When the coach is plugged into shore power, both batteries will be charged from the converter. If neither battery is being charged, the batteries are fully isolated. The controller also senses heavy loads on either battery to prevent the wrong battery from being inadvertently discharged. The unit is housed in a plastic enclosure for mounting in an engine compartment. It operates in combination with a conventional continuous duty solenoid to connect the two batteries together under the proper conditions. It operates by sensing the voltages on both batteries. When either of these voltages exceeds 13.1 Volts for approximately 2.5 minutes, which happens when either battery is being charged, the control will close the isolator solenoid, connecting the two batteries together, charging them both.