My customer uses his RV as a stationary winter home. Unfortunately, the RV is not built with a charge circuit for the chassis batteries when the unit is just plugged into shore power so his chassis batteries were always dead. There are many methods to solve this problem, the easiest being a 120vac battery tender connected to the batteries. He did not want something he would have to connenct and disconnect. A Xantrex Echo Charger could also work, but they are also prone to failure and fairly expensive. Winnebago uses a TrikLStart but it is also prone to failure. I chose to install a Bidirection Isolator Relay Delay and replace the stock Isolator Relay Delay installed by Monaco. Thanks for watching!