inverter/charger

Typically, coaches have a relay which closes a circuit when the engine is on that allows the vehicle alternator to trickle charge the house batteries. Once the vehicle is turned off, that relay opens and the vehicle electrical system is isolated from the house electrical system. In this structure you'll have an emergency start or auxiliary start button on your dash. That button closes a relay which allows the vehicle to start from your house batteries. The idea is that if you have been parked for some time, maybe you have had shore power or maybe you have run your generator, but your house batteries are full, you can start your rig with house batteries and get going. This is the historical way most coach builders have provided for any interconnection between house electrical and engine electrical. Ideally you want the two systems to be separate from each other.

Unless a previous owner has modified this electrical structure, you should assume that your chassis battery is not connected to the house charging system except for the situations I detailed above. The Trick-L-Start would resolve this limitation for you.