As stated above, many RV's have no device that charges the chassis/starting battery while rig is parked and plugged into "shore power" . Some recent Winnebagos had Trik-L-Starts installed by their factory. I installed a Trik-L-Start device which diverts some of the converter's charging current for the house battery, to charge the chassis/starting battery (also) when rig is plugged into shore power. I had to run a heavy guage insulated wire from the device in the house battery compartment to the starting battery positive terminal with a circuit breaker because I couldn't find a solenoid device, as mentioned in the installation instructions, on our 2004 Tioga 26Q.
PS: A few RV's come with a "BIRD" device from the factory, to do the same thing as the Trik-L-Start device
