Got a 2014 Winnebago Journey with a 6500 Onan in it. I also have just under 700 watts of solar. We use a lot of power, mainly the residential fridge. After 2-4 days the batteries will drop to 12V so generator is need to give them a boost. I have changed my routine to charge the batteries in the morning while I use the coffee maker. I do stove coffee too but if I am going to run the genny I take the easy way out.
Also have the need for the genny on those days where its cloudy or I am near trees and get shade at certain times of the day.
The Onan has an option for automatically charging the batteries when they get low and shut off at a preset voltage. I had a hard time determining at what point to shut the genny off. Well I have finally watched my inverter/charger as it gives me a readout of the charging amps for the battery. I have determined that I need to be at 13.9V on the Onan, as that is when the charger starts to decrease its charging rate. At this point I have decided to shut the generator off and let the solar take over. Not going to do this everyday while boondocking, but I wanted to get my best bang for the $ using my generator, no need to use gas to charge batteries that are near full. I have the on/low setting at 12V.
Just curious to what others have found.
FYI, Please, don't tell me to put in LED bulbs or use less power. Already got LED bulbs, put switches on all 3 LED TV's so they do not draw power even when they are off, disabled the illuminated switches at the electrical panel at the steps where you come in as well as replaced the bulbs in the RV that were not LED from the factory.