Originally Posted by code2e
Your engine (chassis) battery should be charged while on shore power. If you have a voltmeter, you can check it. A fully charged chassis battery should be 12.6 volts at its terminals, without any load or charging applied to it. If it is being charged, voltage should be 13.4 to 14.2 volts.
Coach prioritizes house batteries for charging before any charging of chassis. I like to use a Battery Tender on the chassis battery to be sure it stays ready.
As for generator time needed. There are so many variables. How much amperage used from batteries for how many hours? How much charging amperage to replenish batteries? Your voltmeter will help you learn. Battery pack needs to charge to 12.6 volts across whole pack. Measured an hour or so after charging stopped. Try not to draw battery pack below 10 volts before charging. Your usage will determine generator need. Battery tender will see to the chassis battery while onboard charger does coach batteries.
Thank you for the input
I have a battery Tender connected to the chassis Battery in fact that was the main reason for my question
I installed since my previous Class C didn't charge the battery while it was connected to shore
So after a few months using the Tender I was wondering if this was necessary
I understand about the Generator
Since I'm in Fl I can't boondocking while the temperature is over 70°
But plan is as soon temp drops a little I will spend 24 hr without power to check how much will be left on the battery and how long to get a full charge
All this cause we planning a long trip with many days boondocking
Thanks again for the info