Have 2017 Thor ACE, battery dead, jumped started and let run for about an hour. Unplugged from 30amp electrical while in RV barn. Few days later went out to Thor and discovered house batteries are dea...
Have the battery load tested - most auto stores for free. New batteries fail or they are abused.
I installed a battery disconnect switch on the battery post on both banks so that every thing is disconnected. I also fully charge the batteries every month even though they will be OK for many months disconnected.