Your Apex should of come with a 100W solar system. Stored outside this is enough to keep the battery happy with parasite loads. If stored inside or under that large tree you need to consider other options. With adapters you can plug it into a standard 120V outlet and let the converter keep the battery charged. If no external power or Sun is available you may have to physically disconnect the battery. Depending...your disconnect may not remove all the parasite loads.
I always keep our 5th wheel plugged in to a 120V receptacle 24/7 for months at a time with no ill effects. Our current Surveyor has a 80W solar system and it keeps the battery charged and happy. We never turn the disconnect off and it is stored under the Florida sun. Towing it all day with the 12V compressor refrigerator on we always reach our destination with a charged battery.
Your battery(s) need to match your lifestyle.