Hello, this is my first post so i will apologize in advance. I have a 2010 Joey weekender 28ft and I am having trouble with keeping my battery charged. How do i find out if my trailer has a charging system? I've had trailers in the past that, when plugged into electricity it charges the battery/batteries. Does every trailer have them or is this something I have to purchase and install myself? If mine has one how do I know, where is it located? Thanks for any help at all.