Hi guys. First post. Need some help. I bought a 08 Larson 23LXI last year. I love it but I really have no idea about the battery setup. There's 2 12 volts wired in parallel I assume and connected to a hub that is controlled by an on off toggle switch by the throttle. I'm told the switch is to allow the second battery to charge and to use it when I'm running but I'd like more details than that. The dealer wired it differently this year but I'd really just like to know more about the way its done. I've attached the latest picture with the device the switch operates circled in green. I've also attached last year's wiring. Any help would be appreciated and please feel free to dumb it down for me. Thanks in advance.
Last years wiring:

Last years wiring:
