XW Automatic Generator Start Questions

alter

Hello, I have a small 4 panel 840 watt system hooked up to a Xantrex XW charge controller setup with a bank of 4 6v batteries. Its working well but sometimes the battery bank gets too low and I need to charge it manually using a battery charger that I have hooked up to a small generator. I'm looking to upgrade this system by adding an "automatic start" generator that can be automatically started when the battery bank needs a charge. I've heard of the "XW Automatic Generator Start" unit and from what I can tell, Its supposed to be able to trigger the start of one of these generators. I'm unfamiliar with this and was wondering if anyone else on this board has successfully done something like what I'm trying to do, and if so, would I be needing much more than an automatic start generator and the XW automatic generator starter? Can the XW generator starter also tell the generator to shut down when the battery bank is full, or if not what would be needed? Thanks!