If you have an aftermarket voltage gauge installed, it could be that as well. I had one it my Powerwagon, that would discharge the battery enough in a week, it wouldn't turn over. Not sure why a gauge would do that, but it did.
Good suggestion It did that because it is supposed to be hooked up to a "switched" source meaning it turns off with the ignition switch or it will continue to draw current and drain the battery. We have seen that issue a couple of times ourselves
It did that because it is supposed to be hooked up to a "switched" source meaning it turns off with the ignition switch or it will continue to draw current and drain the battery. We have seen that issue a couple of times ourselves 
