Buck, what you said there is the way to go i think. You only have to open one side, either the + or - to isolate the deep cycle from the system. That being said, you would have to run heavy cables to and from the battery, that or isolate them before using the winch. If you were just going to charge the deep cycle, you would only need small 12 or 14 gauge wire, as there wouldn't be all that much current traveling under charging. If you were going to run both batteries in true parallel, you'd need heavy gauge wire , same size or bigger than your winch leads. I'm sure there's a way to do what you said, in the form of a battery monitor. I'll see what I can dig up and put up a link.

 

Thanks Bluethumb - any info that you can dig up is appreciated, as well as many different approaches and options to getting this done. And thanks to all the other guys for the different options and suggestions - keep them coming. We'll figure out a way yet... so that I can have my cake and eat it too. (Heck, what is the sence in having a cake if you can't eat it)... lol