Battery Maintainer

I'm looking at the Battery Tender and I see they have one that has four separate charging units. I think the problem I have with my current one (which is a Battery Tender Model) is it's a single 12 volt charger and I'm hooking it to one battery, but both batteries are connected to each other. So I'm wondering if with their four batter unit, can I hook one to each of the chassis batteries and will it work even with leaving the batteries hooked to each other? I'm trying to avoid having to disconnect batteries. I take fairly good care of my motorhome and I go to it at least once a month and make sure it gets started and driven around. I don't want to be messing with connecting and disconnecting batteries. I just want to unplug it an go.

Not to mention I used a battery tender on my Harley Davidson and I got 9 years out of the original battery. So I want to use a battery tender on it.