I've had good luck personally with the Blue Sea ACR. It's automatic and solenoid-based, so while there's some parasitic draw, there's essentially no voltage drop. (The "Sure Power Multi Battery Isolator" seems to be diode based.) They are also bidirectional.
If you'd like, it sounds like you could ditch the isolator, connect the solar to the house bank, use one ACR between each start battery and house battery, and have everything be able to charge everything. This also avoids the potential issues of either trying to make a solar charge controller run through diodes to the battery (though some of ours will, I don't think it's the preferred situation for any MFG), or dealing with differing charge voltages due to isolator diode voltage drops. I believe Blue Sea also makes a newer version with an emergency parallel function, which is regrettably absent on mine. I'm a fan of Blue Sea...my one beef is that, since many of their products are rebranded from other manufacturers, there is no consistency to stud sizes or even nut dimensions, necessitating a way bigger pile of sockets and terminals, and more planning than might otherwise be necessary to get a job done. Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com On Fri, Apr 16, 2021 at 1:28 PM Dave Tedeyan <d...@sungineersolar.com> wrote: > > Hi All, > I am adding solar to a boat, which is new for me. There are three batteries: > one for each of two engines (both of which can also power DC loads), and a > house battery connected to an inverter for AC loads on the boat. All three > batteries are able to get charged from the two engine alternators through a > Sure Power Multi Battery Isolator. We are going to have 4 320w panels and two > FM60 charge controllers. It is a 12V system. > > I would like to be able to use the solar to charge all three batteries. Is it > reasonable to use something like another one of those Multi Battery Isolators > to allow all the solar to independently charge each battery? Is there another > product out there that people would recommend for this? > > Thanks for the help! > Cheers, > Dave > > -- > Dave Tedeyan, PE > > 1653 Slaterville Road, Ithaca, NY 14850 > Cell: 607-288-2898 > www.sungineersolar.com > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
