Bob, This is a very interesting idea to have two separate battery banks in series. I find it odd though that this particular motor's datasheet calls for 9 12V batteries. I suppose that I could have one charge controller set for 48V and the other set for 60V. Although this will also pose the problem of trying to run the house loads - if I have two 48V inverters that still leaves one battery that will get loaded less than all the others.
And it seems that everyone else is pointing to the fact that it seems important to keep the neutral and ground internally separated in the inverter in a boat, so I'll stick to marine inverters for this one. Cheers, Dave On Wed, Jun 30, 2021 at 5:30 PM [email protected] <[email protected]> wrote: > > If you can't find a single compatible charger, what also works it to use 2 > (two) separate > > MPPT charge controllers each with a separate PV array inputs and connect > each CC's > battery to half of the battery bank. This has worked fine for both OB and > MNS controllers > in past years and should with others as well I would imagine. Set each > for slightly higher > voltage than 48V of course. > > One thing you may not be able to do might be connecting the chassis > grounds together > depending on how those grounds are tied to the battery negative and > positive lines internally. > > Sometimes the internal SPD MOVs can get in the way if their voltage isn't > high enough to handle > the two PV voltages that are seen as in series from the MOV's standpoint. > But those MOVs are > usually sized voltage wise to handle much higher voltage than, say, 300V > which would he the maximum > voltage both CC's would see for 150V max input controllers. > > You also cannot use the same remote controllers if they are not isolated > from battery minus except for > the controller that is on the bottom side of the battery bank. > > I have seen this method used many times now for 120V battery banks and > also for higher voltage > electric boats. There is quite a bit of this kind of wiring out there as > I remember. > > There are some other standards for marine inverters like, UL 458 marine > supplement and ABYC ratings. > > This includes neutral ground switching like in mobile apps too IIRC. > > Of course, just adding the word "marine" has to increase the price not > matter what the product is. > 😁 > > boB > > > > On 6/30/2021 12:50 PM, Dave Tedeyan wrote: > > Hi All, > > I am going to be working with someone who plans to completely electrify a > boat. The electric motor is meant to run on nine 12V batteries, or 108V. > The motor manufacturer recommends a charger that can run on 120V or 240V. > But has anyone seen a charger that can take solar power and directly charge > a battery bank of 108V? The alternative that I see here is to have two > separate battery banks, one for the motor, and one for house loads. Then we > would have the solar charge a 48V battery bank, and then use an inverter to > charge the 108V battery bank. It seems inefficient, although that may be > the only choice. > > A separate but related question: what is special about a marine inverter? > If there is a 5kw charger for the battery bank, we will need a large > inverter to handle this plus other AC loads, and I am not sure if there are > "marine" inverters this large. And so other than concerns about getting > wet, is there harm to putting a Radian, or a Sol-Ark on a boat? > > Cheers, > Dave > > -- > [image: Logo] <https://www.sungineersolar.com/> > Dave Tedeyan, P.E. > Owner | Sungineer Solar > p: he | him | his > a: 1653 Slaterville Rd. | Ithaca, NY 14850 > w: www.sungineersolar.com <http://www.sungineersolar.com/> > c: (607) 288-2898 > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > 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/[email protected]/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 > > > -- [image: Logo] <https://www.sungineersolar.com/> Dave Tedeyan, P.E. Owner | Sungineer Solar p: he | him | his a: 1653 Slaterville Rd. | Ithaca, NY 14850 w: www.sungineersolar.com <http://www.sungineersolar.com/> c: (607) 288-2898
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