Off grid solar and AC generator/Inverter combination

[Ray]

Hello my name is Ray. I am installing a solar system on my houseboat. I have 2400 watts of panels. I will be using two Classic 150 controllers in parallel to supply a 12 volt 3600 AH battery bank. The houseboat also has a 12.5 KW AC generator with a Trace M2512 inverter / charger. There will be times when both the solar and the generator will be running. Will there be any problems that I should consider with this system such as 3 power inputs to the same battery bank ( back feeding or harming the chargers/inverter.)
THANKS FOR YOU INPUT. 

[Westbranch]

Hi Ray, can you tell us more about the loads that need to be fed, the type of batteries/ make model and the PV specs, and is that an Inver/charger?, does it by-pass?

[niel]

ray,
i am a little confused as to why you would invest big in every way except the inverter/charger. that is an older modsine inverter/charger and it would be better for you to go with a sine wave inverter/charger maybe like those of the magnum line. there are many other reasons why this proposal isn't good and going 12v with this big of a battery bank is the main one. i'm sure you went 12v because of that inverter and that's your weak link in the whole thing.

i don't know what batteries you are going with, but i'm sure at 12v that it's a nightmare for wiring that many batteries in parallel. it is desirable to have as much of the batteries in series as you can get (48v would probably be the top end for the battery bank voltage) and have fewer of these series strings of batteries in parallel. the wiring must also be set up for equality so keeping wires the same for all strings is paramount. the higher battery voltage may change how you wire the pvs as well, but you may find that 1 classic can handle all of that wattage in pvs at 48v out and it may be borderline for 1 classic at 24v out depending on specifics of the items you have in mind to use. if at a 24v battery voltage you can still use the 2 classics if you've already bought them just to keep them from running at the top end of their ability and would allow for system expandability. at 48v out you already have lots of breathing room and can even expand some with 1 classic. if you have bought 2 then keep one as a spare or see if your retailer will allow the return.

i'll stop here until we get more feedback from you.

[Ray]

Hello Westbranch and Niel (a fellow ham ) You are right about the older Trace. I am going 12 volts mostly because of it. We had tryed a 48 volt plan but where limited to 1200 watts on a 48 to 12 volt converter so that got scraped. There are 6 Grape solar TS-390 panels  3 each in parellel running at 48 volts and 24 amps back to a Classic 150 output 12 volts at 96 amps on each classic. The batteries are eight  Surrette S600 wet cells. 450 AH each set up with 4 batteries for each solar charger. The inverter is wired into the intire eight battery bank( so the eight batteries are electrically interconnected with the solar. The boat will use about 7000 watts per day mostly small to medium loads with the refrig and water pump pulling the heavy loads. Niel your right about the investment, Doing the math I figured it would cost $15 per hour to run the generator. The last owners logs show that is ran 500 hours last year on a rental contract. ...Ray

[niel]

i seem to be missing something here, is there a need for the 12v that you would've had to convert it down from the 48v?

[Halfcrazy]

Niel my guess is it is sort of like a motor home they are highly vested in 12vdc stuff.

Ryan
KB1UAS-AE

[Westbranch]

I'm with Niel, in that it will be far better to upgrade to at least a 24V system using a new TSW inverter.
What equipment other than radio, etc needs 12V?
Do you have heavy 12v loads?
One 12 v battery charged from 24 or 48 should handle small overnight loads.

hth

ps HalfCrazy, if so why the 2500W Inver/charger?

[Halfcrazy]

Well again there will also be a lot of AC loads as well from my experience. That said you could do a 48 volt battery and inverter and have a smaller 12 volt battery that is charged from the 48 but the most common set up I run into is 12vdc system with some 120vac loads.

Ryan

[vtmaps]

The batteries are eight  Surrette S600 wet cells. 450 AH each set up with 4 batteries for each solar charger. The inverter is wired into the entire eight battery bank( so the eight batteries are electrically interconnected with the solar.

I don't understand this... how can each controller only supply 4 batteries?  Aren't the batteries set up as four parallel strings of two batteries each?

Also, I agree with the others that your system is too large for a 12 volt battery bank.  Switch to 24 or 48 volts.  Since you have two controllers you could also have two completely independent systems, one at 12 volts and the other at 24 or 48 volts.

--vtMaps

[niel]

you could still use the converter for any miscellaneous 12v loads, but the ac loads would be accommodated with the higher battery voltage through the sine wave inverter/charger i've recommended you go to. modsine can damage or destroy some items and will cause higher power usage in some as well. items like those with fans, compressors, etc (inductive loads) will be called upon to dissipate upwards of 20% more power due to the wave form and that is in the form of heat.

you would also lessen voltage drop pitfalls with higher voltages.

[Robin]

Hey, I like that M2512 inverter. I designed it in 1991. Of course I still like my bell bottom pants and polyester suit, but my wife won't let me wear them anymore.

[niel]

robin,
no offense, but it is what it is and it's 21yrs later. sine wave inverters are more expensive, but worth it in my opinion.

i liked my bell bottoms too, but i threw them out many moons ago because i wore them out.

be glad she lets you keep them. i'm quite surprised she didn't throw them out.

[Tinman]

Lots of people with RVs or boats use modified sine wave inverters and swapping them out is no small affair when you just want to go to something other than the 12 VDC system designed into the RV (or boat). 

There are very few things that can't run on a modified sine wave inverter. For every time someone had a failure from a modified sine wave inverter, there are probably tens of thousands who didn't.

Have yet to have something fail because of a modified sine wave inverter. That includes computers and related, microwaves, washing machine, reefer, you name it. I wish some of it would go, I could use some new stuff.

[nigel]

Im with Niel on this one, Modified Sinewave will fry lots of things, most modern chargers in phones, and battery based power tools, Bosch, Dewalt  that use a ic  chip rather than a transformer dont last very long. Thats just the start............ Going to 48v single string battery bank is a much better design for equal charging , maintainance and wiring savings also. Anything that needs 12v could be run off a transformer or smaller separate battery, with a AC charger anything that needs high power 12v will always be cheaper to buy and more efficient in AC like refrigerators . Classics will run at 1/4 of the current less stress easier life,    IMHO

Nigel

[Tinman]

Anyone have some proof on that? All those people using phones, TVs (yeah, flat panel), microwaves and computers would be screaming. While there are some you hear about, that isn't the reality for most.

I run mobile phone charges, charge cordless drills, lots of computers, tablets, 3 LCD flat panel TVs of different brands, microwave, washing machine and about everything anyone might normally use, no problem. It isn't like I'm the only one either.

Yes, some of the older mod wines with single steps waves but were talking about good quality, not something from the mid 90s.

I'd change my mind if there was more than anecdotal information. Out of hundreds of thousands of RVs and easily that many boats you don't hear of more than a few issues. Lots of talk about someone said but lets talk real world facts.

As for the drills, easier and less expensive to use a different drill than swap out inverters and redo an electrical system.

I get it and if starting out from scratch would go pure sine wave but just to replace because?

Sorry but while the benefits are there, someone already invested heavily in 12 volt is I'll advised to change just because of opinion. The numbers don't add up.