Very new to solar but started purchasing items, not sure of the final specs of the whole system.

[Hedges]

Instead of running the cable direcly to one battery terminal I thought it would be beneficail to add a second plate or tap this plate. I would add the battery connection so it would be in the center of the 3 inch plate. In the 3rd picture I would add the connection in the middle of that plate slightly forward.

If a 3" plate joins 4 cells at the end, it seems pretty well balanced. Two cables with their own bolts to the place between cells 1 & 2 and between 3 & 4 would be perfectly symmetric.

Interesting monitor boards, separate one for each cell. Are they powered by the local cell? Do they communicate to the next cell's board with a slight voltage offset, or all communicate on a bus as much as 48V away?

When I was top ballancing the batteries I moved it often as the cell directly connected to the charger increased faster. Since I have not watched a 4p16s charge up I'm just pondering ideas to achieve the best possible outcome.

So that was when parallel balancing a large number of cells all at once? Could be contact resistance, but I don't expect much between bolted electroplated copper bars (only contact to the cell). The final configuration should have very little problem. Unless one cell has poor contact, in which case three cells in the 4p get all the current.

 

[Hedges]

These are different than the ones I watched people use on yt for midnite installs, they do not come with the threaded ring. They expect your box to be threaded, If you think these will cause significant issues I can swap them out and order the ones online?

https://www.lowes.com/pd/Sigma-Electric-ProConnex-1-2-in-Uf-Cable-Connector-Conduit-Fitting/1087617

You can add nuts on the threads to clamp to a sheetmetal box like that

https://www.lowes.com/search?searchTerm=conduit+nuts

... and plastic bushings so no metal edge to cut into insulation.

https://www.lowes.com/search?searchTerm=conduit+bushing

 

[Supervstech]

These are different than the ones I watched people use on yt for midnite installs, they do not come with the threaded ring. They expect your box to be threaded, If you think these will cause significant issues I can swap them out and order the ones online?

https://www.lowes.com/pd/Sigma-Electric-ProConnex-1-2-in-Uf-Cable-Connector-Conduit-Fitting/1087617

Well, since the box is outdoors, the connectors should seal to the box... they make these fittings with a rubber seal to lock out moisture.
At a minimum, I would get the lock rings, and reposition the fittings to get a better seal.

 

[Hedges]

Box isn't gasketed, probably 3R drip-proof. (It resembles a combiner I have.)
The wire connectors are on the bottom so gaskets there don't make any difference.
The Midnight surge arrestor on the side benefits from a gasket so water doesn't enter there.

If those are compression fittings, they use a gasket to seal to the wire, but were intended for threads to seal if used with a waterproof threaded box. They don't have a shoulder for a gasket making waterproof seal to a sheet metal box (but doesn't matter on bottom of this box.)

 

[kromc5]

If a 3" plate joins 4 cells at the end, it seems pretty well balanced. Two cables with their own bolts to the place between cells 1 & 2 and between 3 & 4 would be perfectly symmetric.

Interesting monitor boards, separate one for each cell. Are they powered by the local cell? Do they communicate to the next cell's board with a slight voltage offset, or all communicate on a bus as much as 48V away?



So that was when parallel balancing a large number of cells all at once? Could be contact resistance, but I don't expect much between bolted electroplated copper bars (only contact to the cell). The final configuration should have very little problem. Unless one cell has poor contact, in which case three cells in the 4p get all the current.

The boards are the batrium watchmon m8, they are each cell, they do get power from each cell also. The watcmon controller is also powered from the battery and has a very large input range. It can be powered via usb for the initial configuration but it does not provide the powered needed for full use. The watchmon m8 can balance up to 28 ah/day seemed decent compared to other ones I researched. The software is what I really like and it is wifi enabled.

 

[kromc5]

You can add nuts on the threads to clamp to a sheetmetal box like that

https://www.lowes.com/search?searchTerm=conduit+nuts

... and plastic bushings so no metal edge to cut into insulation.

https://www.lowes.com/search?searchTerm=conduit+bushing

Thank for the links I will go and get them.

 

[kromc5]

I looked into many types of fire systems and found this one as it is the most simplistic design. I was thinking of have a couple of the 6lb in the breaker room and two more over the batteries. When trying to see the likelihood of fires I did not find much except odd reports of actual solar panels catching fire. But I kept those decently way from the house including the combiners just in case. Anyone else have a fire suppression system?

WatchDog Automatic Fire Extinguisher

 

[Hedges]

fhorst has a couple fire protection related schemes.
One of his ideas I liked was a smoke alarm which disconnects power.
Best thing to do when you have an electrical fire is shut off the electricity; otherwise it can reignite things.

Ideally, one would have a way to detect overheated connections and do the same.
IR imaging, distributed thermistors wired together, or ...
Of course BMS can detect poor contact between cells. Probably disconnects at high voltage, then reconnects, repeat? Ideally latch off.

Keeping explody batteries away from the house would be wise. That will be code in the future, unless UL listed.

There have been reports of non-LiFePO4 lithium batteries burning. One was a cargo-container sized system. There were some LG RESU-10H batteries recalled for same reason (see "UL listed", above).

 

[kromc5]

fhorst has a couple fire protection related schemes.
One of his ideas I liked was a smoke alarm which disconnects power.
Best thing to do when you have an electrical fire is shut off the electricity; otherwise it can reignite things.

Ideally, one would have a way to detect overheated connections and do the same.
IR imaging, distributed thermistors wired together, or ...
Of course BMS can detect poor contact between cells. Probably disconnects at high voltage, then reconnects, repeat? Ideally latch off.

Keeping explody batteries away from the house would be wise. That will be code in the future, unless UL listed.

There have been reports of non-LiFePO4 lithium batteries burning. One was a cargo-container sized system. There were some LG RESU-10H batteries recalled for same reason (see "UL listed", above).

I will dig into the batrium manual and software to see if I can have it monitor external temperatues.

 

[kromc5]

Here's the 2/0 cable that I purchased off of ebay arrived yesterday: no response from seller yet, let me add another

 

[kromc5]

Tried out the tapping feature on the nova, It does decent job but due to how it load senses it does not always auto reverse.

 

[kromc5]

Finished the breakers, power distribution each batrium/dcdc converter will each be on separate breaker.
You can see the supply voltage on the righ / lower.

 

[kromc5]

Brought one 12kw online today and setup the wifi and connected it to the growatt server. Decently straight forward the cell app did not work. Logged in directly to the wifi and connected it manually to the router, the default server port is 5279, I setup port forwarding but I have not tested to see if this was really needed or not. I will turn that off in the router later and see if it still functions. Left the wifi module in default dhcp as I wanted to keep it simple for the testing.

The web interface is nice and it auto updated the firmware on the wifi module which was required to modify the growatt internal settings.

The key to save is the date and the format is 20210604 which can bee seen in the pictures.

default growatt settings — Postimages

postimg.cc

default growatt settings — Postimages

postimg.cc

default growatt settings — Postimages

postimg.cc

default growatt settings — Postimages

postimg.cc

 

[kromc5]

Brought a couple panels online for more testing.

default growatt settings — Postimages

postimg.cc

 

[kromc5]

Few pics of the firmware update process on the inverter.

 

[kromc5]

Wondering if anyone can answer a question about the wiring.

screenshot 7 — Postimages

postimg.cc

I have taken a bunch of pictures and sent to signaturesolar, I really want to make sure I understand it all before attempting any load testing.
I found this video where they did hookup neutral. The manual only shows h1/h2, I do not have utility coming in.

 

[kromc5]

I talked to signature solar today, was told neutral is required, I was told if charging from the grid or generator the neutral should not be connected.

Udpated:
Second call went better but my first test created an odd issue they have not seen and will require further testing.

 

[kromc5]

Not sure if anyone has heard of this, I'm getting proper output 113v, 110v measured on main legs of the breaker. Soon as one breaker is turned on that goes to the outlets in the tv that has a fan attached one leg goes to zero and the other goes to 240v.

 

[kromc5]

Growatt Support Line in case someone might need to call in the future: 1866-686-0298

 

[kromc5]

Eye of Sauron came into today: IE Wixey WL 133

Now I can use the auto start-stop function, I get decently close to the hitting center but this will help speed up the next 256 holes I have to drill.