What about can I expect from panels on a cloudy day?

[Mike90250]

With that much panel, you really should be looking at a higher voltage battery bank. Running many batteries in parallel ( since I don't think you are using 2V 400ah cells )

As to your MPPT vs Voltage, you only need 30V of panels to get good MPPT action. Higher voltage just wastes heat in the charge controller, unless you are stuck and can't get all the parallel wire into the conduit.
With more than 2 panels in parallel, you need to have a combiner box, to prevent good panels from backfeeding a damaged panel and starting a fire

I am a bit concerned that you seem to be stating all your panels will be facing west . With several arrays, why not split up the aim and hope some panels get sunlight.

Clouds/fog really cut out the power, if you don't have crisp shadows on the ground, you will not have good harvest. On cloudy/fog/rainy days, my 5kw of panels produce about 300w, so I run my generator then. I do not use an autostart generator.

[chrisski]

Sometimes the most efficient route for charging with the charge controller may not be the best to maximize production.

IME with my RV setup, there may have been a 10% difference between parallel panel output and series panel output, but I did not notice. What it came down to me, is I am “over-paneled” which means I will be done charging by noon. So. Whether it’s in a series configurations or a parallel configuration would mean a real difference of 30 minutes to 1 hour of charging time, which I’m done before then.

One of the sets of panels I have is 600 watts of panels set up 3S2P. For my Victron SCC, the max volts is 100 and max amps is 60. At max production, I have around 54 volts, which is a little much for “ideal” production, but at a loss of about 10%. What had me set them up 3S2P was wire size, voltage loss, and distance. The MC4 plugs I used had a max ampacity of 30, which all 600 watts of panels in Parallel would exceed. Another limit of my MC4 cables were the 10 gauge wire. The next thing I ran into, I wanted to limit voltage loss to 3%, so when I measured how long my runs were and still eating to use MC4 and no thicker than 10 gauge wire and a 3% voltage loss, that forced my setup to 3S2P. With six panels, 6 in series would have meant exceeding the voltage of the charge controller. At no point was the 600 volt rating of my wire ever an issue.

That was the plan. When I installed the panels, I have never received the max 36 amp production from the charge controller to the battery I expected, and that was because of shading. I got around 20 amps tops, and because these panels were flat, not very much at sunrise, but peaked an hour or two before noon and an hour or two after noon.

Shading was a bigger issue thanI thought with the panels. I have a set of portable panels, four 100 watt panels I turn towards the sun through out the day. Since the panels are in parallel, if wiring on one panel goes bad, which it has, the other three panels operate. I was also surprised when I do testing, that when I use my head to shade the panel, even though the rest of the panel is in the sun, the panel output will drop from five or six amps to one amp.

Because of tilting and facing the sun, the portable panels produce max power an additional hour or two before and after the flat panels.

For panels in series, I thought they were limited to the lowest wattage of the one in the series, to include the one shaded in the sun, but it may not be as extreme as I thought. Never tested it.

For cloudy days, where my 100 watt panels would be making 5 to 6 amps in the sun per 100 watts, I would get 1.1 to 1.5 amps per panel. When I had 900 watts of panels, I produced 10 to 15 amps on a cloudy day, andI’ve went up to 1350 watts of panels. I now hope for 13 to 20 amps on an overcast day. I have 3 SCCs for the three different sets of panels I have. With 1350 watts of panels in the sum, I’ve maximized production with 67 amps, but math not taking into account shading and flat panels should put that closer to 85 amps.

[chrisski]

MT50

Tracer 100 amp

2 Centennial 8D 240 amp hour batteries


Debating whether or not to put the batteries in a case and venting that outside.

If they are flooded lead acid I recommend a vent. I did one and not an easy task.

In my RV, my batteries don’t bubble unless I turn the equalization on, and it bubbles so much sounds like a river. On my charger in my house my the same batteries bubble a little.

[chrisski]

Also just noticed you're in the Pacific Northwest. I recommend reviewing the sticky here:

Solar Off-Grid Battery Design - Solar Panels - Solar Panels Forum (solarpaneltalk.com)

Because of your shorter days and cloudy weather, you may need a system 4X my size and 5X the cost to make the same energy I do in Tucson AZ.

[SunEagle]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

I would think the charge will go back to full input if the sun is available and the batteries need to be filled. Although you may not have enough time for a full charge to get to float stage.

Of course an EPever CC may act different but you certainly can test it to see if it starts the charge all over again.

[Ampster]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

You asked about others so I will tell you what my Skybox will do. My charge controller does not use the term boost. Normally my charge settings stay in float for the rest of the day so I can enter the evening with a full pack. I do have a setting for rebulk and that can be adjusted. If it is set too close to the Absorb voltage it will cycle too often. Your charge controller may be different.

[solardreamer]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

You should check the EPEver docs but the ones I have used have a time limit (many hours) for float phase and various voltage thresholds including one to restart the charge cycle. I remember battery voltage has to fall below certain threshold to restart the cycle.

[Mike90250]

Using a recycled metal plate as a electrical mounting surface is a poor choice, IMHO.

[oregon_phil]

Ok. Might start a new thread. My AIMS 3000 pure sine inverter just quit.

I'm about to cry here...not literally but what the heck?

DOA charge controllers etc now I get that working and my inverter quits..

Just past the 30 day return window on Amazon too. Hopefully their warranty process is smooth. If not, then who makes a good quality 3kw inverter?

I don't know what to buy anymore.

I don't know what to buy either, but I'm looking for approximately 2000 watt PSW inverter and appreciate that you document your build. From what you and Chrisski have shown on your builds, I can see that my RV manufacturer can't crimp wire to terminals. I have bought new terminals, crimpers and strippers to redo it myself.

[Mike90250]

Using a recycled metal plate as a electrical mounting surface is a poor choice, IMHO.

Because it's metal or because it's recycled and why?

Because you ask, means you don't understand what can and does go wrong.

Most electrical boxes are metal, with specific engineering constraints built in, like pre-stamped holes, proper spacing for the load capacity of the box, and
the correct finishes to prevent corrosion and electrical leakage. Many are heavy cast metal, not stamped sheet metal. Heavy metal spreads heat rapidly and prevents hot spots from developing fire, thin metal will encourage char behind, where you cannot see it.
People often use plywood, thinking it's a good solid insulator, but it burns. Cement board ( like for a bathtub tile surround) is strong and fireproof, but tougher to work with.

[checkthisout]

I don't know what to buy either, but I'm looking for approximately 2000 watt PSW inverter and appreciate that you document your build. From what you and Chrisski have shown on your builds, I can see that my RV manufacturer can't crimp wire to terminals. I have bought new terminals, crimpers and strippers to redo it myself.

I have a hydraulic crimper that has varying dies. It makes an octagonal-shaped crimp. Then just purchase heat shrink and raw cable and make them as needed.

if your wire is close to the amp limit and you feel the connections getting warm then it doesn't hurt to flood the the terminal with some solder after crimping and before heat-shrink is applied.

[Mike90250]

Ok. What do you think is dangerous about my particular install and what should I do about it?

you should use it away from your main house in case of fire. Have all edges been deburred? insulation rated for the proper temperature and compression ?

[Mike90250]

I caution about using metal for mounting electrical components onto. If you feel comfortable with your skill set, have fun.

[SunEagle]

I caution about using metal for mounting electrical components onto. If you feel comfortable with your skill set, have fun.

I agree. Based on my experience a metal based will eventually get energized due to loss of a ground. That can lead to a shock or electrocution. Electrical equipment should be mounted to non conducting material which increases the ability of being insulated and reduced the electrical path to ground through a human.

[bcroe]

In a lifetime of electronic work, EVERYTHING has been mounted in metal. I have
seen a few connections fail and burn up insulation near them, but the surrounding
metal eliminated fire risk. All here is in metal boxes or conduit, OK to mount stuff
on a concrete wall. YES all that metal is tied into a robust grounding system. Big.
connections bolted to wood make me cringe. good luck, Bruce Roe