Cargo Trailer Camping Converting

[Wrybread]

What wyebread is recommending is crippled and insufficient.

Poor sunking, so little real world experience with this stuff but still shouting about it. Anyway, parallel wiring is about 2 to 3 percent MORE efficient than wiring in series. I personally wouldn't call that "crippled".

From the manual for the Tracer 4210: image.png


Of course there's a little more loss going from the panels to the charge controller, but that's easy to keep under 3% if you use proper gauge wire, so it's basically even. And that's borne out by my tests. When I switch back and forth between parallel and series wiring when the sun is anything but at it's lowest, I get *exactly* the same watts from my panels. I'll gladly post charts for that if anyone is curious to see.

[Wrybread]

I am not sure why you insist on calling SK that (grandpa)

to be clear, I'm calling him Grandpa Abe from the Simpsons, not just grandpa. I have nothing against grandpas! But Grandpa Abe from the Simpsons has a habit of misunderstanding what people are saying and then screaming at them. Hmm, who does that remind me of?

Speaking of which sunking, if you have different wiring recommendations, please go ahead and make them instead of just shouting incoherently. I linked to that chart because you've been using it, this is the one I usually use, which gives the same wiring recommendations per amperage by the way:

http://www.cerrowire.com/ampacity-charts

[Sunking]

You continue to misrepresent the capabilities of MPPT charge controllers. The Morningstar data sheet you linked says this:

No misreptation. I know that it can be over powered to a limit. That does not mean you should. Secondly using a 100 Voc controller on the 2 panels intended is just plain ignorant limiting the user to only parallel operation and absolutely no room to grow. Why on earth would you recommend anyone doing that?

I absolutely agree that if the S-550 batteries are used, a 40 A charge controller is undersized, and 45 A or 50 A is a better choice. The reason is *not* because there is too much array for the charge controller to handle, it is only because a better design delivers at least C/10 charge current.

Duh Sensij what do you think I have been beating up weybread for? He does not understand the technology. The Morningstar TS-MPPT-60 will allow the user to configure the panels in series, listed with all agencies, will support his battery, and has room to grow. What wyebread is recommending is crippled and insufficient. What is so hard for you to understand? I know why wrebread does not understand, but you should know better.

[SunEagle]

60 years young.

I just hit 64 a few days ago.

[sensij]

One last word on Charge Controllers. Look at a Morningstar TS-MPPT-60. They have a Voc input of 150 volts, max input of 800 watts, battery can be 12 to 48 volt battery, Surge Suppression, and fully listed with all listing agencies including UL, ETL, cETL, CE, SAE and compliant with NEC. Yes it cost more, but will allow you to save on wiring, fuses, and combiners to pay for itself. Not to mention you will sleep better at night not pushing limits.

You continue to misrepresent the capabilities of MPPT charge controllers. The Morningstar data sheet you linked says this:

*Input power can exceed Nominal Maximum Operating Power, but controller will limit and provide its rated continuous
maximum output current into batteries. This will not harm the controller (reminder: do not exceed Voc).

Emphasis mine... putting more PV on the controller and allowing the controller to run at max output will not hurt the controller. Doesn't get any clearer than that. Nominal operating power is not the same as allowable array rating.

I absolutely agree that if the S-550 batteries are used, a 40 A charge controller is undersized, and 45 A or 50 A is a better choice. The reason is *not* because there is too much array for the charge controller to handle, it is only because a better design delivers at least C/10 charge current.

[Sunking]

I am not sure why you insist on calling SK that.
I am actually a Great Grandpa and enjoy being called that. Age doesn't always means stupid or slow except maybe to young "wipper snappers" that don't know better.

60 years young.

[Sunking]

For connectors I highly suggest you cut off the MC4 connectors and use sealed Anderson connectors. Completely weatherproof and waterproof. Connect and forget it. 3-Pole Mini SPEC Plant are made for RV's and Boats along with 4-pole if you intend to parallel panels. You can buy them and premade cables to any spec from Powerwerk.

[Sunking]

Here's a handy chart for figuring your wiring:

https://www.bluesea.com/resources/1437

Use the 3% loss column of the graphic.

If you wire your panels in parallel, that's 640 watts @ 36 volts = 17.7 amps (640/36 = 17.7)

In series, that's 640 watts @ 72 volts = 8.8 amps

Wrong dead wrong. The chart only apples to 12 volt battery circuits. You do not know what you are talking about.

[SunEagle]

Poor Grandpa Abe, ...

I am not sure why you insist on calling SK that.
I am actually a Great Grandpa and enjoy being called that. Age doesn't always means stupid or slow except maybe to young "wipper snappers" that don't know better.

Not that I am calling you young.

[SunEagle]

As far as protecting the joiners, what I do is leave a little space under my solar panels to store it. Since the panels are flat mounted it stays completely dry. Well, mostly.

I agree that your action will protect the connectors as long as they don't sit in any standing water. The problem with using in-line fuse holders is that they need to be accessible which usually means not stuck inside or under a fixed overhang.

While my connectors are under the panels my combiner box is NEMA 4X and is relatively easy to access and change out the fuses. It will cost more then using in-line fuse holders but IMO it is a better installation.

[littleharbor]

As far as protecting the joiners, what I do is leave a little space under my solar panels to store it. Since the panels are flat mounted it stays completely dry. Well, mostly.

For the extra MC-4 inputs on my combiner, that I built, I have just taken unused MC-4 ends and plugged them into the inputs to keep everything from the weather.

[Wrybread]

Poor Grandpa Abe, always misinterpreting things and flying off the handle. If you'd have included my next sentence in your quote of mine you'd see that I specifically recommended he not wire in series:

"So you *should* wire them in parallel to avoid having to worry about that issue (or get a 150 volt charge controller)."

[Wrybread]

As far as protecting the joiners, what I do is leave a little space under my solar panels to store it. Since the panels are flat mounted it stays completely dry. Well, mostly.

[sensij]

I've been really happy with this pre-crimped wire, very easy to connect to the panels:

https://www.amazon.com/dp/B01D7VBJNA...ing=UTF8&psc=1 (I use the 10 foot lengths of 10 gauge, which costs $23)

Cut it to the length you need, and strip the wire to connect it to your charge controller.

I purchase pre-terminated cable as well. I've been buying (and recommending) this seller on Ebay. 2 x 20 ft for $27, or 10 ft for $19. Different reasons to prefer Ebay vs Amazon sometimes, but the cables and terminations appear to be good quality.

[Sunking]

It's a tricky one. I have the same panels as you, and the same charge controller, but I wire mine in series most of the time. There's a chance I'll fry my charge controller

You just admitted you are doing it incorrectly, giving bad and dangerous advice. No other way to spin it.

Urrbanelite if you do not listen to me, then listen to SunEagle, he is telling you the same thing I am. Wyebread is cutting corners and playing with fire pushing the limits. There is no reason you need combiners or fuses between the panels and controllers if you do it the right way. Spend the extra few dollars on equipment made to do what you want and need safely.

Here is the bottom line. I am giving you the same advice I would advise any client. I am a licensed professional engineer with over 300 Off-Grid design/builds in both commercial and consumer residential systems. I am personally responsible for each design. If anything goes wrong like a fire, structural failure, I am solely responsible and liable for my work. I am giving you the same advice I would if you were paying for it. Wyebread is playing fast and loose with numbers he does not understand. He cannot guarantee his work or be held liable.

So here is some things you can consider to work with. If you go with the Rolls S-550 batteries, 2 in series, Ri of roughly 5 milli-ohms which means they can easily handle up to 1000 watt Inverter and be charged with up to 80 amps maximum. They need a minimum charge current of 45 amps to keep them healthy. Batteries and charge currents must be matched to work with each other.

You are going to want a quality Mobile Inverter/Charger, and I highly recommend you buy one that has a built in battery charger, and AC Transfer Switch so you can use shore power to charge your batteries and preform monthly equalization. Additionally if you have shore power, you will not need the solar or batteries. When on Shore Power all your loads will come form shore power and your batteries get topped off by the charger. Just about every factor RV comes equipped with an Inverter/charger with AC Transfer switch. Those Rolls batteries are expensive and you want to protect them. So here are just a couple Inverter suggestions that will fit your needs.

Xantrex Freedom HFS 1055 a 1000 watt model with AC Transfer Switch and 55 amp charger.
Magnum MMS1012 G a 1000 watt Inverter with AC Transfer Switch and 50 amp charger.

As for wiring diagrams I already gave that to you earlier. Actual fuse and wire sizes will depend on that equipment you will use. Regardless the wirring diagram does not change.

One last word on Charge Controllers. Look at a Morningstar TS-MPPT-60. They have a Voc input of 150 volts, max input of 800 watts, battery can be 12 to 48 volt battery, Surge Suppression, and fully listed with all listing agencies including UL, ETL, cETL, CE, SAE and compliant with NEC. Yes it cost more, but will allow you to save on wiring, fuses, and combiners to pay for itself. Not to mention you will sleep better at night not pushing limits.