Need info and help installing solar

[SternWake]

Problem with installing is one can cut so many corners to save money and time, and it will work, for X amount of time before Sub par electrical connections fail or one realizes they are not getting even 70% of the expected output as there is so much voltage drop.

For the competent installer it sucks as doing it right, as if it were ones own system,generally takes twice as long as 'good enough' and it is hard to not cut corners if one Underbid or finds that issues arose during installation.

That makes one want to make an estimate, and then double it just for the "just in case' / "i do not want to screw myself" factor.

Since RVs are so mobile, it is likely the owner of the rig will be quite far away from installer, if/when failure occurs from shoddy rushed workmanship using substandard, or underrated parts.

 

[jonsun]

Apparently the big thing is selling mppt then wiring with too long of wires. then wiring controllers with so much excess, too small a gauge, or too much distance the voltage to battery is way too low and they never really charged up. According to bob trojans are supposed to be seeing 14.8v not the standard 14.4v....but even still the controllers are found not even getting that to the battery from the big guys.

But it sells extra panels, expensive controllers, and batteries.

 

[jonsun]

you see the same in the motorcycle world. the shop is hammered every spring with bad batteries. The people with flooded ones wont hook up a tender and the ones with AGM's SWEAR BY THEM. Well the tender cooks the AGM and the floodeds are sulfated.

every year you tell them how to take care of their battery and that they should last 8-12 years. the response is always the same....**** I just replace it every year or two cause its what I've done my whole life and so does everyone i know...OR hooking a sealed battery to a float charge for 6 months is what every website, traditional "wisdom," every bike shop, and maintainer brochure tells them to do....despite reality

nothing will convince them otherwise....even showing the date code on mine from 2005

 

[C-Cat]

I definitely want the wiring to be done properly, that's why I came here and asked for help... should my choice of batteries, panels and charge controller not be up to par, that's obviously on me, but I think it's going to be fine as long as the installation is done correctly!

If you want to know more about what I chose, here's exactly what I ordered:

https://www.amazon.com/gp/product/B01BPLJASU/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B01CGFF8Q2/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1
+ 4x https://www.amazon.com/gp/product/B016EQFD8W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

-Chris

 

[ceejay]

I have solar on my list ( my list is growing even before I actually own it) for my little rig that I put a deposit on .... nice reading all this info ... how do you guys post pictures ... great pic with the water and sunrise in the back ground ... be safe.

 

[galladanb]

Hey C-Cat...
May I ask why you made these specific choices?
Why Poly over mono?
Why the 100/50 as opposed to another?
Why that brand?
Do you know if the Bluetooth device will be a live draw of current or "Ghost Draw"

I am not asking to challenge, but to help me make choices...
I am torn between buying a Kit system or just going the individual component route to get EXACTLY what I want / need...
Would you be able to share any advice in that direction?

 

[C-Cat]

Hey C-Cat...
May I ask why you made these specific choices?
Why Poly over mono?
Why the 100/50 as opposed to another?
Why that brand?
Do you know if the Bluetooth device will be a live draw of current or "Ghost Draw"

I am not asking to challenge, but to help me make choices...
I am torn between buying a Kit system or just going the individual component route to get EXACTLY what I want / need...
Would you be able to share any advice in that direction?

Ok, here's my thought process on these decisions and keep in mind that I am a newbie who only did a bunch of online research, so I don't pretend to be an expert on any of these points:

- mppt is considered much better than pwm (gets more power out of the panels), but costs more... I wanted one that give me room for some expansion and the cheaper ones don't cut it (lucky if you get a cheaper one that does even 30 amp, which maxes out at around 400 watts). Even the 45 amp from Morningstar costs over 100 more than the Victron, which tops out at 50 amp (with 700 watts of total system capability at 12 volts).
- I love the idea of that Bluetooth connection to my phone... I don't even need to get up to check the status of the system (yes, you can call me lazy
- I think the charge controller is a quality piece, from what I've read online, even though it is a European company and not that well known over here
- my choice of panels is a bit of a gamble, but it might pay off... these are China made and I certainly don't consider them top notch, but at 101 USD a piece and decent ratings on Amazon, it did fit nicely in my budget plan; I received them yesterday and they are well made and a quick test shows the correct Voc of around 21.6, so I have good hopes that the gamble pays off. I will report back later when the system is operational.
- I chose poly because it's cheaper, supposedly a bit more forgiving to sun angle and partial shading, but other people might have very different opinions and experience with this.
- finally, individual components will almost always cheaper than a kit

-Chris

 

[C-Cat]

Just an update: We have found help from a wonderful person (Thanks again to GotSmart: the hint with Ehrenberg was perfect) and are making progress with the planning and ordered more parts. I have also been on the roof for the first time today (which is a big deal for me) and wanted to share a first progress picture of our test layout for the panels (we used the cardboard boxes to get an idea of where they will go). If you like, I can share more pictures during the install (near the end of the week).

Thanks much everyone for helping, this forum rocks!

-Chris (C-Cat)

 

[GotSmart]

I am happy that things are working out for you.

The one thing I disagree with is the choice of a poly panel.  In all the spec sheets I have studied, a mono panel will give you about an 8% better power voume than a poly.  With the new bypass diodes, shading is no longer the problem it once was.  

This is something I copied from the Renogy website.  I am not cutting down the panels you bought at all. Any modern panel will do the job for many many years.  Saving $100 each is always a huge consideration when building a large system. There is no wrong answer, just different ways of solving the problem.  

I have a little two panel system, so that difference is more important to me.  You should have penty of power to spare, especially with the Blue Solar MPPT controler. 

• Monocrystalline panels come with high-efficiency cells that help increase module efficiency. Module efficiency: Eclipse 100W Monocrystalline: 18.35%, regular 100W Monocrystalline: 15.47%, 100W Polycrystalline: 14.56%.
  
  
  
• Bypass diodes minimize power drop caused by shade and ensure excellent performance in low-light environments.

 

[C-Cat]

I am happy that things are working out for you.

The one thing I disagree with is the choice of a poly panel.  In all the spec sheets I have studied, a mono panel will give you about an 8% better power voume than a poly.  With the new bypass diodes, shading is no longer the problem it once was.  

This is something I copied from the Renogy website.  I am not cutting down the panels you bought at all. Any modern panel will do the job for many many years.  Saving $100 each is always a huge consideration when building a large system. There is no wrong answer, just different ways of solving the problem.  

I have a little two panel system, so that difference is more important to me.  You should have penty of power to spare, especially with the Blue Solar MPPT controler. 

You're absolutely right about mono panels being more efficient, particularly when it comes to space; they can be much smaller than a poly panel of similar power specs. However, for me it was mainly a price question, since our class A definitely has plenty enough space on the roof. And I would venture to guess that a cheap mono panel could have more quality issues than a cheap poly panel, because monocrystaline is more complicated to manufacture...

 

[GotSmart]

Not really.  A mono is a single slice of material that is grown.  A poli is a slice of cast material.  A simpler process, thus less expensive.  Construction is exactly the same.  

The main difference in quality between the different (expensive / cheap) panels is the construction of the framework.  

This is a good read.

https://en.wikipedia.org/wiki/Solar_cell

 

[DrJean]

Haven't fully scanned the whole thread... caveats about mounting the panels directly to the metal roof as it gets really hot...

change your lighting to LEDs to make a huge difference in needs

make a list of what you want and it's wattage (and surge if any) and total it up to see what you need now and what you will need soon?

Angled panels are more efficient, avoiding having to park the van "just so" and in the sun... portable (not roof mounted) panels allow you to park van in shade and angle panels both!

It won't matter how you do it as long as you're happy with it

 

[C-Cat]

Haven't fully scanned the whole thread...  caveats about mounting the panels directly to the metal roof as it gets really hot...

change your lighting to LEDs to make a huge difference in needs

make a list of what you want and it's wattage (and surge if any) and total it up to see what you need now and what you will need soon?

Angled panels are more efficient, avoiding having to park the van "just so" and in the sun...  portable (not roof mounted) panels allow you to park van in shade and angle panels both!

It won't matter how you do it as long as you're happy with it

Yes, already changed our lighting to LEDs... our wattage is usually between 200-250 to run our work related stuff, drawing around 10-20 DC amps with our inverter... we are installing 400 watts of solar panels with an MPPT controller that has the option to expand to a max of 700w, so we could add 3 more panels later (possibly 2 of them as a ground deploy to give more flexibility).
We are now mounting the 4 panels on tilt mounts, so they will definitely have enough clearance... we have plenty of space on our roof (it's not a van, but a class A diesel).

-Chris

 

[Optimistic Paranoid]

Yes, already changed our lighting to LEDs... our wattage is usually between 200-250 to run our work related stuff, drawing around 10-20 DC amps with our inverter... we are installing 400 watts of solar panels with an MPPT controller that has the option to expand to a max of 700w, so we could add 3 more panels later (possibly 2 of them as a ground deploy to give more flexibility).
We are now mounting the 4 panels on tilt mounts, so they will definitely have enough clearance... we have plenty of space on our roof (it's not a van, but a class A diesel).

-Chris

I don't recommend tilting roof mounts.  If a sudden wind comes along and hits them just right, panels can be ripped right off the roof and destroyed. If you're not getting enough power from your panels mounted flat, you are much better off adding another panel rather than tilting the ones you've got.

 

[C-Cat]

Update: Panels are mounted now and 2awg wires run from a roof combiner box down to the electrical compartment... that was still crazy lot of work for 2 people... but I think we have a chance to finish up tomorrow! 

-Chris

 

[C-Cat]

The panels are up and the cabling is done. Everything seems to work, but it was too late in the day to get any decent wattage... I'll post some more pics tomorrow and report how it works out!