Solar panels / charger doing what it is supposed to?

[Headhunter]

Not a Newmar but I have three factory solar panels installed on my 2021 Tiffin 33 AA. I was getting weird readings, and messages saying charge full or something like that for the first 8 months of ownership. I did have a separate solar panel manual that came with the coach. I don't think the panels ever truly connected to the controller correctly. Finally some one at the dealership figured it out and they replaced my controller. Problem finally solved.

HH

 

[MarkMaxPayne]

I gave up waiting for Newmar support to respond beyond "our engineers are still looking at it." Last night I ordered a Victron SmartSolar MPPT 150/70-TR on Amazon and to my surprise it showed up this morning!

Spent a couple hours swapping out the Xantrex C60 (which is designed for lead acid and Nicad, not lithium) and I NOW HAVE WORKING SOLAR CHARGING!

I changed its settings via the Victron bluetooth app as per the recommendations made by Lithionics (makers of the lithium iron phosphate house batteries Newmar also installed at the factory).

One mod I made was I added a circuit breaker as per U.L. rules between the solar panel wires and the charge controller so I could turn off and isolate the panels anytime I may want or need to.

Given the impropper solar controller was installed at the factory I will update the post if/when I get a response...

My word of caution if your new Newmar has both the lithium and solar options on the build sheet: verify the solar charge controller they used is actually meant for lithium...

Best,
-Mark

 

[Richpatty]

Unbelievable. I hope they reimburse you in some way…

 

[Kevin D Pem]

Unbelievable. I hope they reimburse you in some way…

@Neal Should send a design house fee for engineering costs

 

[Rich W.]

I gave up waiting for Newmar support to respond beyond "our engineers are still looking at it." Last night I ordered a Victron SmartSolar MPPT 150/70-TR on Amazon and to my surprise it showed up this morning!

Spent a couple hours swapping out the Xantrex C60 (which is designed for lead acid and Nicad, not lithium) and I NOW HAVE WORKING SOLAR CHARGING!

I changed its settings via the Victron bluetooth app as per the recommendations made by Lithionics (makers of the lithium iron phosphate house batteries Newmar also installed at the factory).

One mod I made was I added a circuit breaker as per U.L. rules between the solar panel wires and the charge controller so I could turn off and isolate the panels anytime I may want or need to.

Given the impropper solar controller was installed at the factory I will update the post if/when I get a response...

My word of caution if your new Newmar has both the lithium and solar options on the build sheet: verify the solar charge controller they used is actually meant for lithium...

Best,
-Mark

Huge improvement - quality, dependable controller, and the ability to monitor via blue tooth. Nice install too. It would be nice to get Newmar to compensate, at least the cost of the OE controller (probably a lot less than the new Victron) but now it‘s done right and thats the most important thing.

 

[Joe Hogan]

We had a Victron charge controller in our RV. Very nice equipment and easy to use. The Bluetooth features make it very convenient.

 

[Neal]

Last night I ordered a Victron SmartSolar MPPT 150/70-TR on Amazon and to my surprise it showed up this morning!

Glad you got this working!

I hate asking this knowing you bought something already but how did you choose this one over others? Several of us here use the 150/100 Tr which means a 100 AMP current cap where yours is 70 AMP. I can pull in 100A from my panels. 70 AMP should be fine too but just wonder if sizing larger for capacity is something to consider?

Amazon product ASIN B08LBVYTXD

 

[MarkMaxPayne]

Glad you got this working!

I hate asking this knowing you bought something already but how did you choose this one over others? Several of us here use the 150/100 Tr which means a 100 AMP current cap where yours is 70 AMP. I can pull in 100A from my panels. 70 AMP should be fine too but just wonder if sizing larger for capacity is something to consider?

Amazon product ASIN B08LBVYTXD

Thanks! I sized it larger based on knowing I'll want to add a 3rd Lithionics battery and additional solar at a later date (I may even replace the 4 flexible 100W GoPower panels that came from the factory someday as they just are not as good as glass panels). I wanted to make sure I had headroom to grow into. At this time I've altered the 150/100 Tr settings to lower the cap.

Best,
-Mark

 

[Neal]

You said you bought the /70 which is not larger than the one I have and linked.

 

[MarkMaxPayne]

You said you bought the /70 which is not larger than the one I have and linked.

Ah, sorry. I missed that. I sized it based on the panels / load I expect to grow into vs. going "all in" as I don't boondock for days on end (a day or two tops). Part of my reasoning was also based on the sizing of the wires Newmar ran from the roof to the bay. Yes, I could rewire everything up top to be in series vs parallel (the factory tied all of them together in parallel) or series/parallel, but...
You'll see my 4 100W GoPower panels were sending only ~18A in full afternoon sun and only ~21A to the batteries.

I may regret not going to /100 someday, but it should cover me for the next few years.

Best,
-Mark

 

[Kevin D Pem]

Because you asked @Neal my system is based on 60 amp controllers.

Why you ask??
A 60 amp controller will handle 720 watts of panel at 12v, 1440w at 24v. This means I have back-up if failure occurs. I know that is my sailor mentality, but just the same! Sometimes controllers are a week or more away.

But there is a better reason to use smaller!!! Because he who dies with the most toys wins!!! OK, just kidding. Shading just one cell on a panel kills the power of the whole panel. Well I have more bad news. The complete system can be compromised. Imagine back feeding one cell with your entire 1800 watts!!!

So where a possibility of Shading is present, I have split the power between several controllers. I have 4 controllers in my system.

More directly because Shading is such a big issue on a RV, many smaller controllers are the way to go!!! And yes 100 amp Controllers would do the job, smaller will also do the job at a lower overall cost.

 

[Joe Hogan]

We had around 12-1300w of solar installed and mid day could generate 1100 or so watts to the battery. We opted for a higher voltage configuration to avoid overheating the pre installed Newmar solar prep wires.
As you can see we easily exceeded 75amps to the batteries.

 

[Kevin D Pem]

We had around 12-1300w of solar installed and mid day could generate 1100 or so watts to the battery. We opted for a higher voltage configuration to avoid overheating the pre installed Newmar solar prep wires.
As you can see we easily exceeded 75amps to the batteries.

View attachment 19104

Wow, those are exceptional numbers! Because I don't have the charts in front of me. A 100a controller is rated for ?1360? Watts of panel at 12v?

 

[Rich W.]

You can always run two with a second string of panels.

 

[Kevin D Pem]

You can always run two with a second string of panels.View attachment 19119

Yah, you can even run different sizes panels on the second controller with no issues.

 

[Rich W.]

Yah, you can even run different sizes panels on the second controller with no issues.

I hadn’t thought of that. I just run two 315s on one string and three on the other. I also ran 14ga for my panels and abandoned the factory 6ga “solar prep”. One of the benefits of residential panels.

 

[Kevin D Pem]

I hadn’t thought of that. I just run two 315s on one string and three on the other. I also ran 14ga for my panels and abandoned the factory 6ga “solar prep”. One of the benefits of residential panels.

Yah I use 10awg, with two panels in series. On the roof wires. Still running 6awg from the cargo panels. Less losses.

 

[Rich W.]

Yah I use 10awg, with two panels in series. On the roof wires. Still running 6awg from the cargo panels. Less losses.

Panels are 33v, 9a so not much loss. Another benefit of residential panels. I like the idea of filling in with a string of smaller panels on another controller (I have one more 150/35 in stock) - maybe some 200w or so panels where my 315s wont fit. I could probably add another 600w pretty easily.

 

[Kevin D Pem]

Panels are 33v, 9a so not much loss. Another benefit of residential panels. I like the idea of filling in with a string of smaller panels on another controller (I have one more 150/35 in stock) - maybe some 200w or so panels where my 315s wont fit. I could probably add another 600w pretty easily.

Like I said. I use 60 amp controllers. I can keep the numbers in my head for easy access. I have both 24 and 12 volt system. This means having the numbers in my head and consistent equipment keeps me from making as many mistakes. But a good understanding of the equipment makes for a mix and match environment.
I think you're on your way!!!

My panels are used 240 and 250w panels they are 60 cell panels as are yours. Mpp is 29.? Or 30.0 as I recall. That of course is charge voltage for lead acid, so no room for a cloudy day. So I run 2 panels serial to get 60 v mpp. My controllers will handle??? Higher voltage than the open voltage so that works reliably. The cavit is an mppt controller is a smart buck converter, and that means for efficiency the voltage in vs. out, should be limited to 2.5 times. 40 v in 15 out. So when I work on my 12 volt system the array is paralleled 30 in 15 out. Everything including wire needs to handle the loads at minimum loss. Because my system is built for redundancy in case of a failure, all such components have to work on 12 volts, reliably.

Did you know that if you have a house panel (affectionately called a 24v panel) and a 12v panel, if the cell size is the same on both panels you can tie them together in series??? Just gave you another answer for limited real-estate.

 

[Rich W.]

I toy with the idea, but for what I do my current system is basically enough - 1575w gives me a nice capable battery charger and on this rig thats all it is. On my Bay Star the solar was a little more involved and would run an AC all day and then on the battery bank (Li-ion) for around 8 hours after sundown. That was nice but in hot climates not enough, and to double that meant a much bigger battery bank. I chose to just stay out of hot weather and reduce my boondocking aspirations.

Pics are the inverter and battery in my Bay Star. Before that I had almost 2kw of solar on an old Class C (there wasn’t as much other stuff on the roof).

This was from the class C with all this equip stuffed below the two dinette seats (the other side was all battery). I charged the battery bank to 32.8 but the 24v inverter would only go to 28v so the balance could only be made up by solar. I enjoyed that system but these days I’d rather just keep it simple. Also the “quiet diesel” generator on my current rig is much more tolerable than the old Onan.

This is with an AC running while charging the battery bank at 17.9a on solar only - no grid power.