Any tips on my setup?

[Sunking]

Both your premises are wrong.

No they are not. My premise is spot on; your equipment is incompatible and you do not know what you are doing.

You came wanting your system critiqued and you got exactly what you asked for. Now you want to moan about it because you did not like what you have heard from me and everyone else in all threads you have mucked up. You found out you do not know near as much as you think you do. The 4 to 5 engineers telling you that have close to 200 years of professional experience working with solar in one form or another. You have 20 years working under a shade tree on an RV.

Nothing more, nothing less. If you want to make compromises that are not necessary, that is your problem. I have been thanked 6 times today. How many times have you been thanked since you have been here?

[Wrybread]

No they are not. My premise is spot on; your equipment is incompatible and you do not know what you are doing.

Sorry, but not everyone here thinks my equipment won't work, just you. And sorry again, but you've been told by those other posters that you're wrong. As Sensij told you with superhuman tact:

However, there are some points in dispute in this thread that do not appear to be your finest work, and I've tried to chip in some clarifications. Time to move on to the next one, don't you think?

Let me know if you need me to translate that for you. Believe me, it would give me great pleasure to do so.

And furthermore, your alarmist and offensive language (not only to me) is way out of proportion with the topic.

You came wanting your system critiqued and you got exactly what you asked for. Now you want to moan about it because you did not like what you have heard from me and everyone else in all threads you have mucked up.

Wrong yet again. I got a ton of good info from this thread that significantly changed my plans. What infuriates you is that none of that info came from you.

If you want to make compromises that are not necessary, that is your problem.

I figured out a perfect solution: you buy me the $600 Outback charge controller, and I'll use it. Sound good? No? Ok, I guess the compromises are necessary then. For now at least.

I have been thanked 6 times today. How many times have you been thanked since you have been here?

Is there a 12 year old boy hiding somewhere in there?

And if this forum had a thumbs down button, what do you think your score would be?

[Sunking]

I figured out a perfect solution: you buy me the $600 Outback charge controller, and I'll use it. Sound good? No? Ok, I guess the compromises are necessary then. For now at least.

Could not agree more with you. If it had been me in your shoes I would have spent the extra $150 on a Morningstar TriStar 45 amp controller that can input 600 watts with a 150 Voc input allowing me to connect the panels in series and not have all that incompatibility. That is what I would have done because I know what I am doing. No compromises needed.

[Wrybread]

If it had been me in your shoes I would have spent the extra $150 on a Morningstar TriStar 45 amp controller that can input 600 watts with a 150 Voc input allowing me to connect the panels in series and not have all that incompatibility. That is what I would have done because I know what I am doing. No compromises needed.

It's pretty amazing, but this is more misinformation. The Morningstar TriStar 45 amp charge controller is a lot more than $150 more than the Tracer. The best price on the Morningstar I could find when I bought my controller was around $480, and I see it's now come down a bit to $420. Plus an additional $140 for the remote monitor, which is important for my setup. That's a total of $620 for the Morningstar. My controller was $165 plus $35 for the remote monitor, for a total of $200. If it was only $150 more for the Morningstar I probably would have bought it, but $420 more (over 3x the cost) put it in a different category, especially since the Tracer was well reviewed and fine for my specs (and in all likelihood will continue to be).

And just curious: if your solar array expanded beyond the capacity of the Morningstar that you magically purchased for less than 1/2 of its actual cost, would you then "not know what you're doing", because your plans changed?

And good lord I can't believe I have to repeat this yet again, but:

I cannot wire my panels in series because of shade issues.

Which necessitates a compromise. And it also means I haven't outgrown my charge controller in the first place. Even if I was wiring two of the panels together in series I wouldn't be, but that's beside the point. I'm adding one, maybe two panels to a single panel 300 watt system that's been working beautifully for coming on a year. I didn't expect to want to power the fridge off of it part time, or to have two panels basically given to me. But even so, the controller I purchased had plenty of headroom for exactly this sort of unexpected need, and I haven't outgrown it yet. And even if I do, it would hardly mean that "I don't know what I'm doing", it would just mean that it's time for an upgrade, which I fully knew was a possibility when I bought it. Compromises.

It's one thing to be an internet blowhard, but don't just make stuff up or mischaracterize people's statements to win arguments. And wow do you get into a lot of arguments, here and elsewhere. You obviously have a lot of knowledge that's useful to the solar community, but good lord is it obfuscated.

[Sunking]

I cannot wire my panels in series because of shade issues.

Now that is some funny stuff I do not care who you are. Why would anyone park an RV in the shade if they use solar for power.

You are also a horrible shopper as you can get the MS 45 MPPT for less than $350

[Wrybread]

I don't park my RV in the shade, but I do store surfboards on the roof of my camper that occasionally cover part of one of the panels.

And as far as the charge controller, that is indeed a good price and I bow before the god of shopping. That's oddly cheap and doesn't show up in a google search or on google shopping, typically it's more like this or this or this. But it's still more than twice the price of a unit that has served me perfectly well, and that's before adding an additional $140 for the remote monitor, which is important for my setup.

EDIT: the price at that link has been fixed, and is now $478.

[Wrybread]

Well that's interesting, I called the folks at the link Sunking posted for the Morningstar TS-MPPT-45 asking why their price is a good $100 cheaper than everyone else since I figured it must be grey market, and they said that they'll be increasing it by the end of the week to match Morningstar's MAP ("minimum advertized pricing") policy. So if you're in the market for that charge controller, you might want to grab it from that link asap! Or maybe they'll honor that price ($336) in the future if you ask.

As far as the update on my project, I connected a Raspberry Pi to my controller using the cable method here and wrote a little Python script that switches my fridge over to AC power whenever the battery's SOC is above 85% and the charge controller is putting out more than 300 watts. I'm not sure how the Tracer computes the SOC, but it doesn't seem to be only based on voltage, and so far its been a useful metric for determining when the batteries are charged well enough to power the fridge. I might change the threshholds of course, but so far so good, and at the end of the day I get a few hours of solar fridge time and fully charged batteries. I've only tested for a few days so far though, and I'm not yet logging how much time per day I'm getting of AC fridge.

My fridge (standard RV style Dometic) pulls around 280 watts when on AC, so I'd prefer not to power off batteries unless they're actively getting charged. Incidentally this is a very easy thing to do with any fridge that has an "auto" mode, since when they receive AC power they'll use it, and when the AC power is removed they kick back over to propane. So all the Pi or whatever simply needs to trip a relay when the threshhold is met.

From there it was easy to make a little app so I can monitor my panel remotely. Here's a screenshot of what it looks like in the morning with the sun coming up. The value in the center and on the graph is wattage. I plan to add the rest of the relevant data from the charge controller (pv voltage, pv amperage, battery SOC - to whatever extent that's useful) and the temperature inside the fridge and its power source at some point. IMG_2113.PNG


Some of the other values given by the charge controller over the modbus interface are kind of interesting too, like maximum pv voltage today, generated energy today / this month / this year / ever. The full list of parameters is here if anyone else needs them.

I need to watch how things work over the course of a couple of weeks, since obviously I don't want to use this system if it means my batteries aren't getting charged, but that should be solvable by adding the third panel or changing the threshholds.

[ewarnerusa]

Fancy schmancy, Wrybread. I tried googling Raspberry Pi and don't exactly have it figured out. But it looks like some type of controller for turning USB ports on and off based on a user program? Anyway, if you're monitoring things by computer then you can hook up a Morningstar Tristar to a PC as well and use the MSVIEW software to access/monitor everything the $100+ remote panel offers. I suspect much more actually, but I don't have the remote panel with my Tristar (PWM 45) to compare. MSVIEW makes programming and monitoring the Tristar very easy. I have geeked out over program setpoints plenty of times and monitored things closely with the laptop running MSVIEW, but now I just look at my digital voltmeter to know what charge stage things are in to have a feel for what is going on. Bottom line, we don't run out of battery power while camping and (for us) no need to know any more details. Who says solar doesn't work for off grid camping, right?

[Wrybread]

Sorry I should have said, a Raspberry Pi is a little computer about the size of a deck of cards. It draws very little power (2 to 4 watts) so I can leave it running 24/7 without much impact, and it runs the Linux operating system so there's almost never a need to reboot it. Super reliable and configurable. I like to say its like a blender or any other appliance, it just does its thing super reliably. I'm running it "headless", meaning no monitor or keyboard attached (I configure it over the network), but I could connect a monitor to it to display data. But viewing the data on my phone is more convenient for me, and I leave an old phone stuck to the fridge permanently displaying the data.

The Tracer has some stock software to monitor and configure it from a laptop as well, and I've found it useful for seeing longterm data, but I don't use it much for seeing current conditions since it's a bit unwieldy to connect a laptop every time. Besides it doesn't give me the flexibility of doing things with the data, like automatically triggering a relay when X conditions are met. And of course laptops take too much power to leave running 24/7 just for this type of application.

As far as monitoring the voltage of your batteries, if you ever want something more permanent Amazon sells a battery monitor that's pretty well reviewed for under $20. I've always wanted to try it:

https://www.amazon.com/bayite-6-5-10.../dp/B013PKYILS

I have the Trimetric so I don't really have a need, but it's so well reviewed that I'm tempted to get one just to play with.

> Who says solar doesn't work for off grid camping, right?

Hopefully no one? Or people who haven't actually tried it? It works fantastically well!

[ewarnerusa]

I have seen that monitor referenced on RV.net and follow a thread about it. I do have an Amazon-purchased digital voltmeter that I installed in the wall with an on/off switch. It isn't reading directly at the batteries so I'm seeing all kinds of bias but it serves its purpose. At least it has a potentiometer so I can calibrate it.

In hindsight, I suppose MSVIEW wouldn't offer you a way to trigger relays based on performance. But that is way out of my league anyway. It does offer .csv file logging of parameters, so maybe that can be used to trigger something.

[Wrybread]

The main problem with using a laptop for 24/7 monitoring in an off-grid application is that the power draw is pretty massive compared to gizmos like the Raspberry Pi. There's also space issues, and longterm reliability issues since there's moving parts (fans and harddrives). Also from a quick Google search it looks like MSVIEW is Windows only, so it's not ideal if longterm reliability is critical.

I should also mention that the method I'm using would work with a Morningstar too, since they output their data the same way as the Tracers (via ModBus).

[ewarnerusa]

Agreed, the laptop consumes a lot of power to have plugged in all day. I have tried to work around that by using a 12V adapter to cut out any inverter use, having the laptop display off unless needed, and also put a 12V outlet timer on with a schedule built around solar harvest. So I can keep the laptop running all night and day if the sun cooperates, but it doesn't address the issue of using so much harvest just to keep the laptop running. It frustrates me that I have this Microsoft tablet from a few years ago that won't run the MSVIEW software! The tablet would use less energy than the laptop. But this only becomes an issue when I'm in one of my tinkering moods, usually the setup is left alone to do its thing.

[Wrybread]

It's too bad Morningstar hasn't put their remote montoring features on their lower end charge controllers yet. On their MPPT-60 you can plug the controller directly into a network and monitor the settings from any gizmo attached to your network, or (if desired) over the internet. Note the method this guy is using for example:

https://www.youtube.com/watch?v=X2XBguHAK_w

As far as I know that feature isn't available on any other models though. There's conflicting info about that though, since this Amazon listing for the MPPT-45a says it has the ethernet port, but according to the reviews it doesn't. I don't know, and it wouldn't solve my needs anyway, since I want to use the power from my panels for something else once the batteries are fully charged.

[ewarnerusa]

Yeah, my Tristar PWM 45 interfaces with a RS232 cable. I need to use a USB converter with it!

[Wrybread]

And looking at more product pages, it looks like they might have added the webserver feature to the MPPT-45a? It's certainly commonly mentioned on the features list. The product listing that Sunking posted says it has "Ethernet: fully web-enabled interface to a local network or internet; view from a web browser orsend email/text messages" for example. But people in the Amazon reviews specifically say it doesn't have that feature. Dunno, maybe newer models do?