Any tips on my setup?

[-TX-]

Not really. I had a contract about 6 months ago where I saw an advantage in off-grid and went from there. It's been an experience!

12x230ah, 4S3P. I should create a post of where I'm at. lot of work.

[Wrybread]

In fact here's the view as I type this from my RV:

[-TX-]

Tabs have given me a headache

[Wrybread]

> Tabs have given me a headache

Ha! Amen.

Are you using any kind of battery monitor on your system?

[SunEagle]

You just agreed with my comment about the tech being immature.

The tech concerning "tracking" has improved to the point that there are more and more Utility sized solar arrays that have found a way to install their panels with at least a single axis tracker that is cost effective by producing more then the cost of maintaining the mechanical side.

For the home user a tracker is not yet economical but due to the cost of solar panels dropping it is better to just install more panels at different fixed compass points to increase the yield.

[SunEagle]

In fact here's the view as I type this from my RV:

I am not trying to get personal but it looks a little cramped.

While I am close to retirement and my wife would enjoy living (for short times) in our 36ft Class A RV it would not be something I would chose to have raised our kids in. But then again there are some people that seem to like those "little houses" that you tow around behind a truck.

To each their own if you enjoy the life style then I can't fault you on your choice.

[-TX-]

> Tabs have given me a headache

Ha! Amen.

Are you using any kind of battery monitor on your system?

Not specifically, no. But I do have my inverter (and soon) controller monitoring them (mppt will also have a temp gauge), and a couple of voltmeters so I can steal an easy glance at their status constantly.

I'll need a better solution though because my inverter is hard set to issue an alarm only when voltage drops under 21v, and at 21v the things are massively depleted. I don't know what the manufacturers point was to set it so low. Deka, for example, says that their battery is 50% depleted at 24.4v. That's where an alarm should ring.

[-TX-]

I am not trying to get personal but it looks a little cramped.

While I am close to retirement and my wife would enjoy living (for short times) in our 36ft Class A RV it would not be something I would chose to have raised our kids in. But then again there are some people that seem to like those "little houses" that you tow around behind a truck.

To each their own if you enjoy the life style then I can't fault you on your choice.

Beats $100/night hotels every day and twice on Sundays!

20170309_090039_001.jpg

[Sunking]

2k, awesome! What are you doing for a battery bank?

That indeed is a massive system and I'd go 24 volt for that too.

I agree with some things Sunking said about MPPT. Don't get me wrong, I'm not advocating PWM. Where I disagree with him is a) that the Tracer 4210A controller is a POS (I don't think he's updated his thinking since the early Chinese "MPPT" controllers on ebay that were fakes; these are very well reviewed), and b) that its inadequate for my setup to the point that it justifies spending another $600+..

You are hard headed and not listening.

While at 2000 watts, 24 volts is a poor choice and too expensive. That would require an 80 amp controller and no room to grow. Not having room to grow is not a deal breaker, but a simple change to 48 volts only requires a much less expensive 40 amp controller. Not only a lot os savings in controller cost, but also trickles down to lower wiring cost.

The Tracer is a fair entry level controller if it is matched and made to work with your equipment. That is where you went off track as the Tracer is not compatible with your panels. It will not allow you to wire your panels in series so you can take full advantage of MPPT and utilize all the power available. Why is that so hard for you to understand?

I believe you have 20 years of experience, not from your knowledge as it is severely lacking and way out of date. Your approach is that of 20 years ago when you had to make compromises and you are stuck in antiquated methods. 20 years ago there were no high voltage solar panels, MPPT Controllers or near the amount of batteries available today tailored to RE use. If I had to guess you are a mechanic and work on RV's and have not kept up. Today there is absolutely no reason you have to make any compromises in RV application. There is no need to wire panels and batteries in parallel, or over power a controller to gain a few more AH. That is a waste of money and resources. You could have achieved the same thing for less money by simply matching th equipment up to work with each other. 20 years ago when you started you had to make compromises, not today. You are stuck in the past.

Anyway I really do not care what you do, it is your money and life you are wasting away. But I nor the management of this forum are going to allow you to give bad advice. You will not get away with it here. It is not personal, just facts. If you want to quit learning fine with me. Just do not be giving anyone any advice.

[SunEagle]

Beats $100/night hotels every day and twice on Sundays!

20170309_090039_001.jpg

Nice. Looks comfortable to me.

[Sunking]

Beats $100/night hotels every day and twice on Sundays!

20170309_090039_001.jpg

Yes looks nice. But you are going to need a lot more than a 250 watt solar system.

[sensij]

One factor to consider when evaluating whether or not to put panels in series, which isn't directly applicable to the OP's situation but may still be worth discussing here, is the impact on the charge controller's efficiency as panel voltage gets further away from battery voltage. For example, the Tracer's manual provides the following chart, showing how panels in series would perform in a 12 V system (despite Sunking's insistence that this configuration is not possible on this controller). You can see that putting two 34 Vmp panels in series would drop the efficiency at full load from 95% to just under 94%, according to this chart. Depending on the length of the run from the panels to the CC, and the size and cost of wire and terminations selected, the system could in fact be more cost-effective / efficient with the panels in parallel. The extra cost from fusing when exceeding two panels in parallel is another difference to be aware of, though.
TracerEfficiency.JPG

[Sunking]

One factor to consider when evaluating whether or not to put panels in series, which isn't directly applicable to the OP's situation but may still be worth discussing here, is the impact on the charge controller's efficiency as panel voltage gets further away from battery voltage. For example, the Tracer's manual provides the following chart, showing how panels in series would perform in a 12 V system (despite Sunking's insistence that this configuration is not possible on this controller). You can see that putting two 34 Vmp panels in series would drop the efficiency at full load from 95% to just under 94%,

You do not use VMP voltages, you use Voc. A 34 Vmp panel Voc is 48 volts on a 92 VOC or even a 100 Voc New Zealand model controller will not work. Not hard to comprehend.

You are also arguing a 1% loss difference. The saving in cost on wiring and material is worth 1% loss difference.

Your argument is a moot point and not valid.

[sensij]

You do not use VMP voltages, you use Voc. A 34 Vmp panel Voc is 48 volts on a 92 VOC or even a 100 Voc New Zealand model controller will not work. Not hard to comprehend.

You are also arguing a 1% loss difference. The saving in cost on wiring and material is worth 1% loss difference.

Your argument is a moot point and not valid.

You absolutely use Vmp when evaluating operating efficiency and transmission loss. Voc only matters relative to the charge controller's specification, and as we've already established, two 24 V panels in series is fine on this controller in locations that don't get too cold. Surely you are familiar with 2014 NEC 690.7(A).

NEC.JPG

[Wrybread]

@Suneagle: Ha good point. That's a pretty bad picture of it though. Its perfect for my girlfriend and I: 2 offices (one in the back with awesome panorama views of the beach usually) and another table in the middle, and we sleep in the roomy bed above the cab. Its a 24 foot Class C. For my girlfriend and I I'd call it just right. My previous camper was a Hitchhiker III 5th Wheel very much like TX's, and personally I'm glad for the downsize, but those are because of personal factors like driving on winding Route 1 in California from time to time (not fun in a 5th Wheel!), and slideouts when parked on the beach become a maintenance hassle. My trailer after that was a 45 foot 1956 Spartan. Now *that* was an awesome trailer!

As far as Sunking's new misinterpretations of my needs and statements, I'll just say that I certainly wasn't suggesting that 250 watts would be enough for TX's trailer. Personally I'd go 600 watts of solar (or 900 if you want to go nuts) and a 2000 watt Honda EU for emergencies and call it a day (and try to keep some headroom so you can expand in the unlikely event you find you need to), but I know that diverges from the Platonic ideal of solar systems. But if you don't realize that the way I'm suggesting is the standard high-end way of outfitting RVs, and furthermore that it works awesomely (and is in fact overkill), then you don't have enough experience with the topic at hand (solar for RVs). Ok fine, the Honda EU is cutting corners, but personally I think its an improvement over most RV gennies.

And it's absolutely mind boggling that he still doesn't understand that I'm adding panels to an existing system, so keeping my existing controller, especially when it will very likely work just fine, is, at a minimum, the best way to start. It's also mind boggling that he really feels the need to rant about my controller in like 20 posts. This statement is also pretty amazing for its sheer lack of understanding:

Today there is absolutely no reason you have to make any compromises in RV application.

It's hard to believe that that's a serious statement. Just to name a few reasons to compromise in an RV solar install:

- price! (usually the biggie) I don't know what parallel universe Sunking is living in where price isn't a factor, but most people don't spend $600 (or $10,000) lightly. Cost/benefit analysis.

- space (also a massive factor with RVs)

- and the number one reason: the fact that with modern panels and controllers you can get all the power you need without getting the absolute best (and most expensive) of everything. That's not to say we shouldn't, in my opinion, aim for maximum efficiency, but as with everything you have to assess the costs and benefits.

And there's a bunch of miscellany like using your equipment at hand when possible, simplicity (within reason) and shade issues.

There is no need to wire panels and batteries in parallel,

Unless, as I explained a bunch of times, you have shade issues! And unless you already have a controller that will probably work just fine with the panels in parallel, so you don't see the need to spend an additional $600 just because some internet blowhard is oddly desperate to get his point across.

I'm seriously questioning his motivations at this point.