eric1514
Senior Member
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- Mar 14, 2014
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No I'm not
That video was all brag. They didn't tell us what panels they chose and why or what controller they chose and why. I think it was a nice install, but educational?, no.
How Much Solar is Enough Solar?
- Thread starter BBQ-ClassB
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No I'm not
That video was all brag. They didn't tell us what panels they chose and why or what controller they chose and why. I think it was a nice install, but educational?, no.
WingedRyno
Senior Member
I think I see what you're saying. It's not that a panel is connected to a panel that is connected to a panel, but it's HOW it's connected to the panels that determines series vs parallel. It's a good point and their video could have been better on this part.
This getting to be way more weird than it needs to be. You are limited in series by the max voltages of the controller, and in parallel by the max current, in most cases. The illustration is correct, but you can also do series/parallel or parallel/series systems to get what you want for voltage and current. Just like with batteries.
BBQ-ClassB
Senior Member
Yes you can.
And this is where RT is amatures when it comes to connecting multi-panels.
The parallel side of the panels should be balanced (ie matched output),
otherwise your system will not be efficient in producing the optimal power.
markopolo-ClassB
Senior Member
.
How Much Solar is Enough Solar?
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120 watts on my van seems just about right. :thumbup:
100 watts on the travel trailer is more than needed but at around $250 for everything I don't think I wasted too much money.
The answer is - it depends on how much output you require.
My take away is they achieve 50-60 amps of charging with that 960w solar setup in its most optimistic circumstances. I can charge my batteries at an Idling rate of 220 amps any time night or rain with the second alternator. This is why it makes no sense to me to invest in solar.
They did recognize you have to tilt right angle at the sun to optimize. Winter especially but even in the summer flat on the roof is not optimum. Also in series you will have to choose your site carefully to optimize and avoid shade. I rarely boondock on BLM land in the dessert where you can orient you RV anyway possible and avoid shade. I did not see how you tilt the panels. If manual tilt instead of electric actuators, I'll pass.
They did recognize you have to tilt right angle at the sun to optimize. Winter especially but even in the summer flat on the roof is not optimum. Also in series you will have to choose your site carefully to optimize and avoid shade. I rarely boondock on BLM land in the dessert where you can orient you RV anyway possible and avoid shade. I did not see how you tilt the panels. If manual tilt instead of electric actuators, I'll pass.
BBQ-ClassB
Senior Member
WingedRyno
Senior Member
So RT wires them in series I'm assuming?
I might look at installing a DC optimizer to each panel to care of that issue. I think that will solve the shade issue perhaps beyond series vs parallel wiring and I think would work fine in either configuration.
To recharge an RV battery bank, we can use the following and they all make sense:
1. Engine primary alternator
2. Solar panels
3. Auxiliary generator
4. Shore power
5. Wind generator
6. Engine secondary alternator.
Each one of them have pluses and minuses which will vary with different scenarios but to make a statement that one of them makes no sense is rather arbitrary. I could say that a second alternator makes no sense just because it doesn’t for me but solar does. In case of Avanti I can see that the second alternator make sense because his primary alternator doesn’t charge his batteries. In your case when you tend drive a lot it makes sense as well, but for me it doesn’t, but it still make sense.
You are very proud of your Advanced RV but statistically they are the B-class market outlier in price and design, they don’t represent the main stream so coming from that corner and say that solar makes no sense is “interesting”.
I have 300W of solar with reasonable loads and the solar system for us was absolutely perfect in meeting our camping needs.
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Alternator charging works great for lithium chemistries.
It's rarely a good fit for lead acid chemistries because of the long, low-current absorption stage. For lead acid banks, alternator + some solar is nearly optimal. Alternator can quickly get you through bulk and early absorption then even small solar can handle later absorption and float.
Did I say anything factually wrong? The Wynn's said the could get 50-60 amps of there solar panels that obviously have to be tilted and oriented to the sun. That is possible in a dessert dispersed camping site with plenty of sun and then just peak hours. That's not the case just about anywhere outside of the Southwest. Plus, under rare circumstance can you get 960 watts of solar on a B and what you can get is often shaded by rooftop equipment and even the hiked up awning assembly on Sprinters. At best solar is a battery maintainer for storage for low amp battery banks. It is inefficient in cost benefit otherwise on a B, including the primary engine alternator that still outperforms solar. Avanti's primary engine alternator indeed charged the batteries at one time but he installed a more efficient second alternator as did Booster and both with AGM batteries.
The sun is unreliable to depend on most the the United States. To use it you limit yourself in camping sites. You can control, depend and predict your usage on a primary alternator, a secondary dual alternator or shore power.
"Reasonable loads" is a compromise phrase for conservation. I'm in to no worry, 24/7 use of my B with all electrical systems 120VAC outlets, microwave, coffee maker, curling iron, or any other electrical device always available without firing up a generator. You don't have that I guess so you have no concept of the freedom you enjoy having that. Just overnight in a Walmart parking lot and pine.
I've got 420 watts of solar panels in about the most efficient setup you can with individual MPPT controllers for each panel. I can measure the input accurately to the amp on my Silverleaf controller and I have the capability to set up a computer for more accurate monitoring information and I have come to my conclusions with factual information and not supposed, theoretical, or wished for information.
So, I am an outlier as your excuse to refute me. You are an outlier as well with you DIY B. What is bad about being an outlier in design. Advanced RV has had the benefit of a team to put together a B with the input of just about every customer to build on. They cost more because they are better at construction and their attention to detail both concealed and in sight. They generally have more than any other B just in regards to standard features. The customer gets exactly what they want from initial ordering of the van from M-B, to their own finishes, and custom features they bring to the table. I got exactly what I wanted including the electric articulating beds which I proposed and after 2-1/2 years I haven't added anything to my B except 3M Command Hooks and a beer bottle cap opener. I did voluntarily upgrade from the Nations dual alternator to the Delco-Remy. I didn't have to do it, it was just a desire and now I am one of the few who know the differences. I can afford it just as well as the 10 times greater retirees that buy half Million dollar Class A RVs. I just wanted that luxury in a B.
I would agree with the first statement, but only part of the second. With AGM, engine charging and solar does make a good combination and is the best choice if you are in the high ranges of SOC during your typical charging and use patterns. If you are running lower in the SOC range, which is very typical in the real world, of between 20% and 70%, you will have essentially no real difference in power recovery compared to lithium, with a moderate sized AGM bank (400ah). Both the lithium and AGM will take all the output the alternator will give, which is usually about 165ah per hour net in most engine generator systems. Of course, you would need to get a full charge on the AGMs every 7-10 cycles for max battery life.
So far the 440 watts of solar on my rig will supply enough perpetually for the fridge, lights,fans,and usb stuff. Thats if the sun comes out once in a while. If I use any of the 120v stuff, microwave, induction cook top,AC, etc... I will need extra power.
BBQ-ClassB
Senior Member
I took this statement from your previous post “This is why it makes no sense to me to invest in solar” as a generic recommendation which prompted me to reply. Perhaps I read too much into it. I have seen many satisfied folks with their solar installations, so I found your statement of “it makes no sense” not adding value to helping other folks trying to make a decision.
I brought Advanced RV in light of your reasoning to state that solar makes no sense, I often see you’re bringing your RV to justify a point, but that point is based on statistically small outlier population. There is nothing wrong in being in that small market corner population, but let’s be careful to generalize it to a broad base. I picked the alcohol stove, a real outlier in the RV world but very popular in the boating world, am I completely happy with it, no, I would prefer LPG and would recommend LPG.
That is a difference of a camping lifestyle, we camp in national forests, state and national parks, not once at Walmart.
Believe it or not I do have a concept of house comforts in US or EU, but going camping is different for us. We are not seeking an extension of these comforts, we camp.
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WingedRyno
Senior Member
You are a trove of wisdom.
BBQ-ClassB
Senior Member
LOL
We all learn... one way or the other. Some learn it by paying more.
How can it be amaturish when wiring panels in series?
If it is done wrong, it is ignorance, not amaturish.
There are more knowledge (and permutations) in wiring multi-panels than you assume.
:rock:
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BBQ-ClassB
Senior Member
Davydd said:
No, you read too little into it.
Davydd explained himself quite well when he said
“This is why it makes no sense to me to invest in solar”.
Where do you find this a "generic recommendation"?
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