First 220RK Solar / Lithium install

[DaveMatthewsBand]

Edit

Sent from my iPhone using Tapatalk

[DaveMatthewsBand]

Our Progressive Industries EMS tripped during the night with an E3 high-voltage error (over 132 volts) and cut off power to our rig, so we were down to 90% this morning.

This gave me the opportunity to record the charge rate from 90 to 99%.
Watching the batteries charge past 90% was very educational.
You can see the charging amps decreasing as the DoD gets closer to 100%.
And at 98% the charging rate goes through a range of 4 rates, successively smaller, same thing when they hit 99%.
It was interesting that it took about 20 minutes to go from 90% DoD to 98%, but since the charging amperage had dropped so low by that point, that last 2% took about 20 additional minutes.
Videos are huge, and get pixelated by Youtube, so I created a slideshow from photos and uploaded it to YouTube.

LINK

[howson]

The big thing for us, is a solar set up like this gives you choices.

Our rig was built to boondock away from the crowds, and close to beautiful scenic places. We’re currently exploring the Washington coast, and there’s not as many options so the most convenient places to stay are the Thousand Trails RV parks that line the coast, but they’re crowded, the rigs are jammed in so close together they can’t open their awnings, most have slides within a couple feet of each other.

But since we have this solar set up we have the option to camp out in the overflow area, which is just a big field, away from the crowd, yet we are still within walking distance of the beach. We fill up our fresh and dump tanks about every 8-10 days, rinse and repeat. This is one of many reasons the cost of lithium is worth it!

Here’s a couple photos showing our location outside the sardine can.

This is the most compelling post I've seen for an independent power setup in/on the RV. I'd love to be able to do what DMB is doing in these pictures! (I'm reviewing old threads doing research on inverters and stumbled across this post.)

[DaveMatthewsBand]

Thanks
Sardines are icky


Sent from my iPhone using Tapatalk

[DaveMatthewsBand]

My three panels are wired in series, and even when one of them is fully shaded, it still allows the current from the other two to pass through. I've often heard that if one of your panels gets shaded, that you would not get any charging. So at last year's Quartzsite rally, we ran an experiment. I have three panels, and measured the voltage and current. Then, we completely covered one of the panels with cardboard and tape so that no sunlight was getting to it. The current remained the same, and the voltage was reduced by 1/3. In the early days of solar, if you obscured one panel in a series configuration, you'd lose the whole circuit. Most panels sold today have pass through technology to prevent that.

There is a lot of benefit to running a series configuration. One being that you can use a smaller gauge wire to carry the current generated in that configuration. If you run in parallel, the voltage remains the same, and the current increases. This can force you into using larger gauge wire to handle the current.

Jim

Curious to hear your thoughts on this video Jim, since my panels are wired in parallel and your opinion is that series is the better method.

https://youtu.be/Z1ur3kSHuBU



Sent from my iPhone using Tapatalk

[BigSwick]

You know, after full-timing for 2 months now we are still blown away by how quickly these batteries charge back up! Even on cloudy days.
We have gotten spoiled being able to use the microwave, TV and everything else way past sunset, we’re usually up till midnight or 1am, only to have our batteries at 100% charge well before noon every single day, then of course during the day we can’t get them below 98% if we try.
They’re like tiny 0 decibel generators.

The big thing for us, is a solar set up like this gives you choices.

Our rig was built to boondock away from the crowds, and close to beautiful scenic places. We’re currently exploring the Washington coast, and there’s not as many options so the most convenient places to stay are the Thousand Trails RV parks that line the coast, but they’re crowded, the rigs are jammed in so close together they can’t open their awnings, most have slides within a couple feet of each other.

But since we have this solar set up we have the option to camp out in the overflow area, which is just a big field, away from the crowd, yet we are still within walking distance of the beach. We fill up our fresh and dump tanks about every 8-10 days, rinse and repeat. This is one of many reasons the cost of lithium is worth it!

Here’s a couple photos showing our location outside the sardine can.













Sent from my iPhone using Tapatalk

Dave, very nice setup. After seeing it all in place, do you think it could be installed as a DIY project?
And when you see say you dump and fill every eight days or so- I am curious- I have never seen a campground that has a water spigot for potable water seperate from the dump station. (But I am in Florida). I assume you don't use the dump station water, so how do you fill?

[DaveMatthewsBand]

Dave, very nice setup. After seeing it all in place, do you think it could be installed as a DIY project?
And when you see say you dump and fill every eight days or so- I am curious- I have never seen a campground that has a water spigot for potable water seperate from the dump station. (But I am in Florida). I assume you don't use the dump station water, so how do you fill?

Thanks...

There are several members here that have installed large solar setups as a DIY project. Do a search and you’ll find several threads on this.
However I wanted my install to be done by a professional, particularly one with a good reputation and many years of experience in the field.

To answer your water hose question...
I’ve never camped in Florida, but most places on the West coast have a separate hose in another location for the fresh tank.
That’s what we use. Also any water we take onboard goes through our large water filter and water softener before entering the fresh water tank. We also run our drinking water through a Berkey tabletop water filter, which is arguably the best money can buy and can filter lake water into safe drinking water if need be.

[TucsonJim]

Curious to hear your thoughts on this video Jim, since my panels are wired in parallel and your opinion is that series is the better method.

https://youtu.be/Z1ur3kSHuBU



Sent from my iPhone using Tapatalk

Hi Ed - The gentleman in the the video does a great job of explaining the two different types of connecting methods. He explains the pro's and con's of each method.

On older solar panels, partial shading was a big draw back in a series connected set up. The partial shade would shut down the whole circuit. But as he mentions in the video, this has now been overcome by using bypass diodes in the panel. Bypass diodes will shunt around the shaded panel and still allow current to flow from the unshaded areas. When I built my system, I demonstrated this by completely blocking out one of my panels. But I still had current and voltage from the remaining panels because the bypass diodes allowed the current to flow. A good analogy would be the old fashioned Christmas lights. If one bulb failed, the entire string would go out. But most manufacturers not have a third wire in these strings which allows current to flow if one bulb goes out.

The main drawback for parallel operations is the size of the wire that is needed from the panel array to the controller. The video does a good job of discussing this. In DC circuits, you can encounter a lot of line loss. The more current you have, the larger the wire you need to combat the line loss. Let's take the panels that he was using as an example:

Using four panels, he had a Vpp of 18V, and a current of 5.5 amps. Let's also assume that the run from the cables to the controller is 25 feet.

In series, you'd have 72 volts and 5.5 amps. For a 2% line loss, you'd need to use a minimum wire size of 14 AWG.
In parallel, you'd have 18 volts and 22 amps. For a 2% line loss, you'd need to use a minimum wire size of 8 AWG.

In addition, when using parallel, you typically have more complicated wiring because you'll either need a combiner box or combiner connections.

In short, either method will work fine and provide the end result of charging the batteries. Here are the pros and cons:

Series Pros - Smaller wire sizes required, easier wiring configuration
Series Cons - Must use bypass diodes or run risk of system shut down in shade.

Parallel Pros - Shading does not affect system, so bypass diodes are not required.
Parallel Cons - Combiner box or connections are required. Larger wire sizes are needed between the panels and the controller to handle the current.

Jim

[DaveMatthewsBand]

Thanks for your input Jim, its always good to hear advice from a professional!
Being a novice, I’m unclear on why thicker cabling is a con. Is this just due to the cost?
To be honest I left it up to Brian as to which method to use for wiring the panels.
He recommended parallel, but he also mentioned the cables would cost twice as much.
But after I spent almost $4k on batteries and $2k on an inverter, the extra money for thicker cables didn’t really phase me.

8 )


Sent from my iPhone using Tapatalk

[gosupes]

I have to say this is a great thread for those of us looking into extensive traveling in the future. Our family has an off grid cabin and you have given me some good info to mull over.