Home solar panel on RV...anyone attempted?

[TobyG]

Okay, I have one extra solar panel from my home system. The panel is 66.5" x 40" in size see the specs below. I have looked online and haven't been able to find many people who have done this. Am I missing something? I have only a basic knowledge of solar but, on the surface it seems like it should work with the right sized controller. My thought is if I can mount one large panel vs. several smaller panels it would just simplify installation. So, my questions are:
1. can I use the home panel on my Trailer?
2. what controller?
3. where to mount on the roof?

With regard to that last quetion. My 1st choice would be near the front (see arrow) for making the wiring easier as well as less things in the way to possibly shade the panel. Main concern is the excessive wind at the front. Which brings me the the question of how to mount and have the option of tilting the panel?
Other mounting options would be near the back (see other two arrow) However mounting back there would bring possible shading issues into play.

Thoughts??? Idea?

[lawrosa]

Yes thats the charge controller. Works great with my twp panels in series. 560 watts and about 70 volts in.

Ill have a better idea come camping season as I have just been doing driveway tests.

Ep ever discontinued that model. I dont know why. This is the new model.

https://www.amazon.com/gp/product/B077HQPV1Y/ref=s9_acsd_hps_bw_c_x_6_w

[TobyG]

lawrosa wrote:
Dont know why it wasnt posted, or maybe I missed it on my re-read... What batterys do you have?

Your 1000 watt inverter may be set for crazy alarm voltages. My krieger inverter is a 10 volt cut off with a 10.5 volt alarm.

You do realize when you runn a 1000 watt load from the inverter you are drawing 90 amps from the batterys?

Standby losses are about .5 amps.

Now you think a 3000 watt inverter will fix it? Nope. It will be worse. Technically if you tried to draw 3000 watts thats 250 amps... Ha ha ha.. LOL.

Let us know the batts you have.

Maybe its

1. you have 6 volts and they have higher resistance why the voltage drop.
2. The inverter has a high alarm value like 11.5 or something. ( post actual models.
3. You dont have enough battery and/or wire is so small you have too much voltage drop

What to do>

1. Make coffee in a stove top percolator.
2. Warm food the old fashioned way. Pots, pans, oven,
3. Forget the microwave. Buy jiffy pop. Warm coffee on the stove..

12v offers lower resistance possibly. I have not proven this yet. But I still use 12 volters.

Watch this video. Sorry I mumble

https://www.youtube.com/watch?v=wz2ttT8fFLc

And this draw test with toaster over..

https://www.youtube.com/watch?v=7p-oNT8YDIs&t=1351s

Thanks for the info. I currently have an old XPower by Xantrax 1000 inverter connected to two 6v golf cart batteries with 220ah. However, after further investigation I have figured out that my wire might be the culprit. I thought I had wired it with 2awg but, in reality it was 4awg wire. I plan to replace the old 1000watt inverter as the new one has a remote switch and it was really too good of a deal to pass up. I know it will drain the batteries faster but, other than the coffee maker we really use very little power on a regular basis.
In the 1st video I noticed your charge controller. By chance is This the controller you have? If so, how has it worked for you?

[Boon_Docker]

Using AWG 6 is a good idea, then the voltage drop will be only 0.095 V.

I have been using this inline circuit breaker for 7 years now between the panels and controller, works great.

[Boon_Docker]

..

[TobyG]

Boon Docker wrote:
I would go with with minimum 8 AWG for the run from the controller to the batteries.

Six foot run at 13 volts / 20 amps.
Loss with 12 AWG = 0.38 volts (way too much voltage drop)
Loss with 8 AWG = 0.15 volts (still a bit high)

I appreciate the info. I was thinking 6awg from the controller to the batteries. However the run from the batteries to the 3k inverter is another story. The inverter came with 0AWG wire but, it's only 15" which is about 4' short. What I was thinking was to use the provided 15" 0AWG wire to a 400A waterproof breaker mounted to the tongue of the trailer, then continue to the inverter with more 0AWG wire.
Final piece of the puzzle what size breaker should be used between the panel and the controller. I haven't settled on which controller but, I do know it will be 35A or 40A based on what's needed.(335w panel to 2x 6v battery bank) The reason for a breaker is to give me a simple way to disconnect the panel if any work needs to be done. It's not something I intend to use regularly.Thoughts and or suggestions?

[lawrosa]

Dont know why it wasnt posted, or maybe I missed it on my re-read... What batterys do you have?

Your 1000 watt inverter may be set for crazy alarm voltages. My krieger inverter is a 10 volt cut off with a 10.5 volt alarm.

You do realize when you runn a 1000 watt load from the inverter you are drawing 90 amps from the batterys?

Standby losses are about .5 amps.

Now you think a 3000 watt inverter will fix it? Nope. It will be worse. Technically if you tried to draw 3000 watts thats 250 amps... Ha ha ha.. LOL.

Let us know the batts you have.

Maybe its

1. you have 6 volts and they have higher resistance why the voltage drop.
2. The inverter has a high alarm value like 11.5 or something. ( post actual models.
3. You dont have enough battery and/or wire is so small you have too much voltage drop

What to do>

1. Make coffee in a stove top percolator.
2. Warm food the old fashioned way. Pots, pans, oven,
3. Forget the microwave. Buy jiffy pop. Warm coffee on the stove..

12v offers lower resistance possibly. I have not proven this yet. But I still use 12 volters.

Watch this video. Sorry I mumble

https://www.youtube.com/watch?v=wz2ttT8fFLc

And this draw test with toaster over..

https://www.youtube.com/watch?v=7p-oNT8YDIs&t=1351s

[Boon_Docker]

I would go with with minimum 8 AWG for the run from the controller to the batteries.

Six foot run at 13 volts / 20 amps.
Loss with 12 AWG = 0.38 volts (way too much voltage drop)
Loss with 8 AWG = 0.15 volts (still a bit high)

[TobyG]

TobyG wrote:

Boon Docker wrote:
TobyG, what is the distance between the panel and the charge controller and what distance between the controller and the batteries?

both runs will be 5-6' max.

scratch that, I miss-read the 1st time. The run from the panel to controller is less than 10'. I'd say closer to 8'based on where I think I can run the cable. The run between the controller and the batteries is 5-6'.

[TobyG]

westend wrote:
You don't state the size of the inverter and that will dictate your highest current draw and your largest cable size. Most inverters have wire sizes applicable to the current. Your panel won't develop more than about 20 amp charge current so the smallest sized wire from controller to battery would be 12 AWG. 36V and maximium current from the panel would indicate 12 AWG also to be adequate.

FWIW, since I decided to have the least loss of harvest possible and had to order 100' of 4 AWG, I decided to use it for most of my runs. I bought the cable at Waytek Wire, they are local to me. A good online seller that will make custom wire pieces is Genuinedealz.com.

Here is a wire gauge calculator: Calculator

Thanks! I will check out that site for wire. I currently have a 1000watt inverter (modified sine) but, I just came across a great "open-box" deal on a 3000watt inverter with a remote on/off switch also mod-sine. What I found with the 1000w is it didn't like the load my coffee maker put on it and keep beeping at me even though the coffee maker was only 900w. The new 3k inverter states to use 00awg wire and a 500-amp ANL fuse if hard wired. Does this sound like overkill?

[TobyG]

Boon Docker wrote:
TobyG, what is the distance between the panel and the charge controller and what distance between the controller and the batteries?

both runs will be 5-6' max.

[Boon_Docker]

TobyG, what is the distance between the panel and the charge controller and what distance between the controller and the batteries?

[westend]

You don't state the size of the inverter and that will dictate your highest current draw and your largest cable size. Most inverters have wire sizes applicable to the current. Your panel won't develop more than about 20 amp charge current so the smallest sized wire from controller to battery would be 12 AWG. 36V and maximium current from the panel would indicate 12 AWG also to be adequate.

FWIW, since I decided to have the least loss of harvest possible and had to order 100' of 4 AWG, I decided to use it for most of my runs. I bought the cable at Waytek Wire, they are local to me. A good online seller that will make custom wire pieces is Genuinedealz.com.

Here is a wire gauge calculator: Calculator

[TobyG]

lawrosa wrote:

TobyG wrote:
Thanks for the suggestions on equipment and just for the record I'm aware that there is no such thing as a "home panels and RV panels" I was merely trying to paint a visual for people. The panel I have is an: LG335N1C-A5 Since I can't get my pictures to work the specs on the panel are:
Vmp 34.10 V
Imp 9.83 A
Voc 41.00 V
Isc 10.49 A
Pmax 335 watt

I am only using one panel. I'm trying to decide on MPPT controllers. Currently I am looking at the
Epever 40A MPPT
or the
EpicSolar 40A MPPT
but, I am open to hear other suggestions.
I also, need to look at switchable fuses, bussbar, wire and some other incidentals. Does anyone have suggestions on what would be a good fit for my size system?

The two controllers you linked are the same controllers... Watch where you order from. The solar epic comes from hong kong.. The epever sold by ZHC can be fulfilled by amazon...

Thanks, any suggestions on wire or fuses and where to get a good price? My run from the batteries to the controller and inverter are 5-6'. The solar panels to the controller is less than 10 feet.

[westend]

I will list my gear here since where you are headed is fairly similar. I'll leave some comments, also.

Module = 235W USA built panel (no longer being mfg) 36V Vmp, 7.5 A Imp, Pmax 235W
Controller = Morningstar MPPT-15 with MS software included. I wouldn't buy a controller without robust software, it makes allocating settings very easy and you can observe in real time what the harvest is.
Circuit protection = Bussman 25 A manual breaker between panel and controller.
Bus bars = I built my own out of 4" plastic boxes and copper bars. The bars are tapped to accomodate 1/4" SAE threads.
Wire = I have a roof top junction box with two connection terminal strips, again, built from hardware I had and a few store-bought items. It will allow me to expand system with another parallel loaded module. MC4 12 ga from the panel to the box. 4AWG cable is used for everything downstream and to bus bars/batteries.

I have two battery banks, at present, with 300AH of capacity. There is a bus bar for each battery bank (+) phase and a common (-) phase bus. I made a distribution panel that controls current to/from both battery banks to charge controller, converter, and inverter. I wanted the flexibility to draw or charge to either bank.

Bus bars:


Distribution panel:

The paper cutout is where the inverter is located.