Solar panel set up on 5th wheel

[Cmeister23]

Hi I’m getting ready to order my solar panels. Im looking for about 1200w and I think I will go with a 4 - 305w panels with the following specs :
60 cell mono

• Rated Power: 305W
• Open circuit voltage (VOC): 39.9 V
• Max power voltage (VMP): 32.3 V
• Short circuit current (ISC): 9.76 A
• Max power current: 9.45 A

Going to my 24v 280ah lifepo4 battery. I figure 2s2p connection to the scc. I used the victron calculator and they recommended the 150/45 mppt controller. Any insight I may be overlooking before I order would be appreciated!

 

[MisterSandals]

Sounds pretty reasonable with the info you've given.

Regarding "ordering panels" sounds expensive. Have you considered looking for big cheap panels on craigslist? You can often find panels at $.50 per watt. Maybe your source is as good or better. Or maybe you are determined to get those particular panels to fit your space. There are cheap options out there, if you give an zip code or city maybe someone can recommend a deal in your area.

 

[Cmeister23]

Thanks for your feedback! I've been searching daily for local panels and everyone in the Wash DC area must think they are selling gold. Many people are selling used panels for what I can buy new and have shipped (some are $1/w!) and I have to drive 1-1 1/2 hrs each way to get them. The best I found though locally is 260w @ $100 each and it says they haven't been used. That is probably the best way to go - I could do 6 panels and get 360 more watts. I'll probably end up spending about the same due to the costs of installing 2 more panels and the slightly more expensive 150/60 controller. I guess my hesitation is having to install 6 vs 4 panels but its probably not that much more work to get a 30% increase in power and there is no warranty on these panels. Is having a warranty at 1200w vs no warranty at 1560w something to worry about? Do panels go bad often? I guess with 6 panels I would do a 3s2p connection?

• Rated Power: 260W
• Open circuit voltage (VOC): 38.2 V
• Max power voltage (VMP): 30.6 V
• Short circuit current (ISC): 9.0 A
• Max power current: 8.5 A

 

[MisterSandals]

Is having a warranty at 1200w vs no warranty at 1560w something to worry about? Do panels go bad often? I guess with 6 panels I would do a 3s2p connection?

No, no, yes.

Test panels with volt meter if you can for peace of mind. Seller can likely show volts and amps.

 

[HRTKD]

I bought my panels from my local CEDGreenTech office. They were great to deal with. There is a location north of D.C. in Maryland.

I spent way too much time trying to find a reasonable price on panels that would be shipped. Finding local suppliers was difficult. It's like they didn't want to be found. After cancelling an order with one local retailer, I stumbled upon CEDGreenTech. I had to call them on the phone to get a price, but it was the best phone call I made for my PV/LiFePO4 upgrade project.

Fewer panels to install is how I would do it. My original plan was to use four 200 watt panels but I needed up with two 320 watt panels instead. There was no way to fit four panels on the roof of my RV trailer, but two larger panels fit just right.

 

[chrisski]

You really have a good plan.

The only thing I will recommend is getting a good plan to put those on the roof. Vents and AC and skylights make placement difficult. I have a 35’ fifth wheel and have half the roof filled up with 950 watts of panels. I left the driver’s side (roadside) of the RV open so I could walk across it. I could put another 950 up, probably more if I planned it better.

For your battery, that looks right sized to run high watt items for a few minutes. Perhaps warm your family’s food up at 2 minutes a person and not have to worry about excessive amps. You may be able to run a 1.7 l kettle fo boil water, and that will draw about 85 amps of power for 5 to six minutes. Does not look right sized to run A/C though, at least though the night.

 

[Cmeister23]

I bought my panels from my local CEDGreenTech office. They were great to deal with. There is a location north of D.C. in Maryland.

I spent way too much time trying to find a reasonable price on panels that would be shipped. Finding local suppliers was difficult. It's like they didn't want to be found. After cancelling an order with one local retailer, I stumbled upon CEDGreenTech. I had to call them on the phone to get a price, but it was the best phone call I made for my PV/LiFePO4 upgrade project.

Fewer panels to install is how I would do it. My original plan was to use four 200 watt panels but I needed up with two 320 watt panels instead. There was no way to fit four panels on the roof of my RV trailer, but two larger panels fit just right.

Thanks for the recommend on that! I just called the local office and they guy is putting together a quote for me. He is only like 20 minutes away too.

 

[Cmeister23]

You really have a good plan.

The only thing I will recommend is getting a good plan to put those on the roof. Vents and AC and skylights make placement difficult. I have a 35’ fifth wheel and have half the roof filled up with 950 watts of panels. I left the driver’s side (roadside) of the RV open so I could walk across it. I could put another 950 up, probably more if I planned it better.

For your battery, that looks right sized to run high watt items for a few minutes. Perhaps warm your family’s food up at 2 minutes a person and not have to worry about excessive amps. You may be able to run a 1.7 l kettle fo boil water, and that will draw about 85 amps of power for 5 to six minutes. Does not look right sized to run A/C though, at least though the night.

Thanks! Yes I have a cardboard cut out and it is close in some areas but looks like it will all fit.

 

[MisterSandals]

Thanks! Yes I have a cardboard cut out and it is close in some areas but looks like it will all fit.

Try to avoid things like tall vents and air conditioners that will create shade if possible.

 

[HRTKD]

Thanks! Yes I have a cardboard cut out and it is close in some areas but looks like it will all fit.

Keep in mind that if you use Z brackets to mount the solar panels, the brackets add about 1.5" to the long side of each panel.

 

[chrisski]

. I guess my hesitation is having to install 6 vs 4 panels but its probably not that much more work to get a 30% increase in power and there is no warranty on these panels. Is having a warranty at 1200w vs no warranty at 1560w something to worry about?

I’m not sure how good most warranties are. If the panels are functional when picked up, that is the most important part of the warranty.

You really need to read the fine print of the warranty and usually manufacturers defects is a much shorter period than measured % of power output drop. In both cases, IMO most companies will be out of business 25 years down the road and not around to honor a 25 year warranty.

 

[Cmeister23]

I finally got lucky and just picked up 6 used LG 260w panels for $45 each.