Community Forums

David 70 · 01-18-2025, 12:42 PM

I am in the process of trying to figure this solar process. I changed my absorption fridge over to a 12v dual compressor cooling unit from JC Refrigeration. I have two GC2 golf cart FLA batteries.
I have looked at the E Trailer and the Rec Pro units. I'm thinking of around 400 watts. My question is for recommendations where to buy solar and also the different solar controllers. I did install a Victron shunt this fall to monitor the batteries.

SafariBen · 01-18-2025, 02:02 PM

Surplus or used commercial panels are a good value. I can't comment on what's available in the specialty RV or mail order markets, traditionally they've been overpriced and poor quality panels. The problem is PV is cheap, but shipping a large panel is not, so you have to find a local reseller, or pay shipping on smaller panels. Locally, I could buy 300w for $150, or a couple hours away $85 for that same 300w range. Go further and $40/240 and even cheaper is easy to find, though the cheaper they are, the less likely they'll sell one or two panels.

An MPPT charge controller is the main thing you'll need, victron is available lots of places.

R Cabesa · 01-19-2025, 03:36 PM

The ONLY thing important about your solar panel selection is size dimensions to fit the most watts on your roof as possible. The mppt size etc can be figured from there. Used and craigslist panels are cheap.
You won’t go wrong with Victron gear. Most of mine is 5+ (I have added a few bits over time) years old.

Series vs. parallel of panels can change your SCC selection

Good luck , have fun. Check back in

David 70 · 01-19-2025, 06:17 PM

I am figuring on 4 200-watt panels. With a 39' unit there is a lot of room. My next question is what is best for a controller? A PWM or an MPPT? The one that's listed with it is a PWM and it mounts flush on the wall and the wire connections would be on the outside of the wall. I will let everyone know what I decide when I do but it may be early summer so don't think I have abandoned this post. Any more suggestions are welcome. The panels I am looking at are the monocrystalline. I am just a little leery of buying used ones. Around here solar has not been a big thing until the last few years. Most of what is getting put in are the big solar farms. Very little private installs on houses or anything.

SafariBen · 01-19-2025, 09:45 PM

I would much rather have used or surplus COMMERCIAL panels than smaller panels. I don't know all of what's out there, but the smaller panels tend to be overpriced and poor quality. When they put up acres of panels, there will be many pallets of panels left over, or scratch and dent, that are often disposed of, sometimes sold off. Anything sold with PWM is suspect right off the bat. MPPT at higher voltage is vastly superior for more than a tiny system.

TechWriter · 01-20-2025, 01:48 AM

Quote:

Originally Posted by David 70

I have looked at the E Trailer and the Rec Pro units. I'm thinking of around 400 watts. My question is for recommendations where to buy solar and also the different solar controllers. I did install a Victron shunt this fall to monitor the batteries.

Check out NAZ Solar Electric. I bought 365W REC Solar N PEAK 2 panels from them and am very happy with the panels.

Finally, I suggest Victron SmartSolar MPPT charge controllers.

Here's my setup.

B-Man · 01-20-2025, 06:23 AM

SafariBen is spot on - new or used commercial panels are the way to go, if you can find them locally. I just bought a pallet of 30 new Canadian Solar 395 watt panels for $85 each. I later went back for 2 more panels and paid $99 each.

I found multiple "local" solar panel vendors on FB Marketplace, including the one I ended up purchasing from.

David 70 · 01-20-2025, 08:53 AM

I found a couple close to me so I'm waiting for an answer.

Stircrazy1 · 01-20-2025, 10:27 AM

Quote:

Originally Posted by David 70

I am in the process of trying to figure this solar process. I changed my absorption fridge over to a 12v dual compressor cooling unit from JC Refrigeration. I have two GC2 golf cart FLA batteries.
I have looked at the E Trailer and the Rec Pro units. I'm thinking of around 400 watts. My question is for recommendations where to buy solar and also the different solar controllers. I did install a Victron shunt this fall to monitor the batteries.

so if you haven't bought anything yet, I will make a suggestion.
when looking for panels there are two ways to do it, the first buy a lot of little panels and put them all over the place. the second is to get the largest and best panels you can put on the roof. I sugest the later.

going with fewer bigger panels simplifies things with wiring and such. I would also sugest you look at a lot more than 400 watts if you have a 12V compressor fridge.

what I suggest is to get up on the roof and do some rough measuring of the open areas then go looking at physical size of larger panels. when I did mine I made a couple carboard cutout the size of the panels so I could place them up there and see how they fit and how close to obstructions they were.

so if you have the room, I would sugest a couple 350 to 450 watt panels. panels are the cheepest part of the system and there isent going to be to much difference between a 200 watt panel and a 400 watt panel now days.

what you could even do, if money is a huge concern right now, is plan where you could fit two large panels on the roof and just buy one for now. pickj up the proper MPPT controler for two panels, and then later it is just a matter of grabing another panel and adding it to the system. But, if you can aford two panels it is always better to set them up at the same time and then its done.

I am thinking you will need to add a couple more GC batteries depending on what else you run but that is somthing you can do later after you see how things go.

as for purchasing, look for a solar wholesaler that is fairly close to you if you plan on mounting them yourself. or one that has wherhouses all over that would be a reasonable drive for you to go pick up. I got mine up here 5 years ago for about 200 cdn a panel so about 140US (5 years ago) for a 325 watt split cell panel. now I can get a 400 to 450 for close to the same price.

spesking of panels go for the 24V panels and if you can buy a split cell. the 24v panels are general more efficient when hooked up to a MPPT controler and the split cell design makes them more efficient in low light conditions so cloudy, light shade etc.

I am not sure if this suplier is decient or not, but here is a example of a panel that has a good efficiency and is reasonably priced. two of these would power your fridge deicenty, have your batteries topped up fast in the morning and leave you power to spair, if you don't use much power. if you have an inverter they would allow for a fair bit of power usage.
https://ussolarsupplier.com/products...cb96a266&_ss=c

David 70 · 01-20-2025, 10:42 AM

stricrazy1; thanks or the info. There is a guy about 20 miles from me that is selling solar setups. He advertises the large solar farm type of setups. I will get in touch with him in the next several days. It is -10 degrees here right now, so I am trying to hide inside as much as possible. It gives me time to research this project. I am leaning towards two of the higher wattage panels rather than all the smaller ones. Hopefully he will know what I will need in order to hook them up to the rv. Thanks to all who steered me in this direction.

SJ-Chris · 01-20-2025, 06:56 PM

Buy used panels and save a fortune!

Facebook Marketplace or craigslist. Just check them with an volt/amp meter first.

You can also check with residential and commercial solar installation companies...they often remove 5-10 year old systems for people and then they want to sell those used panels for cheap.

Example: I've bought 250w panels for $35 each. 100w panels for $25 each. I've even seen solar panels for free.

If you are thinking about 400w....buy USED panels and put on 500-600w for 1/3rd the price of new panels.

Good luck!
Chris

ocbizman1 · 01-20-2025, 07:49 PM

My rig came with one 175w panel and 2 LA batteries totaling 100ah. Basically this just took care of the 12v fridge and little else.

I added 4 more 200w panels and swapped the batteries out to 2 LI totaling 400ah. I have an MPPT controller and added an inverter. Now even with cloudy skies we can go 3 days. Wife gets to use her hair iron, we can stream movies and use the microwave without concern when we are boondocking.

My 2 cents is to add the most panels and the most expensive system you can afford.

Stircrazy1 · 01-21-2025, 10:21 AM

Quote:

Originally Posted by David 70

stricrazy1; thanks or the info. There is a guy about 20 miles from me that is selling solar setups. He advertises the large solar farm type of setups. I will get in touch with him in the next several days. It is -10 degrees here right now, so I am trying to hide inside as much as possible. It gives me time to research this project. I am leaning towards two of the higher wattage panels rather than all the smaller ones. Hopefully he will know what I will need in order to hook them up to the rv. Thanks to all who steered me in this direction.

those are the best places to get them from if your not in a hurry. if you get to know an installer they could add one or two panels to there next big install order and you could purchase them. sometimes it is a benefit for them if it makes it a full palett they are ordering for shipping.

David 70 · 01-21-2025, 10:28 AM

Thanks, I plan to stop and see him in the next few days. It was -16 here this morning so I will stay inside where it's a little warmer. His website looks like he has a lot of panels on hand unless he is showing pics off the internet, I will find that out when the weather warms up. I have no intention of doing anything until April sometime unless it gets to be an unusually warm March. My home and auto insurance is coming due here in a couple of weeks, UUGH.