Present Solar Option? - Page 2

Casey Freswick · 04-11-2023, 07:33 AM

The particular panels I was looking at are 55.28 x 27.76 inches. If I put them on the rear shell they will hang over about 10". That does not seem to be a good option. So is my only option the front shell? Or get a different dimension solar panel.

Wavery · 04-11-2023, 08:58 AM

Quote:

Originally Posted by Casey Freswick

The particular panels I was looking at are 55.28 x 27.76 inches. If I put them on the rear shell they will hang over about 10". That does not seem to be a good option. So is my only option the front shell? Or get a different dimension solar panel.

Hanging over is not harmful in itself but you would have to be very careful backing. If you accidently back into something (even slowly), it could do a lot of damage to your roof.

Before you decide on a panel, get the weight from the website. Put that much weight on the roof, then open the roof to see if that weight works for you.

If the weight is too much, you may be able to adjust the torsion bars. You may want to do that with the weight on the roof before you order panels. There may not be any adjustment left.

**rich2468** · 04-11-2023, 09:15 AM

Everyone's installation will be unique (depending on TM shell size, roof obstructions, weight/ amount of torsion bar assist available, budget, and the amount of solar charging wattage desired)- but to address your immediate statement/ question: I would not want anywhere near 10 inches of solar panel overhang.

That much would likely interfere with use of a cover and could become of concern during high wind days. Additionally, I'd be concerned with where the mounting points would lie on your rear shell. The shells have a centerline peak, as well as rounding towards the rear.

For my 2922KB, I overcame the slope/ curvature issues by building an aluminum rail mount for my solar panel array, but I don't think that approach would make sense for TM's with smaller rear shells (or older torsion bars without additional weight capacity).

My rear shell solar array hangs over the rear about 4" which is about as far as I think is practical in most cases.

Rich and Lynn
2021 2922KB

Casey Freswick · 04-11-2023, 10:46 AM

I was pretty sure my overhang was a bad idea, now I know.

. So here is my next option. Thanks for letting me run my ongoing internal debate with you all.

My main objective is related to my 20 year old 3 way fridge. If propane is how it should work best it is hardly working at all. Cost for new 3 way fridge is getting very expensive. It would be cheaper get a 4.5 cu ft 110 fridge running off of my 3000 watt inverter. The fridge draws about 300-500wh per day. (My 200W solar panels supplement about 800-1200wh per day: Wavery). So If I got 3 100 panels they would fit on the back shell (100 watt 12 volt. Product dimensions: 980 x 530 x 30mm (38.58 x 20.87 x 1.18 in). I am convinced that this would also give me plenty of solar power for my needs.

I would assume my best option for a controller would still be the one recommended by rickst29 (You need 30A output capability and 100 volt input voltage limit. The highest quality would be this one, it can be monitored and configured from a cellphone app. https://www.victronenergy.com/solar-...-100-30-100-50.)

One other plus, at this moment newpowa is selling 100 watt panels for $88.

https://www.newpowa.com/100w-monocry...hoCKJgQAvD_BwE

**rickst29** · 04-11-2023, 02:03 PM

The "new and little one" supports the 200W panel on the rear shell. That panel is mounted with the length going street side to curb side, because a 2619 rear shell has only about 30" of shell roof sticking out in closed position.

The solar controller for the "tiny" rear shell handles only my single 200w panel. That SCC is hidden in under-the-bathtub-ledge space, next to the WFCO. (I hope to never see it again.) I have the solar wires coming down the street side rear lift arm, all by themselves.

My larger front shell solar controller handle the other panels, all on the front shell. On a really great day they can reach around 450 watts at "noon".

My rear shell mounting of a solid panel SIDEWAYS had issues.

The far rear roof line of the shell, just above the bend, has only a slight incline from the street side and curb side edges. With extra layers of VHB tape in the rear corner mounts, I was able to make decent contact with 4 mounts along the TM back edge.

But the "front long side" of long aluminum+glass mounted this way has to mount flat over a much more curved section of roof,so I used only 2 mounts for the front "long side" of my panel (in the shadow of he front-panel mounted Air Conditioner).

This is much weaker than my flex panel mounts, but I do not anticipate any issues. (I taped down all of my flex panels around the entire perimeter, with gaps, using 4-6x more VHB surface area than the six Z brackets provide.)

A pair of mounting bars, crossing the full width of the panels plus a couple of extra inches on either side, could also have a lot more contact areas with the roof. But I have no idea where to buy only 6 feet of such mounting at low cost.

Casey Freswick · 04-27-2023, 07:22 PM

I made the decision. I already already have a lithium battery. I have a 1500 watt inverter. I already wired an inverter powered 120 Amp plug on the refrigerator wall. So I removed my 3 way refrigerator and purchased a Magic Chef 4.4 cu. ft. Mini Fridge in Stainless Look from Home Depot for $200 (originally $250, but I get 10% military discount and the box was torn so they took off another $25). I thought these were the best dimensions of any fridge that I saw. I had to cut some trim away on the side and top. I then secured the fridge with foam insulation and a 4" wood bolt through the frame at the back. I am sure this will not move. I purchased 3 100 watt solar panels for $72 each and also a controller for about $250. Solar powered electric refrigerator way cheaper than a $1,350 3 way fridge and much more versatile.

Casey Freswick · 04-27-2023, 07:25 PM

the fridge draws 70 watts, so I figure I have about 24 hours of battery power without any solar. Under most conditions it should work. But I will find out in the coming months.

Wavery · 04-29-2023, 06:56 AM

Quote:

Originally Posted by Casey Freswick

the fridge draws 70 watts, so I figure I have about 24 hours of battery power without any solar. Under most conditions it should work. But I will find out in the coming months.

What battery(s) do you have?

Casey Freswick · 05-01-2023, 06:16 AM

I have 1 150 Amp lithium battery, But I think it is more like a 100 AMP. I estimate the fridge will run for about 24 hours with no recharge at all. I also have a generator that can run my AC. I like to be prepared for boon docking, dispersed camping, but in reality do camp most often in state campgrounds with electric hook up. But not always.

Wavery · 05-01-2023, 08:07 AM

Quote:

Originally Posted by Casey Freswick

I have 1 150 Amp lithium battery, But I think it is more like a 100 AMP. I estimate the fridge will run for about 24 hours with no recharge at all. I also have a generator that can run my AC. I like to be prepared for boon docking, dispersed camping, but in reality do camp most often in state campgrounds with electric hook up. But not always.

I was actually curious about the brand battery. I'm also curious about your inverter. If your inverter is not "Pure sinewave", your fridge won't last long. It must have a pure sine wave inverter. A modified sinewave inverter will also draw more wattage from your battery.

You have plenty of battery and solar (for your stated usage). As long as you have the appropriate size wiring and proper fuse protection, you should be good on all but the days with bad cloud cover. Try to find campsites without trees. Shading can be a real issue.

The other thing that you need to think about is your WFCO converter's battery charger. Be sure that it is set for AGM batteries (if possible on your model). You don't really need a charger made for lithium. However, you will need to run larger (pure copper) wiring from the charger to the battery.

The WFCO charger is really made for lead acid batteries. The max charge amperage of your WFCO may be 45A but it can only handle 45A (bulk charge rate) for a very short period of time before it switches to about 10-15A for the duration of the (absorption) charge. This works perfectly for L/A batteries but poses a stress issue on your charger with lithium batteries.

The lithium battery has little to no internal resistance and resistance is what tells your charger when to lower the charge rate amperage. If you use the WFCO charger to charge your lithium battery, the charger will run at full charge rate of nearly 45A for the duration of the charge. The WFCO charger just isn't designed to take that heat and it's life will be severely shortened.

You may want to consider changing the WFCO charger to a far superior Progressive Dynamics charger. It's a pretty EZ job and if you're interested, one of us (that have done it) can give you instructions.