solar panel connectors

Right and then add in over paneling on top of that. Heat and electronics long term...

When I did the mixed panel test it was by adding the 230w to the other three panels. At times the 980w was producing 750-800w down and over 130 Voc. Yet the controller was only using 660w when the demand called for more. I believe the over paneling and high voltage caused it to reduce the output just like my Eco-worthy does when it gets hot.

That's why I don't like over paneling. I understand the concept but you are cooking your controller everyday.

Salvo wrote:
Yep, that's what I've been saying. A big series string resulting in a big voltage differential between a 12V battery and the operating Vmp is not a good design. You get poor efficiency. The charge controller will get hot.

Better to go with a series-parallel string (if using 4 panels) or just parallel when using 3 panels.

JiminDenver wrote:


I've been testing the 3 250w's in series and two things. The controller gets hot bucking down those voltages and I'm losing amps in the process. Each panel peaks at 18.5a alone but peak in series is 45-50a.

In the compartment you run the risk of the acid fumes damaging the controller. It may be okay if the compartment is vented well enough or with AGM. What's the distance outside of the compartment?

Ok the next thing is it OK to mount the controller in the front compartment where the batteries are they are in there own covered boxes and vented. That will put them within a foot of the controller.

Yep, that's what I've been saying. A big series string resulting in a big voltage differential between a 12V battery and the operating Vmp is not a good design. You get poor efficiency. The charge controller will get hot.

Better to go with a series-parallel string (if using 4 panels) or just parallel when using 3 panels.

JiminDenver wrote:


I've been testing the 3 250w's in series and two things. The controller gets hot bucking down those voltages and I'm losing amps in the process. Each panel peaks at 18.5a alone but peak in series is 45-50a.

JiminDenver wrote:
Remember the big hail storm a few summers ago. It got my trailer totaled, took out siding, windows, dinged up lots of cars, etc. Lots of new solar out here and I didn't see any damage to any of it.

On the controller, don't just go for cost. There are a few using the lessor expensive controller here, they work. Just go beyond the price and check settings and features. Is it adjustable enough to fit your needs, does it have temp compensation and what does it do with it. I researched a lot of controllers both high and low end before settling on the TS-MPPT-60 for the big array. I still use the least expensive MPPT controller to run the portable.

When you are ready to mount, we can make sure those big panels are not going to flex or come off. Depending on the run to the battery I might be able to spare some 1/0 and a few lugs.

YEP I had to replace ac covers and one of the vent cover

30a on 510w? Toooooo small. My two 245w's put out up to 34a. Two of my 250w would be 37a.

Remember the big hail storm a few summers ago. It got my trailer totaled, took out siding, windows, dinged up lots of cars, etc. Lots of new solar out here and I didn't see any damage to any of it.

On the controller, don't just go for cost. There are a few using the lessor expensive controller here, they work. Just go beyond the price and check settings and features. Is it adjustable enough to fit your needs, does it have temp compensation and what does it do with it. I researched a lot of controllers both high and low end before settling on the TS-MPPT-60 for the big array. I still use the least expensive MPPT controller to run the portable.

When you are ready to mount, we can make sure those big panels are not going to flex or come off. Depending on the run to the battery I might be able to spare some 1/0 and a few lugs.

Almot wrote:
Run Morningstar string calculator for 2*255W in series to make sure the maximum Voc is below 150V at low temps like 20F for TS MPPT 45.

I haven't heard of big panels breaking on trailers - this has been discussed too, you can reinforce the panel frame and/or add more mounting brackets.

510W will harvest more energy than 400w, no matter what controller or series/parallel.

With Tyco connectors you need to buy Tyco extension cable (they exist), and Tyco Y-connectors if wiring parallel (don't know if these exist). Maybe shop around and find 2*255W with MC4, this type is prevalent, plenty of cables and connectors. 260W MC4, $234

Edit - PS: forget about string calculator for TS MPPT 45. 2*255W or 2*260 will never exceed 150V.

the cost for the big panel system with 45a MPPT about $906 and the 4 small with a 40a MPPT is $903 but I called Solar blvd and he said I could use a 30a MPPT and solar Blvd carries Tyco wire. I was going to use 6 anchor points on the big panels

Run Morningstar string calculator for 2*255W in series to make sure the maximum Voc is below 150V at low temps like 20F for TS MPPT 45.

I haven't heard of big panels breaking on trailers - this has been discussed too, you can reinforce the panel frame and/or add more mounting brackets.

510W will harvest more energy than 400w, no matter what controller or series/parallel.

With Tyco connectors you need to buy Tyco extension cable (they exist), and Tyco Y-connectors if wiring parallel (don't know if these exist). Maybe shop around and find 2*255W with MC4, this type is prevalent, plenty of cables and connectors. 260W MC4, $234

Edit - PS: forget about string calculator for TS MPPT 45. 2*255W or 2*260 will never exceed 150V.

OK here's what I have come up with 2 255w panels total 510 watts Morningstar ts-MPPT 45 or Renogy 4 100w panels total 400w with a 40a controller. They are close in cost. One problem I see is with the large 65'x38" panels is flex and possibly of breaking or hail I live in Colorado and its hails. I would gain 110w with them. pros or cons?