I am installing rooftop solar system on my 21’ travel trailer. I know that it’s ideal to have 2 pairs of panels, and connect them in series and then in parallel. Unfortunately, I only have enough space for 3 100w panels. Is it possible to connect the 3 panels in both series, than parallel? If not, how do I connect 3 panels in parallel?
How to connect three 100w panel array?
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3 panels all paralleled together in a combiner box, or using parallel connectors to a single pair of cables of sufficient size to handle the wattage.
What voltage are your panels?
What voltage are your panels?
If your solar charge controller can handle it, I would connect the three panels in series. That's a lot easier than connecting three in parallel.
If you do parallel, you'll need a 3-into-1 Y connector as well as inline fuses for all three.
If you do parallel, you'll need a 3-into-1 Y connector as well as inline fuses for all three.
Just Series connect all 3 panels.
At 22Voc each that is only 66Voc total.
Any MPPT SCC can handle that.
What brand and make of SCC do you have? Amps? Max volts input?
You can series connect panels without parallel.
What are your battery specs?
Careful. I have seen 72V
That is why I asked what voltage his panels were.
Careful. I have seen 72V 100W panels.
That is why I asked what voltage his panels were.
The panels are 100w.
@Frobisher: I will be purchasing a 40A MPPT Controller
Dropped a 100a Battleborn lithium about 15 months ago.
Installed a VICTRON 712 BVM 15 months ago
No backup generator
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Let me provide some background information: I bought my first trailer about 14 years ago to support my hobby of retriever training for AKC Hunt tests & field trials.
As 90-95 percent of my trips involve dry camping, I added a 2nd deep cell lead acid battery, mounted a 4000/3400w generator on its back porch, and added a couple of 12 volt outlets. This worked very well for me.
I upgraded from my19’ trailer to a 21’ trailer 18 months ago. I decided to take advantage of technology not available when I purchased my 19’ trailer, and made plans to add a solar system this year.
In preparation to going solar, I added a 100w Battleborn lithium battery & Victron 712 BVM. I also installed 12 volt outlets throughout the trailer’s cabin. Then I went camping.
In answer to your question, I do not normally seek out shade. But sometimes I end up in shady areas. I do experience rainy, overcast weather, as I winter camp in Northern California & the Pacific Northwest. That’s one of the reasons I want more wattage on my roof.
I originally planned to install two 200w panels on either side of my sunroof. Unfortunately, those panels were too wide for that area. This forces me to purchase three, narrower 100w panels.
Two of these panels will be mounted on either side of the sunroof, located in the front third section of the trailer. The AC cover is located directly behind the sunroof. The third panel will be located next to the AC cover, on the street side of the roof (nose to nose with the other panel). There is absolutely no space for a 4th panel.
A roof vent is located on the starboard side of the AC, within a couple of feet from the lone, starboard side panel. This is where I plan to feed to solar cables into the cabin.
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I believe I should parallel connect the panels. The third panel will be placed next to the AC shroud. So I must assume that panel will be in shade once in a while.
The other two panels will be on either side of a sun roof, and free of shadows from the AC or roof vents.
You didn't answer my question, but since you are sure parallel is the best option it doesn't matter.
The choices for parallel are combiner connections that are prone to failure.
Or some form of combiner box.
They can be combined on the roof, or in the basement work area.
If on roof, only two wires need feed the basement, but it has to be large wire, and fused to prevent fires from shorts etc.
You could mound a weatherproof box on the roof, feed in the positives to a bussbar or junction connector, then feed the main wire capable of the max amps of all 3 panels for the distance of the conductor circuit.
Or, feed all 3 pairs down to the basement, mount a square D QO panel, and tie all feeders to a breaker., then feed the main lug wire to the charge controller.
I’m deciding between these 2 products. I’d appreciate some input regarding how the HQST panel compares against the RICHSOLAR. Because I lack roof space, I prefer the dimensions of the HQST. Every inch saved ...
HQST Compact Design 100w Mono Solar Panel
* Maximum Power: 100W
* Maximum System Voltage: 600V DC (UL)
* Open-Circuit Voltage ( Voc ): 24.6V
* Optimum Operating Voltage ( Vmp ): 20.6V
* Optimum Operating Current ( Imp ): 4.85A
* Short-Circuit Current ( Isc ): 5.28A
* Weight: 9.92 lbs
* Dimensions: 39.65x19.61x1.18 in
Warranty Information
* 25-year power output warranty: 10 year/90% efficiency rate, 25-year/80% efficiency rate
* 3-year material and workmanship warranty
RICHSOLAR 100w Mono
Specifications
* Maximum Power(Pmax): 100W
* Maximum Power Voltage(Vmp): 18.2V
* Maximum Power Current(Imp): 5.49A
* Open Circuit Voltage(Voc): 22.1V
* Short Circuit Current(Isc): 5.93A
* Maximum System Voltage(Vmax): 600V DC
* Weight: 16.5 lbs
* Dimensions: 46.7 x 20.1 x 1.4 in
HQST Compact Design 100w Mono Solar Panel
* Maximum Power: 100W
* Maximum System Voltage: 600V DC (UL)
* Open-Circuit Voltage ( Voc ): 24.6V
* Optimum Operating Voltage ( Vmp ): 20.6V
* Optimum Operating Current ( Imp ): 4.85A
* Short-Circuit Current ( Isc ): 5.28A
* Weight: 9.92 lbs
* Dimensions: 39.65x19.61x1.18 in
Warranty Information
* 25-year power output warranty: 10 year/90% efficiency rate, 25-year/80% efficiency rate
* 3-year material and workmanship warranty
RICHSOLAR 100w Mono
Specifications
* Maximum Power(Pmax): 100W
* Maximum Power Voltage(Vmp): 18.2V
* Maximum Power Current(Imp): 5.49A
* Open Circuit Voltage(Voc): 22.1V
* Short Circuit Current(Isc): 5.93A
* Maximum System Voltage(Vmax): 600V DC
* Weight: 16.5 lbs
* Dimensions: 46.7 x 20.1 x 1.4 in
Sorry, I thought I answered your question.
Each solar panel is 100w rigid mono. In post #11, I provided the specs for the two products I am deciding between. The 2 sets of specs are slightly different, so I’d appreciate some feedback on which panel is preferable. If everything balances out and the two products are equally efficient, I’ll purchase HQST compact panels.
If I my choices are limited to parallel or series, I believe I’d be better off with parallel. But I’m seeking advice. If you believe I’d be better off connecting in series, I would appreciate your reasoning.
What size wire are you suggesting? I was planning to feed the solar cables through my refrigerator vent located mid roof, and close to where the solar panels will be mounted.
I was planning to order 10 gage wire with MC4 connectors. And use 8 gage wire from the solar controller to the battery. If I need smaller gage wires, i’d Need to find another supplier.
You actually solved a puzzle that came up yesterday. I was looking at a picture of a rooftop combiner box & wondered why they didn’t use parallel connectors. This approach is doable. However, this is a Fiberglass trailer, so I would have to paste it to the roof.
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The question was what voltage.
Your specs show the info, so all is good.
Another option might be the windynation thin rail panels.
They are smaller than standard 100W panels, the frame is only 3/4" thick instead of the standard 1.5" frame.
I have 3 mounted on the roof of my suburban easily, and could fit a fourth...
There is a thread on here discussing them.
Search for windynation...
They are smaller than standard 100W panels, the frame is only 3/4" thick instead of the standard 1.5" frame.
I have 3 mounted on the roof of my suburban easily, and could fit a fourth...
There is a thread on here discussing them.
Search for windynation...
Thanks for your suggestion. Checked out your suggestion. Could not find that thread. But I did get on the Windynstion websitreem to be short on inventory.
My interest in RichSolar & HQST stems from Will’s strong recommendations. He particularly liked the thickness & quality of these panels’ frames. So I want to stick with these options.
If you are parallel connecting the 3 panels then the HQST with the higher 20Vmp would be better overhead for a MPPT SCC on a 12V battery.
Lower amps too for x 3 panels
Lower amps too for x 3 panels
@HRTKD: I found 3 panel parallel connectors on Will’s DYI site: https://www.amazon.com/Renogy-Solar...BWV9/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1
@Supervstech: I also found a Amazon link for a waterproof junction box as well as cable feeders for my rooftop refrigerator vent and junction box (should I go with your suggestion).
I’m moving on to wiring. Per suggestions from this thread, I tentatively plan to use 8 gage cables between the panels and the solor controller. And 6 gage cables between the [40 Amp MPPT] solar controller and my lithium battery.
Once again, via Wills DYI site, I found this link to Amazon/windy nation wires. This product does satisfy my need for 8 gage solar cables of varying length. Although several reviewers found this wire too rigid, this product recieved high marks.
https://www.amazon.com/WindyNation-Extension-Connector-Variety-Available/dp/B01L6OU6BG/ref=as_li_ss_tl?dchild=1&keywords=solar+panel+hookup+wire&qid=1590862630&sr=8-6&linkCode=sl1&tag=vehicledwelling-20&linkId=d1396752e4ddeed09db7e2a2a730d0c4&language=en_US&th=1
The challange is that the refrigerator vent will deliver the solar cables to the mid section, starbard side of the cabin. The battery is located in the front of the cabin, on the port side.
I have several options regarding placement of the solar controller:
I'd like some input if 8 gage wiring is large enough as the controller moves further away from the panel array. Also some options for the placement of a fuse and/or circuit breakers. I need to fully understand @Supervstech's suggestions.
I'll probably also need some suggestions regarding suppliers.
I appreciate your help.
@Supervstech: I also found a Amazon link for a waterproof junction box as well as cable feeders for my rooftop refrigerator vent and junction box (should I go with your suggestion).
I’m moving on to wiring. Per suggestions from this thread, I tentatively plan to use 8 gage cables between the panels and the solor controller. And 6 gage cables between the [40 Amp MPPT] solar controller and my lithium battery.
Once again, via Wills DYI site, I found this link to Amazon/windy nation wires. This product does satisfy my need for 8 gage solar cables of varying length. Although several reviewers found this wire too rigid, this product recieved high marks.
https://www.amazon.com/WindyNation-Extension-Connector-Variety-Available/dp/B01L6OU6BG/ref=as_li_ss_tl?dchild=1&keywords=solar+panel+hookup+wire&qid=1590862630&sr=8-6&linkCode=sl1&tag=vehicledwelling-20&linkId=d1396752e4ddeed09db7e2a2a730d0c4&language=en_US&th=1
The challange is that the refrigerator vent will deliver the solar cables to the mid section, starbard side of the cabin. The battery is located in the front of the cabin, on the port side.
I have several options regarding placement of the solar controller:
- In a cabinet next to the refrigerator, about 15 feet from furthermost panels
- In a cubby hole in the front, starbard side of the cabin, about 30 feet from the panels and 10-15 feet from the battery.
- in the cubby hole where the battery is located, about 38-45 feet from the rooftop.
I'd like some input if 8 gage wiring is large enough as the controller moves further away from the panel array. Also some options for the placement of a fuse and/or circuit breakers. I need to fully understand @Supervstech's suggestions.
I'll probably also need some suggestions regarding suppliers.
I appreciate your help.
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Baughb
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I use this for 3 Renogy 12V 100 watt panels to combine in parallel. The panels are all different in that 1 is a suitcase kit that I bypass the mppt charger, 1 is a rigid panel, and 1 is a portable, soft, folding panel. I try to terminate as many connections into Andersons as possible. Very convenient, no polarity guessing, pretty simple.
powerwerx.com
4 Position Power Distribution Block for 15/30/45A Powerpole Connectors
Easy to use 4 position power distribution block for 15/30/45A Powerpole connectors. Innovative design allows any position to be used as a DC power Input or Output as they are all connected together. In addition, each position can use the optional PCLIP retention clips for secure operation. Thick...
powerwerx.com
Just remember... Anderson power pole connectors are NOT keyed. And they pop apart easily. So, other than color, they have nothing keeping them from plugging in the wrong polarity.I use this for 3 Renogy 12V 100 watt panels to combine in parallel. The panels are all different in that 1 is a suitcase kit that I bypass the mppt charger, 1 is a rigid panel, and 1 is a portable, soft, folding panel. I try to terminate as many connections into Andersons as possible. Very convenient, no polarity guessing, pretty simple.
4 Position Power Distribution Block for 15/30/45A Powerpole Connectors
Easy to use 4 position power distribution block for 15/30/45A Powerpole connectors. Innovative design allows any position to be used as a DC power Input or Output as they are all connected together. In addition, each position can use the optional PCLIP retention clips for secure operation. Thick...
