Free standing panels to inside MPPT controller

[MalibuDave42]

I'm a newbie looking some help... Here's my "current" plan - start with two 100w panels, then maybe add another 200w - Both sets would be portable\free standing. As I understand the math (which I may not )

• Maximum Power: 100W
• Open-Circuit Voltage (Voc): 21.6V
• Short-Circuit Current (Isc): 6.5A
• Optimum Operating Voltage (Vmp): 18.0V
• Optimum Operating Current (Imp): 5.56A
• Operating Temperature: 104℉-176℉
• Maximum System Voltage: 600VDC UL
• Maximum Series Fuse Rating: 15A

The bolded numbers above are the ones I need to pay attention to. So, 2 panels 43.2v @ 6.5a, when I add another set of panels 43.2v @ 13a. Correct?

For flexibility of panel placement: 1 40ft 10ga 2-wire cord with MC4 connectors; when\if the 2nd set of panels add a 2-1 MC4 connector to connect the set of panels together and connect to the 40ft line. Seem reasonable?

Inside my front bay, I am thinking to use a Victron Energy SmartSolar MPPT 100V 30 amp. Is that overkill? Or something smaller - Victron Energy SmartSolar MPPT 75V 15 amp? (note: If someday I decided to add permanent panels to my roof, I will add another controller.)

I would like to connect the "from PV" wires to an external plug mounted through my front bay wall. What plug should I use? I've seen one of these on a "factory" install SAE Power Socket Sidewall Port 12AWG but it does not seem like it can handle the current. Or maybe something like: Powerwerx PanelPole1-White, Panel Mount Housing. What are your thoughts?

WRT fuses: 1 50amp from the charge controller to battery. Do I need one just inside of the external plug heading to the charge controller?

Any and all input is greatly appreciated.

 

[Off Gridin' It]

I'm a newbie looking some help... Here's my "current" plan - start with two 100w panels, then maybe add another 200w - Both sets would be portable\free standing. As I understand the math (which I may not )

• Maximum Power: 100W
• Open-Circuit Voltage (Voc): 21.6V
• Short-Circuit Current (Isc): 6.5A
• Optimum Operating Voltage (Vmp): 18.0V
• Optimum Operating Current (Imp): 5.56A
• Operating Temperature: 104℉-176℉
• Maximum System Voltage: 600VDC UL
• Maximum Series Fuse Rating: 15A

The bolded numbers above are the ones I need to pay attention to. So, 2 panels 43.2v @ 6.5a, when I add another set of panels 43.2v @ 13a. Correct?

For flexibility of panel placement: 1 40ft 10ga 2-wire cord with MC4 connectors; when\if the 2nd set of panels add a 2-1 MC4 connector to connect the set of panels together and connect to the 40ft line. Seem reasonable?

Inside my front bay, I am thinking to use a Victron Energy SmartSolar MPPT 100V 30 amp. Is that overkill? Or something smaller - Victron Energy SmartSolar MPPT 75V 15 amp? (note: If someday I decided to add permanent panels to my roof, I will add another controller.)

I would like to connect the "from PV" wires to an external plug mounted through my front bay wall. What plug should I use? I've seen one of these on a "factory" install SAE Power Socket Sidewall Port 12AWG but it does not seem like it can handle the current. Or maybe something like: Powerwerx PanelPole1-White, Panel Mount Housing. What are your thoughts?

WRT fuses: 1 50amp from the charge controller to battery. Do I need one just inside of the external plug heading to the charge controller?

Any and all input is greatly appreciated.

Ok lets look at this one question at a time.

First you need pay attention to the VOC and IMP. Not the ISC.
It looks like you are planing on running the two 100 watt panels in series for a 200 watt array. This would produce 43.2 volts at 5.56 amps.
If you do add an addition 200 watts just add those to the series so you have four panels in series.
This would produce 86.4 volts at 5.56 amps.
You want the low amps because you are making a VERY long run to the charge controller and lower amps is less resistance and less heat.
Also the higher voltage will get you charging earlier in the day and keep you charging later at night.

Without knowing the voltage of your battery bank I can't tell you about the charge controller so let me know that info and I can advise you on that.
After I know that I can give you some options and also talk about the best exterior plug for you to connect the array to the house.

 

[Bud Martin]

BTW, add about 15 ~ 20% to the total VOC in cold weather so it will not exceed the max PV inPut Voltage of the SCC.

 

[MalibuDave42]

I am using 4 Interstate 9-GC2-UTL 6v golf cart batteries labeled 210ah each. They are connected in series and parallel. As I understand it, 12v @ 420ah of which 210ah is usable since they are flooded batteries.

Adjusting VOC for cold - 86.4 * 1.2 = 103.68 volts 5.56 amps. Does that rule out Victron Energy SmartSolar MPPT 100V 30 amp?

Also note: this is a 5th wheel RV install.

Do I have this right? A MPPT charge controller coverts my 86.4v @ 5.56a to 14.17v @ 33.90a. It will use 33.90a to bulk charge, then monitors the battery voltage to step down to absorption then float charging.

 

[rmaddy]

The bolded numbers above are the ones I need to pay attention to. So, 2 panels 43.2v @ 6.5a, when I add another set of panels 43.2v @ 13a. Correct?

This assumes the first 2 panels are in 2S and then when you add two more the 4 panels are in 2S2P. If you combine all 4 in series then it would be 86.4V @ 6.5A.

WRT fuses: 1 50amp from the charge controller to battery. Do I need one just inside of the external plug heading to the charge controller?

1. You linked to a breaker, not a fuse. Big difference. You can use either one. The type of breaker you linked to is good since it can act as a disconnect.
2. The size of the breaker (or fuse) between the SCC and battery should be based on the output of the SCC. If you get a Victron 100/30 then the SCC will have a max output of 30A to the battery. So a 40A breaker or fuse would be fine. If you get a Victron 75/15 then a 20A breaker/fuse is fine. Basically look at the second number (in Victron's SCC naming scheme the 2nd number is the max amps output to the battery) and multiply by 1.25 and round up to the nearest available breaker/fuse size.

Adjusting VOC for cold - 86.4 * 1.2 = 103.68 volts 5.56 amps. Does that rule out Victron Energy SmartSolar MPPT 100V 30 amp?

You get 86.4V from 4 panels in series. Yes, it does rule it out since 103V > 100V. But keep in mind that to get a 20% increase in Voc you need the panel temperature (not the air temperature) to be down to about -30ºC (-22ºF). But the exact number depends on the V temp coefficient of your specific panels. Most panels are in the area of -0.3%/ºC. Some are lower and some are higher. Look at the spec sheet for your panels.

But you also don't want the cold Voc to be really close to the SCC's max input voltage on a regular basis. You probably don't want to be at 99V for weeks on end.

 

[Just John]

I would like to connect the "from PV" wires to an external plug mounted through my front bay wall. What plug should I use? I've seen one of these on a "factory" install SAE Power Socket Sidewall Port 12AWG but it does not seem like it can handle the current. Or maybe something like: Powerwerx PanelPole1-White, Panel Mount Housing. What are your thoughts?

WRT fuses: 1 50amp from the charge controller to battery. Do I need one just inside of the external plug heading to the charge controller?

The important part first, don't go cheap with fuses or breakers. You don't want cheap, you want reliable. Pay attention to voltage ratings, for the panel side, you want to use fuses, circuit breakers are good for the battery side since most are limited to 48v. Higher voltage DC-rated circuit breakers are available, but you pay more.
If they have the size you need, I can recommend either of these two:

Eaton Bussmann 187F Series Resettable Waterproof Circuit Breaker Surface Mount up to 200A

Marine Rated 187 Series Circuit Breaker features a manual switching and heavy duty circuit protection from 50 to 200 Amp loads. Type III waterproof circuit breakers are typically used in automotive auxiliary and DC accessory branch circuits for trucks, buses, RVs and marine applications.

powerwerx.com

Eaton Bussmann 285 Series Resettable Circuit Breakers Surface Mount up to 150A

These high-amp, Type III circuit breakers are typically used in automotive auxiliary and accessory circuits for trucks, buses, RVs and marine applications. High-amp circuit breakers also have applications in battery charger systems and DC audio systems.

powerwerx.com

What type of plug to use is up to you, but the SAE plug is not what I would pick.

https://powerwerx.com/panelpole-panel-mount-powerpole-white-single

Powerpole is better, but still not the best. Definitely upgrade to the 45 amp connectors if you go that route. Neither connector is waterproof, MC-4 is, but of course not as pretty.

 

[MalibuDave42]

The important part first, don't go cheap with fuses or breakers. You don't want cheap, you want reliable. Pay attention to voltage ratings, for the panel side, you want to use fuses, circuit breakers are good for the battery side since most are limited to 48v. Higher voltage DC-rated circuit breakers are available, but you pay more.
If they have the size you need, I can recommend either of these two:

Eaton Bussmann 187F Series Resettable Waterproof Circuit Breaker Surface Mount up to 200A

Marine Rated 187 Series Circuit Breaker features a manual switching and heavy duty circuit protection from 50 to 200 Amp loads. Type III waterproof circuit breakers are typically used in automotive auxiliary and DC accessory branch circuits for trucks, buses, RVs and marine applications.

powerwerx.com

Eaton Bussmann 285 Series Resettable Circuit Breakers Surface Mount up to 150A

These high-amp, Type III circuit breakers are typically used in automotive auxiliary and accessory circuits for trucks, buses, RVs and marine applications. High-amp circuit breakers also have applications in battery charger systems and DC audio systems.

powerwerx.com

What type of plug to use is up to you, but the SAE plug is not what I would pick.

https://powerwerx.com/panelpole-panel-mount-powerpole-white-single

Powerpole is better, but still not the best. Definitely upgrade to the 45 amp connectors if you go that route. Neither connector is waterproof, MC-4 is, but of course not as pretty.

What connection do you recommend? Reminder: This for a through-wall connection port for my 5th Wheel.

 

[Just John]

What connection do you recommend? Reminder: This for a through-wall connection port for my 5th Wheel.

If it is a permanent connection, use a cable gland. I like the powerpole connectors, but that is just my preference. You can get environmental boots for the 50 amp rated connectors.

https://powerwerx.com/anderson-36055p2-sb50-environmental-boot-source

 

[MalibuDave42]

A permanent port, not a permanent connection. I plan to store the panels inside my 5th wheel, deploy them to the ground, connect to the port after deployment. I am thinking I would like to add a through-wall connector "under the 5th wheel overhang near the hitch" so they are semi protected from the weather (but if there is sideways rain, the connection could get wet). This Powerwerx PanelPole1-White, Panel Mount Housing will be protected while traveling but only semi-protected while plugged in. Do you know of something more weathertight in both - travel (plugs only) and while connected (wires inserted)?

 

[Just John]

A permanent port, not a permanent connection. I plan to store the panels inside my 5th wheel, deploy them to the ground, connect to the port after deployment. I am thinking I would like to add a through-wall connector "under the 5th wheel overhang near the hitch" so they are semi protected from the weather (but if there is sideways rain, the connection could get wet). This Powerwerx PanelPole1-White, Panel Mount Housing will be protected while traveling but only semi-protected while plugged in. Do you know of something more weathertight in both - travel (plugs only) and while connected (wires inserted)?

Just keep them out of standing water and they should be fine. I would upgrade to the 45 amp rated pins, but hams use powerpole all the time.