System Compatibility???

SolarSteve

I'm setting up a little bit of solar for my RV up in Wisconsin. I'm trying to determine if my charge controller and panels are compatible.

I recently bought a Morningstar SunSaver MPPT 15A. Model SS-MPPT-15L. The panels I just bought are Sharp ND-123UJF 123 Watt 12 Volts 2 Solar Panel Kit. (That is actually a Sunforce Kit). Remember.... TWO 2 panel kit, so I have 246 Watts.

Both items were purchased off of Ebay, so no returns.

Today I stumbled on the Morningstar String Calculator. When I entered my panel info (Brand & Panel Number) it showed: "Exceeds maximum power rating."

The specs say about 7.15A per panel. Both panels running at optimum amperage (7.15x2) would still be under the 15A rating of the Morningstar Charge Controller?

And with the key word being "optimum" these panels would be used in northern Wisconsin, and hardly put out the "optimum." So I would think the two 2 panels would be OK with this controller? What do you guys think?

Thanks!
SolarSteve



Here are the panel specs:

ND-123UJF Information
Specifications (@ STC)
Pmax 123.00 Watts
Voc 21.78 Volts
Isc 7.99 Amps
Vmp 17.21 Volts
Imp 7.15 Amps
Voc Coefficient -0.0758 V/C
NOCT 49.20 C
Operation
Minimum Voc (average high temp.) 19.86 Volts
Max. Operating Voc (record low temp.) 21.34 Volts
Max. Voc (record low Temp., morning) 23.55 Volts
Minimum Vmp (average high temp.) 15.24 Volts
Maximum Vmp (record low temp.) 16.75 Volts

BB.

Re: System Compatibility???

You should be very happy with that setup... The maximum "Typical" current output from such an array should be around (assuming 12 volt bank):

• 246 watts * 1/14.5 volts charging * 0.77 derating= 13 amps

There may be days you could get more (cold/clear days/possibly with reflecting snow on the ground)--but for average warm weather it will be fine.

MPPT controllers (like the MorningStar) have output current built in--so they will not fry themselves if hooked to a larger array.

Also--you have a choice of placing the two panels in parallel or in series (Vmp=17.2 volts or Vmp=34.4 volts). Normally, if you have longer wiring runs between the Array and the charge controller--choose to put the panels in series (reduces voltage drop because of 1/2 the current flow). Or if you are in very hot regions, placing the panels in series is a good idea too (panel Vmp drops in warm/hot weather--may not be able to fully/quickly charge the battery bank on hot days).

With MPPT type controllers--Running the panels in series is usually a good idea all the way around (of course, there are voltage/current limits to worry about with larger arrays than you currently have).

Here is a nice thread with video from Keven in Calgary Canada that shows designing and installing solar PV in a small RV trailer.

-Bill

SolarSteve

Re: System Compatibility???

Thanks very much Bill for your detailed answer! I'm glad you approved and all looks well. When I fiddled a bit more with the "Morningstar String Calculator" I got a positive result confirming your analysis. I had the battery input voltages off a bit, and I didn't realize they were so critical. I needed to input 11.5V min, and 15.5 max, then I got the blessing!

The calculator now shows the optimal system:

2 modules in series per string
1 string in parallel
246 Watts Total
Optimal Configuration

Max Voc 47.09 V < 78.0V Vin Max
Min Vmp 30.47 V > 15.5V Vb Max
Max Vmp 30.50V

Now if I only knew what all these number mean?? I understand what hooking the 2 modules in series means, but that's about it. Sorry. Thanks again!

BB.

Re: System Compatibility???

SolarSteve wrote: »

2 modules in series per string
1 string in parallel

Different solar modules can obvious be in series, parallel, or series parallel connections to match the input voltage requirements of the controller.

Max Voc 47.09 V < 78.0V Vin Max

Solar panels are not ideal batteries at all... They have an operating voltage range of almost 2:1---From Voc (Voltage open circuit--no load voltage and very cold--Voc is "high") to Vmp-hot (voltage maximum power with very hot panels--Vmp is "low").

So, in this case, with no current draw (battery fully charged) and very cold panels, their Voc will be less than the ~75 volts DC input voltage limit of the charge controller--Any higher, and you run the risk of blowing the internal switching circuitry.

Min Vmp 30.47 V > 15.5V Vb Max
Max Vmp 30.50V

Min/Max Vmp is usually a wider range... Normally Vmp-min will be a very hot day with full sun on the panels (cell temperatures approaching 180F).

On very cold/windy days, the cell temperatures in full sun will be less than the ~77F STC test conditions--So Vmp will be higher than the paper specifications (usually only happens in sub freezing conditions).

So--The two general operating points that need to be confirmed with MPPT type charge controllers are, typically, the Voc-cold (less than maximum controller rated voltage) and Vmp-hot (greater than Vbatt-charging and a couple volt wiring+controller voltage drops).

To make thinks even more confusing--Battery charging voltages also vary with bank temperature... Colder batteries need higher voltages for proper charging--And hot batteries require lower charging voltages. So, sometimes for extreme conditions you also need to take the battery bank charging voltage at XX degree temperatures into account too (i.e., cold battery bank in basement with hot summer temperatures).

There are a lot of secondary effects in solar RE that can bite you... An MPPT controller with Vmp>>Vbatt-charging can help reduce those gotcha moments by quite a bit.

-Bill

SolarSteve

Re: System Compatibility???

Thanks for the further knowledge Bill. Very interesting and very daunting for a beginner. There sure is a lot to know for all the "ins and outs" of solar!!

A couple further questions please, while you're familiar with my set-up.

1. Wired the way we intend, with the 2 panels in series, what size wire would you suggest for a 30' run from the panels to the batteries? Then from the batts to the inverter is where you really need the "big guns" correct?

2. It's disappointing after having spent $200 for this Morningstar MPPT charge controller, that it doesn't have any metering gauges on it. How would you recommend I monitor the amps and voltages? Would Morningstar's RM-1 remote meter (for another $75!!) be my best choice?

3. Is there some factory made mounting rails for a system like mine? Or do you have to fabricate everything yourself? I would like to make some mounts for the roof of the RV. Aluminum angle stock, something like that?

Thanks again! Your help getting off on the right foot is greatly appreciated!!! (:

icarus

Re: System Compatibility???

One potential problem with wiring panels in series is that any partial shading on any one panel will dramatically decrease the output of the entire string. This is somewhat mitigated by diodes, but it is still a consideration. In my situation for example, I have panels that at any given time, one panel is often partially or completely shaded so if I wired them in series (24 vdc) it would decrease my over all harvest, as opposed to leaving them wired in simple parallel 12 vdc set up.

On an RV this may or may not be an issue, depending on if you are going to park the unit in a fixed location where the shading is controlled. One of the double edge swords of RV solar PV is most people like to have the RV in the shade to reduce heat gain, which of course makes it hard for a RV mounted PV to work very well. That is why some RVers tend to mount panels in a portable mount.

Icarus

BB.

Re: System Compatibility???

SolarSteve wrote: »

1. Wired the way we intend, with the 2 panels in series, what size wire would you suggest for a 30' run from the panels to the batteries? Then from the batts to the inverter is where you really need the "big guns" correct?

Normally, we look for 3% to 1% voltage drop in wiring (1% is better--but requires 3x as much copper--so more buck$).

Just google for voltage drop calculators--Here is a very simple calculator. Just use trial and error for your setup:

• Vmp 17.21 Volts (two in series = 34.4 volts):
• 34.4 volts * 3% = 1.03 volts max drop
• Imp 7.15 Amps; 30' one way run:
• 8 awg wire will give you 0.68 volt drop
• 10 awg wire will give you 1.08 volt drop

10 AWG wire (Direct burial type) is pretty easy to get at the home store--Certainly will work for your system. 8 AWG would be great--you choose the price point.

From the Charge Controller to the battery bank--I would aim for less than 0.1 volt drop on a 12 volt bank (0.05 would be better). Assume 3' one way run and 15 amps:

• 3' of 10 AWG wire @ 15 amps => 0.11 volt drop
• 3' of 8 AWG wire @ 15 amps => 0.07 volt drop
• 3' of 6 AWG wire @ 15 amps => 0.04 volt drop

You want the charge controller to very accurately measure the battery voltage while flowing current... For a 12 volt battery bank, 0.1 volts represents about 10% difference in resting storage capacity. A few tenths of a volt difference in charging voltage can reduce current flow to the battery -- wasting solar panel power and taking longer to recharge the battery bank (14.5 volts charging vs 14.2 volts as an example).

Keep the controller to battery bank cables short and don't scrimp on copper costs here (same thing with inverter DC input to battery bank connections).

2. It's disappointing after having spent $200 for this Morningstar MPPT charge controller, that it doesn't have any metering gauges on it. How would you recommend I monitor the amps and voltages? Would Morningstar's RM-1 remote meter (for another $75!!) be my best choice?

From my humble point of view--Your battery is the "heart" of your system. And you need to know the current going into and out of the battery bank -- A battery monitor is great for day to day operation/monitoring the battery bank (batteries not properly charged can die in months).

The Trimetric's are about 2x the cost of the MS Monitor--and probably more than 2x as useful.

One Xantrex and the Victron Energy battery monitors also have a contact that can be programmed as an alarm when state of charge falls below your programed set point.

3. Is there some factory made mounting rails for a system like mine? Or do you have to fabricate everything yourself? I would like to make some mounts for the roof of the RV. Aluminum angle stock, something like that?

Our host, NAWS sells some RV solar panel mounts... But you might do nearly as well if you get aluminum sections from the local home center--depending on your needs.

Have fun!

-Bill

SolarSteve

Re: System Compatibility???

You guys are the BEST!!! Thank you ICARUS for your advice as well. That's makes a lot of sense what you said about the shading with an RV.

One last question please...

On my Morningstar SS-MPPT-15L controller there is connections labeled: LOAD. Doesn't everything have to go through the batteries first? Or can I power 12 V loads off of these terminals without using any batteries? (It's important that I am asking... I may have wired it wrong, thinking the load terminals is where the factory wires on my RV should go to, that go into the RV 12V panel from the batts.)

Have a Merry Christmas!
SolarSteve in Sebastian, FL.

BB.

Re: System Compatibility???

The load terminals are there for LVD (Low Voltage Disconnect)... If you have some small loads (typically around 10-15 amps maximum)--you can run them from these terminals. If the battery voltage drops below the programmed set point (typically 10.5 volts although this model may be programmable to 11.5 volts or other values--PDF Manual download)--The controller will shut down the load terminals.

A quick read through the manual also shows it has a high voltage disconnect function too (over 15.0 volts). If you have sensitive/expensive DC devices--using the Load Terminals is not the worst thing in the world.

In real life--15 amps is not a lot of current. And if you where to put something like a 300-600 watt inverter (around 35-70 amps maximum p, more for surge current)--it can damage the controller. Plus taking a battery bank to 10.5 volts (dead) is very hard on the battery bank and should be avoided.

Just connect everything directly to the battery bank instead (protected by appropriate fuses/breakers and disconnect switches).

-Bill

SolarSteve

Re: System Compatibility???

I started first playing with one of those Harbor Freight toy panels (15W) amorphous. It's only a couple more amps, but an amp is an amp!

1. Because my CC is up to, or very close to its 15A rating, I would need to hook this panel up separately with its own little CC directly to the battery bank if I wanted to bother using it? Correct? Is it that simple, or will other issues crop up?

Thanks!

BB.

Re: System Compatibility???

The MPPT type charge controllers control their output current--It will limit itself to 15 amps no matter what the input wattage is.

However, before you connect your amorphous panel--what is the Vmp of the array vs that of the Amorphous panel--Their Vmp's should be within ~10% of each other... The farther apart the voltages are--the more mismatch you have and the less efficiently the panel's true output wattage can be used.

Sort of like paralleling a 6 and 12 volt battery together... The lower voltage battery will not supply any useful power/current while the 12 volt one is outputting its current.

It is a bit more complex than that--if you want to get into the details of finding peak power points in the I*V curve (MPPT controllers are not designed to work with multiple power curve peaks and the panels cannot output optimum current/power if they are not reasonably matched in Vmp--for parallel connections; or Imp--for series connections).

-Bill

SolarSteve

Re: System Compatibility???

So to distill it down Bill...

Because I am using the main panels in series, and this single 15W panel is only about 15V, do not use it with the same battery bank??

BB.

Re: System Compatibility???

You would have have to connect the 15 watt panel (generally) through a second (small) charge controller to the battery bank. Did one come with the panel?

It is perfectly OK to connect multiple battery chargers to a single battery bank--Each controller will take care of its power source. Controllers will probably not coordinate transition from bulk to absorb to float--but that is really not going to matter. Each controller will make its own decisions.

Alternatively, connecting a small panel directly, through a blocking diode, to the battery bank would work OK too (if there are loads on the battery bank--not just floating). If there are no loads--it is possible a 15 watt panel would float the battery at too high of voltage and cause it to use excessive water.

-Bill

SolarSteve

Re: System Compatibility???

<<Did one come with the panel?>>
No, it did not come with a CC. I ended up with the panel like this... I walked into Harbor Freight with a coupon for a 5W panel for $29.99 which was supposed to be half off. I could not find the panel, so I asked the -manager- at the front when I was checking out other items. He looked at my coupon, and then came up to the front with the big, tall 15W panel and the clerk took the coupon and my $30. I said thank you. (;

Is it true that these amorphous panels actually charge quite well even in overcast conditions vs the others?

BB.

Re: System Compatibility???

I don't believe that Amorphous panels would perform any better under reduced sunlight than any crystalline type panel.

The two types of panel perform roughly the same... The differences:

1. Amorphous panels are generally less expensive and may not last as long as good quality crystalline panels.
2. Amorphous panels can lose ~20% of their output power in the first 6 months of sun. So, vendors typically rate their panels 20% lower to have similar warranty's (i.e., 80% after 10-20+ years). So, when first installed, amorphous panels can look very good--As their output may be 20-25% over "specifications"... But that extra power will disappear over the next few months.
3. Amorphous panels are less efficient vs mono/poly crystalline panels and need to be larger to collect the same amount of energy.
4. Amorphous panels are more sensitive to degradation due to water/oxygen leaks. For long life, Amorphous panels must be well constructed and sealed.

Anyway--that is what I have picked up from reading about the panels... Others may have other/different information.

-Bill "no expert" B.

stephendv

Re: System Compatibility???

BB. wrote: »

I don't believe that Amorphous panels would perform any better under reduced sunlight than any crystalline type panel.

I must pick you up on that one. Quite a few studies have shown that a-Si performs better under low irradiance than poli or mono, some links and extracts below:

http://www.solarfeeds.com/cleantech-applied/14371-the-bankability-of-thin-film-silicon- (Study by an a-SI vendor)
The most remarkable result was the comparison between thin film silicon modules and crystalline silicon modules. In both of the hot locations, Phoenix and Singapore, the thin film silicon panels produced >8 % more kWh per rated kWp than c-Si modules. Two notable trends explain the energy harvest advantage:

Less negative temperature coefficient which gives thin film silicon modules a performance advantage over c-Si modules at increasingly high irradiance and cell temperatures.
At low irradiance, the thin film silicon panels out-perform c-Si, due to a combination of spectral and angle-of-incidence effects.


http://cires.colorado.edu/science/groups/weatherhead/documents/200823EU4DO.9.3compareenergypvtech.pdf
The energy harvest of thin film solar plants is
essentially determined by the temperature behaviour and
(particularly for sites with a high percentage of overcast
sky conditions) by the sensitivity for low light levels,
which can be characterised by the dependence of fill
factor vs. irradiance. Angular effects and associated
spectral effects can be regarded as of second order.
Within the single thin film cell technologies there are
significant differences with respect to the characteristic
parameters. In general, CdTe and a-Si modules are less
temperature sensitive than CIS and crystalline silicon.
CdTe modules especially of the early production years
show an excessive efficiency under low light levels. CIS
and CdTe show a stable long time performance, for a-Si
seasonal variations have to be taken into account

Hong Kong electrical company chooses a-Si for their largest PV project partly because of low irradience performance in their tropical climate: http://www.aesieap0910.org/upload/File/PDF/4-Technical%20Sessions/TS27/TS2703/TS2703_FP.pdf

WEAK LIGHT PERFORMANCE AND SPECTRAL RESPONSE OF DIFFERENT SOLAR CELL TYPES: http://www.ecn.nl/docs/library/report/2005/rx05034.pdf
(To evaluate solar cells for indoor use for consumer devices) Figure 3 shows a nice graph comparing efficiency against light intensity.

russ

Re: System Compatibility???

Studies done by who?

If not by NREL or some party like that they may not mean much.

Russ

stephendv

Re: System Compatibility???

russ wrote: »

Studies done by who?

Authors are clearly stated in the linked pdfs. But it does require clicking on and then reading them.

SolarSteve

Re: System Compatibility???

Hello Bill or Others:

To make sure I understand this correctly... if I set my solar panels 25' feet from my RV to get total sun exposure, then for the wire length, I actually use 50' FIFTY feet for my voltage loss figure??

I found a guy with this cable: Submersible Pump Wire 10/3 with ground Romex type 10/4. I guess you had figured 8 gauge would be the best for the panels to the controller. If I use the above cable, and being a 4 conductor, if I wrap 2 wires together x 2, in other words, end up with two wires, would that be better than a 8/2?

Thanks!
SolarSteve

SolarSteve

Re: System Compatibility???

And remember Bill, we are going to wire the 2 panels in series.

niel

Re: System Compatibility???

i will confirm the a 25ft run of wire is a total of 50ft of wire due to 2 wires being present that the current needs to pass through.

2 #10 wires will yield an equivalent of #7 awg. this works if done in a non-critical application that the nec does not have say in as the nec would frown upon paralleling wires. i don't see a problem in your doing it as that single #10 wire is capable of carrying the power, but just not as efficiently as 2 will. the ability of that single wire to carry the load is one of the nec's arguments against paralleling as a break in one wire they say would stress and cause the other to fail, but not in your case.

BB.

Re: System Compatibility???

SolarSteve wrote: »

To make sure I understand this correctly... if I set my solar panels 25' feet from my RV to get total sun exposure, then for the wire length, I actually use 50' FIFTY feet for my voltage loss figure??

You are correct that there is 50' of wire for a 25' run... But voltage drop calculators are out there that use one way (25') or round trip (50'). Just depends on how the guy wrote the software (link I used asked for one way trip--i.e, 25').

I found a guy with this cable: Submersible Pump Wire 10/3 with ground Romex type 10/4. I guess you had figured 8 gauge would be the best for the panels to the controller. If I use the above cable, and being a 4 conductor, if I wrap 2 wires together x 2, in other words, end up with two wires, would that be better than a 8/2?

10 AWG was sort of the minimum requirement (to meet 3% maximum drop). 8 AWG was the next gauge calculation (usually wire goes in 2 awg steps).

Interestingly, if you double the wire cross section (and 1/2 the resistance), the way American Wire Gauge is defined, that is ~3 AWG steps.

So, if you parallel two 10 AWG wires, that is the equivalent of ~7 AWG (even better than 8 AWG).

Paralleling the cables are OK--just make sure you have solid connections at each end (you won't know if something came loose--you will get a bit of increased voltage drop--but everything will still work OK).

And a warning--while it is perfectly safe to parallel these two 10 AWG cables into a ~7 AWG equivalent--that is because we are only talking about 7 amps--perfectly safe for 10 AWG.

The warning is, say your 10 AWG wire is rated for 30 amps maximum. You do not want to parallel the two wires and expect it to be safe at 60 amps... Because current sharing is not always perfect--but also because if you broke one of the parallel connections, then the 60 amps is left for the other "good connection" which could overheat and melt the insulation/catch fire.

Lastly, is this cabling find strand (like an extension cord)? Or is it a few thick strands/solid cable?

If this is not a flexible cord--you will have problems with the connections remaining solid every time you roll up the cable to leave the site ("levering" out of connectors, work hardening copper to fracture, etc.).

-Bill

SolarSteve

Re: System Compatibility???

Thanks Guys, I really appreciate your continuing help with my first solar system!

One thing Bob... remember I will have -2- panels in series for 15A.

I can also use a piece of this same wire to go from CC to batts? Correct?

But then from the batts to the inverter is my next question. I ordered a Sunforce Pure Sine 1000W (got an open box for $169). Would 2/0 be correct for a 4' each way run?

And finally what fuses and where should I put them?

Thanks again!
SolarSteve

SolarSteve

Re: System Compatibility???

Guys... my last message did not show up. Replies are greatly appreciated! Have a great weekend everybody!!!
SolarSteve

SolarSteve

Re: System Compatibility???

One other question fellows...

I'm trying to make due with what I have laying around now that my wife has found out I'm in over a grand in the solar for the RV. Oh boy!!?? Ain't it great being married?? (:

I know some circuit protection. I have a couple of the old fashioned tube fuse holders. Where should I install these and with what amperage fuses?

I also have 1 Blue Seas 15A circuit breaker. I think this was from an AC panel in one of my boats, but is a breaker a breaker AC or DC? 2 terminals on the bottom. Remember I have a 15A system with the 2 panels.

AA1-X0-09-711-X11-P
FL. Amp (In) 15
Max v. (Ue) 65 250
Freq. DC 50/60
Delay 34
Trip Amps 20.25
Circuit 80
Icn 3000A
9385
Mexico 0350

niel

Re: System Compatibility???

i'm not bob, but i can throw my 2 cents in.:-)

I can also use a piece of this same wire to go from CC to batts? Correct?
yes, if it is short as you want the v drop to stay under 1% here.

Would 2/0 be correct for a 4' each way run?
that will work just fine i think.

And finally what fuses and where should I put them?
depends as there should be fuses on every lead to or from a battery and it's also good to fuse the pv leads to the controller, but place them in an accessible place for you don't want to replace one at the pvs especially if inclimate weather is around.
usually the fuse is specified in the pv specs for one or more pvs that are either a single pv or a series of pvs where voltages add.
the fuse between the controller and the battery should be near the battery and would minimally be the value you have on the pvs, but could go as high as the rating of the controller ampacity. many opt for the controller ampacity rating.
if the inverter does not specify a fuse rating then figure full power of 1000w/10.5v (bottom end voltage for most inverters) to get a current rating of 95.28a. i believe the nec makes you up that by 25% so 1.25 x 95.28 = 119.05a. the next highest commercial value is 125a. this must be a dc rated fuse or cb at the voltage of intended use. this will also be placed near the battery.

.....,but is a breaker a breaker AC or DC?
breakers must be rated for dc and at the voltage of use as i stated. this "Freq. DC 50/60" tends to look like it may be dc rated, but it may be advisable to check with blue sea to see what they say about their cb.

SolarSteve

Re: System Compatibility???

Thanks Neil.

I feel like a dunce again for having to ask this, but I don't what to damage anything. This is my first time with solar.

I had the 2 panels wired in parallel for starters which worked fine and was easy. +to+, -to- and then the charge controller got wired to the INSIDE CONNECTIONS +and- of one of the panels. I guess the next row in on these panels gives you the blocking diodes, etc.

Now I want to SERIES wire up the optimum setup because I have an MPPT controller. This is the best setup according to the Morningstar String Calculator, that I wire the 2 panels in series. (I will watch out for shading).

So I ran a wire from the negative of one panel to the positive of the other. I know if this were batteries, I would just run a lead back from the positive of one, and the negative of the other. BUT... I have the -charge controller- to contend with!!?? (That was wired to the screws of "one row in" on one panel before).

HOW DO I WIRE THIS ALL CORRECTLY??? THANKS!!

mike95490

System Compatibility???

I'll try this in ASCII

I'll list panel 1 first, it's + - term, then the place that terminal connets to
then panel 2
hope it helps

panel 1:
+ to the charge controller PV input +
- to panel 2 + terminal

panel 2
+ (already ties to panel 1 - )
- to the charge controller PV input -

Good luck

I assume you are sure the panels fall within the MPPT aloweed range.

Generally you connect the controller to a fully charged battery bank FIRST, then connect the PV to the controller. Some controllers need jumpers or switches set, some auto detect everything.

Your mileage may vary

mike-please note i moved your reply here into this thread as he asked it in this thread too.

niel

Re: System Compatibility???

steve,
don't over complicate this or get yourself all confused. the plus of pv1 of the series goes to the pv+ input on the controller and hopefully you'll have a fuse on this lead. the minus of pv2 goes to the pv- input on the controller.

it should go the pv+ input on the controller to the plus of pv1. (with a fuse inserted inline here.)
pv1's minus goes to pv2's plus.
pv2's minus then goes to the pv- input on the controller.

SolarSteve

Re: System Compatibility???

Thank you both for your replies. I just want to make sure I do this right.

There is a u-tube video showing the terminal boxes on the panels, located by searching Utube for "Sunforce 39126 246-Watt"

Web is http://www.youtube.com/watch?v=wFh_x8DTAjk

There are FIVE connections in the terminal box. A plus and a minus on each end, and then the 3 in the middle that go down to potted electronics (diodes?). With the parallel setup, I was required to hook the charge controller to ONE TERMINAL IN FROM THE REGULAR PLUS AND MINUS on each end of one panel.

I am still confused. I have done the minus to plus between the 2 panels. Please take a quick look at the terminal box in the video and let me know exactly where the rest of the wires should go.

Thank you so much!

SolarSteve

Re: System Compatibility???

SIX TERMINALS, sorry.