Rich Solar panels..?

[Electrodude9]

Yes, as Steelhead alluded, running all 4 in series will get your array voltage up towards the MPPT sweetspot.

I'll try that! Not a problem, just need to switch around a few connections.

I've got 8 gauge wires from the CC to the panels so that can handle high(er) amperages and/or higher voltages without any problem, for the length that I'm running.

 

[Electrodude9]

Yes, as Steelhead alluded, running all 4 in series will get your array voltage up towards the MPPT sweetspot.

So, I could (and should? ?) get some more panels in order to "max out" my voltage up closer to the 145 limit for the CC for best recharging/"maintenance of SOC" of my battery bank?

 

[MisterSandals]

So, I could (and should? ?) get some more panels in order to "max out" my voltage up closer to the 145 limit for the CC for best recharging/"maintenance of SOC" of my battery bank?

The specs that you attached show the MPPT range is 30-80v so I think having the Voc at 88 and the Vmp (operating voltage) just below 74.4v is optimal.

 

[Hedges]

They're not located in thier final location yet, so they do get some tree branch shadows on them quite often throughout the day. I suppose that's what's putting the kibosh on any significant production?? That, and the fact that it's winter sun?

Oh yeah, bit of shade will do it for sure.

What percentage of a single cell has shade? 90%, so only 10% of one cell is getting sun? If so, current from that cell is only 10%, and current from entire panel and string is only 10%.

With sufficiently long series string, it is possible for the other panels (or diode-bypassed portions of this panel) to push their current past the partially shaded diode-bypassed portion. But if there is some light on each cell of the partially shaded portion, MPPT controller may stop at a higher voltage power peak with that 10% of current, and miss a lower voltage peak (75% of voltage) with 100% of current.

Various shading situations aren't always handled well by charge controllers.
You need to see how your array performs in full sun, no partial shading.

 

[Electrodude9]

The specs that you attached show the MPPT range is 30-80v so I think having the Voc at 88 and the Vmp (operating voltage) just below 74.4v is optimal.

I switched to all four panels being in one single series and it improved performance a LOT! Even though the panels are in the same temporary place, pointing in the same direction, right now. Voltage listed on the MPP Solar CC green readout screen gets up to the 70s.

If I understand correctly, I could fire up four more panels in series and then connect the existing 4-panel and the new 4-panel groups in parallel for perfect 800 watt PV partner for my MPP Solar CC and 24v 92 Ah battery. That would maintain the "optimal" voltage you mention above. Though amps would double that would still keep the amps under 12, right? And my 8 gauge wires can handle that for this install; and the MPP can too. (It's rated for up to 80A, I believe).

 

[MisterSandals]

I could fire up four more panels in series

No the Voc is too high for that. Maybe 3, do the math. On phone cannot see everything.
Keep total under input voltage max. Allow 10% for cold weather voltage increase.
If you have mppt range, stay inside that for Vmp.

 

[Electrodude9]

Oh yeah, bit of shade will do it for sure.

What percentage of a single cell has shade? 90%, so only 10% of one cell is getting sun? If so, current from that cell is only 10%, and current from entire panel and string is only 10%.

With sufficiently long series string, it is possible for the other panels (or diode-bypassed portions of this panel) to push their current past the partially shaded diode-bypassed portion. But if there is some light on each cell of the partially shaded portion, MPPT controller may stop at a higher voltage power peak with that 10% of current, and miss a lower voltage peak (75% of voltage) with 100% of current.

Various shading situations aren't always handled well by charge controllers.
You need to see how your array performs in full sun, no partial shading.

Hedges,

Thanks for responding. The percentages of shade on the various modules (panels) varies from time to time and throughout the day. Sometimes a single panel can experience up to 25% shading if a big branch is in the way at that time. These panels DO feature diode-bypass which can only help, I understand - so that's good, at least.

Looking forward to testing my setup in full sun, no partial shading!

 

[Electrodude9]

No the Voc is too high for that. Maybe 3, do the math. On phone cannot see everything.
Keep total under input voltage max. Allow 10% for cold weather voltage increase.
If you have mppt range, stay inside that for Vmp.

I think I understand where you're coming from... I shan't hook up 7 or 8, or even 6 panels in a single string in series because, yes, that could or would exceed my voltage "intake" that the charge controller can handle. But I could have two series strings operating at 88v each then tied together in parallel, correct? Or am I dense?

Sorry, still kind of new at this. Actually looking for a good in-depth solar book or such. I have read a few 'beginner' versions.

 

[Hedges]

I think I understand where you're coming from... I shan't hook up 7 or 8, or even 6 panels in a single string in series because, yes, that could or would exceed my voltage "intake" that the charge controller can handle. But I could have two series strings operating at 88v each then tied together in parallel, correct? Or am I dense?

Sorry, still kind of new at this. Actually looking for a good in-depth solar book or such. I have read a few 'beginner' versions.

If panels are 22Voc, connecting 8 panels as 4s2p would be 88Voc at 25 degrees C. Might reach 100V or so somewhere below freezing.
If your charge controller is rated 145V max (2424LV-MSD) then it is no problem.
If it is rated 102V (1012LV-MS) then it depends on your location and exact temperature coefficient of panels.

 

[MisterSandals]

But I could have two series strings operating at 88v each then tied together in parallel, correct?

That looks correct.

Sorry, still kind of new at this. Actually looking for a good in-depth solar book or such. I have read a few 'beginner' versions.

Have you looked on the sister-site? Look under the "more..." menu for the videos which are very good.

Mobile Solar Power: Made Easy! DIY Off-grid Solar Power!

Building a vehicle mounted solar power system? Let me help.

www.mobile-solarpower.com

 

[Electrodude9]

If panels are 22Voc, connecting 8 panels as 4s2p would be 88Voc at 25 degrees C. Might reach 100V or so somewhere below freezing.
If your charge controller is rated 145V max (2424LV-MSD) then it is no problem.
If it is rated 102V (1012LV-MS) then it depends on your location and exact temperature coefficient of panels.

I bought the 2424-MSD, so it'll be no problem! :D