Recommend Solar Panel or Panels

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x7razor

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Hi asking for friend since I have no experience with solar and my input might be wrong :ROFL:. So want to make sure from the experts before I tell him something. (I was thinking 4 x 100w Panels in parallel to get closer to the max charging amps of battery and not over the 400w limit of inverter I do not even know if you need to be exactly on the limit or under I don't know jack). This is just powering a 50" tv, sound bar, LED light or 2.

Sun 12v 1500 watt Pure sine wave Hybrid
Max PV Power = 400W
Max PV VOC = 50VDC
PWM Input Voltage Range 15-50VDC
Best Vmp Range: 15-20VDC
Max PV Voltage 50VDC
Max PV Charging Current = 30A

Battery Tobo 12v 1.28kwh 100Ah LiFePO4
Max Charging Voltage = 14.6
Max Charging Current = 20A
 
You don't need to get so many small panels

But yea you are correct you want the voltage to fall in that best vmp range of between 15-20v vmp , you will get the same effect if you have one higher watt panel that has the same voltage as the 100w panel

ie you have to search for 30cell panels which would be a voc a bit over 20v panels if you can't get a high wattage panel with that voltage them yes you can go parralel

I suppose the charge rate of the battery is by choice , on lithium you can happily charge it at 30A of the charge controller if the bms supports it

Going higher voltage see you deal better with bad weather but lose more output though

ie lets say you have a panel that is 200w 11.1A at 18v it will give you at working voltage of battery 11x13.5v 148.5 charging watts peak

While if you have a 300w 30v panel that is 10A

You will get at 13.5v x 10A = 135w
 
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You can also go a touch over the max wattage but not the voltage

And since you lose a lot of output because of the way pwm controllers work you can size your panels around what output you will get at battery voltage

ie i think you would need a bit over 500w of panels to actually get about 400w at the battery voltage
 
leon.davibe said:
You don't need to get so many small panels

But yea in a way you are correct you want the voltage to fall in that best vmp range of between 15-20v vmp , you will get the same effect if you have one higher watt panel that has the same voltage as the 100w panel

ie you have to search for 30cell panels which would be a voc a bit over 20v panels if you can't get a high wattage panel with that voltage them yes you can go parralel

I suppose the charge rate of the battery is by choice , on lithium you can happily charge it at 30A of the charge controller if the bms supports it

Going higher voltage see you deal better with bad weather but lose more output though

ie lets say you have a panel that is 200w 11.1A at 18v it will give you at working voltage of battery 11x13.5v 148.5 charging watts peak

While if you have a 300w 30v panel that is 10A

You will get at 13.5v x 10A = 135w
Click to expand...
Specs for the 100W panels:
1688752016565.png
 
Yea the panel specs are perfect

Was just thinking if you can get a bigger wattage panel you can use less mounting hardware. But yea options are few when it comes to lower voltage panels

So in the end it depends what you can get as long as you stay well clear of the 50v max Try and use under 36v. it is a trade of, if you go higher you get better bad weather production

And in perfect conditions you just get way less than panel rating due to bigger voltage drop
In the end availability may make the choice on your behalf

Think i had the cell count out what you find easier is the 36cell count panels that you selected
 
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Buy a single 300w panel, or 2. Wire them up in parallel. Sorted.

300w is usually 36v / 8.36a. Check panel specs before you buy.

Forget about 100w panels.

(didn't see it was PWM, yeah, then go for 100W panels, you need to feed in more amps at the voltage, not more volts.)



1 panel would be 36v / 8.36a - well under your 50v DC even at VoC.
2 panels in parallel would be 36v/16.72a - well under your 50v DC and 30A max.


----

If you can't find 300W panels (they'll be old stock).

1 x Canadian Solar 365W Super High Power Mono PERC HiKU All Black with MC4-EVO2

33.9v / 10.78A (40.6V VOC). so still under your 50V max on the inverter.
Should be around R2300 or so for the panel.
 
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leon.davibe said:
Yea the panel specs are perfect

Was just thinking if you can get a bigger wattage panel you can use less mounting hardware. But yea options are few when it comes to lower voltage panels

So in the end it depends what you can get as long as you stay well clear of the 50v max Try and use under 36v. it is a trade of, if you go higher you get better bad weather production

And in perfect conditions you just get way less than panel rating due to bigger voltage drop
In the end availability may make the choice on your behalf

Think i had the cell count out what you find easier is the 36cell count panels that you selected
Click to expand...
How do you get a bigger wattage panel with a lower voltage?
 
itareanlnotani said:
Buy a single 300w panel, or 2. Wire them up in parallel. Sorted.

300w is usually 36v / 8.36a. Check panel specs before you buy.

Forget about 100w panels.



1 panel would be 36v / 8.36a - well under your 50v DC even at VoC.
2 panels in parallel would be 36v/16.72a - well under your 50v DC and 30A max.


----

If you can't find 300W panels (they'll be old stock).

1 x Canadian Solar 365W Super High Power Mono PERC HiKU All Black with MC4-EVO2

33.9v / 10.78A (40.6V VOC). so still under your 50V max on the inverter.
Should be around R2300 or so for the panel.
Click to expand...
PWM charger charging 12V battery. What happens to the 36V?
 
wingnut771 said:
PWM charger charging 12V battery. What happens to the 36V?
Click to expand...
Ah ****, you're absolutely. right, I didn't see it was PWM, I only looked at the voltages.

PWM Input Voltage Range 15-50VDC
Best Vmp Range: 15-20VDC
Max PV Voltage 50VDC
Max PV Charging Current = 30A

---


Ok, then the 100W panels are better, as he needs lower voltage, more amps.
 
wingnut771 said:
How do you get a bigger wattage panel with a lower voltage?
Click to expand...
Cell count

ie like the 670w canadian that is 45v lower than some 450w panels

Because it is 66 cell not 72

So you have a bigger cell that gives more amps

Voltage is cell count related
Watts is cell size related
 
leon.davibe said:
Cell count

ie like the 670w canadian that is 45v lower than some 450w panels

Because it is 66 cell not 72

So you have a bigger cell that gives more amps

Voltage is cell count related
Watts is cell size related
Click to expand...
Do you have any links for 200W 20V panels?
 
wingnut771 said:
Do you have any links for 200W 20V panels?
Click to expand...
The listing details is dubious
So not sure if it is what it says it is

The vmp is under 20v

It states 60 cells, it may be in a 30/30 config ie like a half cut that is 144 cells arranged as 72/72

solarwarehousesa.com

Ecco 200w Mono Solar Panel

Ecco 200w Mono Solar Panel (Courier for panels are at your own risk) Description: -Peak Power(Pmax) 200w-Peak Voltage(Vmpp) 17.4V-Peak Current(Impp) 11.49A-Short Circuit Current (ISC) 12.30A-Open Circuit Voltage(Voc) 21.6V-Max System Voltage 715V- Size: 1640 x 992 x 35- Length of cables 1m Cable...
solarwarehousesa.com solarwarehousesa.com

Bit higher voltage 250w 30v

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160w 22.7v

www.firstshop.co.za

Mecer 160W Solar Panel IE160-160WP

Mecer 160W Solar Panel IE160-160WP and other Mecer products available at FirstShop South-Africa. Price, availability and reviews for Mecer IE160-160WP
www.firstshop.co.za www.firstshop.co.za

Vs this funny high voltage module 180watt 45v just for interest sake

 
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