Solar Panel Wiring

[97435207]

Hello i am very new to this forum so i hope i have placed this thread in the right place

These are my 3 solar panels :
1.
Peak power: 30W
Maximum power voltage (Vmp): 17.5V
Maximum power current (Imp): 1.71A
Open circuit voltage (Voc): 21.6V
Short circuit current (Isc): 1.85A
2.
Peak power: 100W
Maximum Power Voltage (Vmp):19.3V
Maximum Power Current (Imp): 5.18A
Open Circuit Voltage (Voc): 22.9V
Short Circuit Current (Isc): 5.56A
3.
Peak power: 250W
Maximum Power Voltage (Vmp) :30.6V
Maximum Power Current (Imp) : 8.17A
Open Circuit Voltage (Voc) : 36.3V
Short Circuit Current (Isc) : 8.17A

And my question is i need to find a way to wire them all together into one 20A mppt charge controller with the voltage going into the charge controller being 24v or 12v without losing much power.

Just in case its a 12v battery bank.

Thanks for any infomation.

[ButchDeal]

Hello i am very new to this forum so i hope i have placed this thread in the right place


And my question is i need to find a way to wire them all together into one 20A mppt charge controller with the voltage going into the charge controller being 24v or 12v without losing much power.

Just in case its a 12v battery bank.

Thanks for any infomation.

What Charge controller do you have? it would be strange that the power on the input side would need to be limited to 12/24V. That is likely the battery side.

[97435207]

What Charge controller do you have? it would be strange that the power on the input side would need to be limited to 12/24V. That is likely the battery side.

Thank for the quick reply ButchDeal

You can find the charge controller on ebay here the item number:
141211127381 (you can type this in on ebay)

[97435207]

What Charge controller do you have? it would be strange that the power on the input side would need to be limited to 12/24V. That is likely the battery side.

Thank for the quick reply ButchDeal

You can find the charge controller on ebay herei s the item number:
141211127381 (you can type this in on ebay)

[ButchDeal]

Thank for the quick reply ButchDeal

You can find the charge controller on ebay herei s the item number:
141211127381 (you can type this in on ebay)

so you have different specs based on the battery voltage. if you are charging a 12V battery then you can only attache 275W of solar, if 24V then you can attache 550W of solar.

if 12V battery bank then you can only attache the one 250W module.

[sensij]

There is something wrong with your 250 W specs, Isc can not equal Imp.

There is no charge controller that will take all three of those panels and combine them perfectly. The best you can do, if you upgrade to a 30 A charge controller, is put the 100 W and 30 W panels in parallel to create an ~18 V ~6.9 A circuit, and put that in series with the 250 W panel for something like a combined ~6.9 A @ ~49 V, but even that is kind of sketchy.

[97435207]

so you have different specs based on the battery voltage. if you are charging a 12V battery then you can only attache 275W of solar, if 24V then you can attache 550W of solar.

if 12V battery bank then you can only attache the one 250W module.

Ok that does make alot of sence so i would have to go with a 30Amp controller

[97435207]

There is something wrong with your 250 W specs, Isc can not equal Imp.

There is no charge controller that will take all three of those panels and combine them perfectly. The best you can do , if you upgrade to a 30 A charge controller, is put the 100 W and 30 W panels in parallel to create an ~18 V ~6.9 A circuit, and put that in series with the 250 W panel for something like a combined ~6.9 A @ ~49 V, but even that is kind of sketchy.

Strange the Isc and Imp do match what the back of the panel and website says. With the method of wiring your suggesting would you know how much power i would lose?

[sensij]

Strange the Isc and Imp do match what the back of the panel and website says. With the method of wiring your suggesting would you know how much power i would lose?

What website for the panel?

It depends a little bit on how the charge controller works. Based on the numbers I guessed (just a guess!), 6.9 * 49 = 338 W, from a (250 + 100 + 30) = 380 W system, so 11% loss. My guess might be a bit high, the loss will probably be a little bit worse.

[97435207]

What website for the panel?
It depends a little bit on how the charge controller works. Based on the numbers I guessed (just a guess!), 6.9 * 49 = 338 W, from a (250 + 100 + 30) = 380 W system, so 11% loss. My guess might be a bit high, the loss will probably be a little bit worse.

Ok here is the item number on ebay for panel:161469136314

Could i have the two 12v panels in series then parallel it with the 24v?

Also would it be more efficient if i just wired the 100W and The 250W not the 30W

[sensij]

Ok here is the item number on ebay for panel:161469136314

Could i have the two 12v panels in series then parallel it with the 24v?

Also would it be more efficient if i just wired the 100W and The 250W not the 30W

Since the Vmp * Imp = panel wattage, the Isc is probably the incorrect value. Bad sign when all of the distributors have the same info, and the mfg doesn't even have specs on their page.

Yes, two 12 V panels in series will usually parallel OK with a 24 V panel. However, your 250 W panel isn't a 24 V panel... it is a 20 V grid-tie panel. A 24 V would have a Voc over 40 V, and a Vmp of around 35 V.

The 100 W and 250 W will probably be worse than the (100 W + 30 W) with the 250 W. The panels you have just aren't made to work together.

[97435207]

Hello again, i just had an idea i wanted your opinion on could get a step down module to take the solar panel voltage to 12v i know it is not extremely efficient but would it work??