24 volt series adding 1 200 watt 12volt panel

freeflow

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Hi
I got a 24-volt mppt hybrid inverter which is currently supplied by 2 * 320 watt series 12 volt panels, eg 24 volt, and i like to just boost the amps and place an additional 200 watt panel in a different position to get more of the morning sun. My question is, is it ok to just ad a 12volt 200-watt panel to this system or do they all have to be 24 volts? the mppt can handle the open voltage and amp input.
Thanks
 

Bud Martin

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What are the full spec.of the 320W and 200W panels?
I doubt that the 320W is the so called '12V'.
 

freeflow

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This one is the series "320" watt it says 380w but I ordered 320w lol I got 2 in series
panel specs.jpg
This is what I want to add as stand-alone 200watt
  • Max Current (Imp) 10.8A
  • Maxes Voltage (Vpm) 19.5V
  • Short Circuit Current (Isc) 11.5A
  • Open Circuit Voltage (Voc) 23.6V
 

12VoltInstalls

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is it ok to just ad a 12volt 200-watt panel to this system or do they all have to be 24 volts
The VOC depending on panel is likely between 18 and 24VDC and will not contribute to 24V charging. That’s the basic assumptive answer.

But the panel specs will inform the question.
EDIT:
as stand-alone 200watt
  • Max Current (Imp) 10.8A
  • Maxes Voltage (Vpm) 19.5V
  • Short Circuit Current (Isc) 11.5A
  • Open Circuit Voltage (Voc) 23.6V
This what I meant. Need two in series to achieve 24V charging.
 

freeflow

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The VOC depending on panel is likely between 18 and 24VDC and will not contribute to 24V charging. That’s the basic assumptive answer.

But the panel specs will inform the question.
EDIT:

This what I meant. Need two in series to achieve 24V charging.
So it does not matter I already got 2 in series achieving the charging and just want to up the amperage?
 

timselectric

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So it does not matter I already got 2 in series achieving the charging and just want to up the amperage?
Adding one panel in parallel with the two in series won't do any good.
In fact it will make it worse, by pulling the voltage down too low to charge batteries.
You need to add two panels in series facing the new direction in parallel with the first two panels.
2s2p
 

freeflow

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Adding one panel in parallel with the two in series won't do any good.
In fact it will make it worse, by pulling the voltage down too low to charge batteries.
You need to add two panels in series facing the new direction in parallel with the first two panels.
2s2p
thanks sometimes can not see the wood for the trees...so best do 2 x 100 watts in series and then in parallel
 

timselectric

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thanks sometimes can not see the wood for the trees...so best do 2 x 100 watts in series and then in parallel
100 watts?
No
The two strings should be very close in voltage and amperage. The output voltage from the combined strings will be pulled down to the lower string.
 

HRTKD

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Hi
I got a 24-volt mppt hybrid inverter which is currently supplied by 2 * 320 watt series 12 volt panels, eg 24 volt, and i like to just boost the amps and place an additional 200 watt panel in a different position to get more of the morning sun. My question is, is it ok to just ad a 12volt 200-watt panel to this system or do they all have to be 24 volts? the mppt can handle the open voltage and amp input.
Thanks

See this blog post for details on adding mismatched panels to an existing system.

 

freeflow

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Then there’s that. Get a P30L pwm and run the 100W on that. Or for nearly the same moula an Epever 10A mppt
Could i then connect the output from the second mppt to the existing solar panel string in parallel and then connect the total to the PV input of the inverter instead of direct of connecting to the battery?
 

12VoltInstalls

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Could i then connect the output from the second mppt to the existing solar panel string in parallel and then connect the total to the PV input of the inverter instead of direct of connecting to the battery?
You ‘could’ but why?! It’s not a good idea for a laundry list of reasons.
Just use the second charge controller to do what it is designed to do, charge the battery(batteries).
 

timselectric

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Could i then connect the output from the second mppt to the existing solar panel string in parallel and then connect the total to the PV input of the inverter instead of direct of connecting to the battery?
That would be even worse than connecting the single panel to the other two. Because the voltage would be even lower.
 
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