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Mix 24V and 12V solar panels on single MPPT

DurkaDurka

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Joined
Jun 7, 2022
Messages
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I have four 12V 100 watt panels in series working just fine. I have a potential deal to get two 24V 200 watt new panels for cheap. Specs for both :

CURRENT panels
Maximum Power: 100
Open-Circuit Voltage (Voc): 21.6
Short-Circuit Current (Isc): 6.5
Optimum Operating Voltage (Vmp): 18
Optimum Operating Current (Imp): 5.56
Maximum Series Fuse Rating: 15

NEW panels
Maximum Power(Pmax): 200
Open Circuit Voltage(Voc): 45.4
Short Circuit Current(Isc): 5.83
Maximum Power Voltage(Vmp): 37.6
Maximum Power Current(Imp): 5.32
Maximum Series Fuse Rating: 15

All attached to a Victron 100/50. I am running a 12V battery (may shift to 24V later), so the system will top out at 700 watts per manual. That's fine by me as the current setup tops out at about 350 watts, so over-paneling may work.

Based on the specs, it looks efficient to put the two 200 watt panels in series and parallel them to the four 100 watt panels already in series. This should run them all at the appropriate voltages. Can you fine folks please confirm?
 
Not a perfect match. But probably close enough to not suffer major losses.
 
I have four 12V 100 watt panels in series working just fine. I have a potential deal to get two 24V 200 watt new panels for cheap. Specs for both :

CURRENT panels
Maximum Power:
Open-Circuit Voltage (Voc): 21.6
Short-Circuit Current (Isc): 6.5
Optimum Operating Voltage (Vmp): 18
Optimum Operating Current (Imp): 5.56
Maximum Series Fuse Rating: 15

NEW panels
Maximum Power(Pmax): 200
Open Circuit Voltage(Voc): 45.4
Short Circuit Current(Isc): 5.83
Maximum Power Voltage(Vmp): 37.6
Maximum Power Current(Imp): 5.32
Maximum Series Fuse Rating: 15

All attached to a Victron 100/50. I am running a 12V battery (may shift to 24V later), so the system will top out at 700 watts per manual. That's fine by me as the current setup tops out at about 350 watts, so over-paneling may work.

Based on the specs, it looks efficient to put the two 200 watt panels in series and parallel them to the four 100 watt panels already in series. This should run them all at the appropriate voltages. Can you fine folks please confirm?


I would make it symmetrical. Parallel One 200 and Two x 100 in series.

The way they rate these things and 2 different brands, and it looks like the 4x100 and 2x200 add up to different total voltages.

Anyone else agree on the symmetrical thing ?
 
Last edited:
I would make it symmetrical. Parallel One 200 and Two x 100 in series.

The way they rate these things and 2 different brands, and it looks like the 4x100 and 2x200 add up to different total voltages.

Anyone else agree on the symmetrical thing ?

Thanks for the reply, but that deal long passed. I'm going to get another 4 x 100 identical panels and eventually put them on a shed I'm making. No issues anymore. :)
 
Any chance you can place the second array different facing? Maximize your total KWhr over the entire day vs a shorter peak value if they are all pointed same direction.
 
Any chance you can place the second array different facing? Maximize your total KWhr over the entire day vs a shorter peak value if they are all pointed same direction.

I have little choice here as it's going on a lean-to style shed roof (66" x 96"). It'll be in one direction and I'll have to live with it. At least it's about 9' high so I can mostly avoid shading from my neighbors house/chimney. Hoping I can get a clean 3-4 hours of solar.
 
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