Series vs parallel panel connection on outback fm80

[Mahendra Gomanie]

I am trying to figureout if I missed any knowledge on mppt charge controllers and solar panels.

The system is 12v off grid .All items mentioned are on hand .It’s just a question of the 10-60w panel configuration.

I have 10 60w bp solar panels with the following specs

STC Power Rating Pmp (W)	60
Open Circuit Voltage Voc (V)	21.0
Short Circuit Current Isc (A)	3.87
Voltage at Maximim Power Vmp (V)	16.8
Current at Maximim Power Imp (A)	3.56
Panel Efficiency	10.8%
Fill Factor	73.8%
Power Tolerance	-3.00% ~ 3.00%
Maximum System Voltage Vmax (V)	600

My thought are to put these in two series strings of 5 to save on wire breakers ease of installation etc.

I friend of mine however ,advised against series strings and suggested that 5 parallel strings of two in parallel(basically 10strings on 5breakers) should be done basing his ideas that each panel would not be protected by breakers and that there would be losses due to the series configuration.

I honestly do not see much merit in this .Please share your thoughts.Are the losses due to series strings justifiable?

 

[Mjs]

You have it right. 2 parallel strings of 5 panels in series. Only one 10-amp PV breaker needed.

 

[RV8R]

Post the performance specs of your solar charger & we can give you better informed opinions.

Battery specs would help also.


I have a Victron 100 | 50 & 6 - 100W panels 3S2P so that gives me about 60V & 10A. Seems to work well for me. It is weather dependent & equipment dependent.

 

[Mahendra Gomanie]

Sorry though I posted that charge controller is an Outback fm80mpg 150v max 80a output.
battery is four rolls 200ah arm.
the system has Xantrex C60 as well with similar panels

 

[RV8R]

Sorry though I posted that charge controller is an Outback fm80mpg 150v max 80a output.
battery is four rolls 200ah arm.
the system has Xantrex C60 as well with similar panels

I am not familiar with that equipment. However if the equipment can take it & the weather / environment gives you good sunlight I like your 5S2P idea ,,, giving you about 84V @ 7.1A for a total of 596W.

If that works for your equipment.

Depending on wire cost, sometimes it is better to size the wire for other possible options “more amps” or changes in the system. If the costs / distances are minimal I would go bigger size wire to provide options. Those are hard design decisions when we don’t know what the future will hold for changes in our systems down the road.