question

Andreas Nicolet avatar image

144-cell 350W panel in 12V system with 75/15 MPPT controller?

Hello,

I have purchased a 75/15 MPPT Victron charge controller and I am wondering if I can safely attach this 350W-rated solar panel (See below).

The system is connected to a 12V battery.

I have plenty of buffer in my calculations in terms of power and energy needs, so I don't mind if I "peak shave" the solar production curve a bit if that is the case. I just need to know (rule of thumb'ish) how bad it would be, and whether it would be safe.

Please can you help? I'd rather not have to return the unit and buy another controller.

Thanks a bunch!

Solar specs:

DC Electrical Characteristics

  • STC Power Rating 350W
  • PTC Power Rating 323.85W 1
  • STC Power per unit of area 174.4W/m2 (16.2W/ft2)
  • Peak Efficiency 17.44%
  • Power Tolerances 0%/+2%
  • Number of Cells 144
  • Nominal Voltage not applicable
  • Imp 9.11A
  • Vmp 38.43V
  • Isc 9.58A
  • Voc 46.27V
  • Series Fuse Rating 20A
  • Maximum System Voltage 1000V
MPPT Controllerssolar sizing
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1 Answer
seb71 avatar image
seb71 answered ·

Just one PV panel, I assume.


Voc 46.27V is well below the 75V limit of the 75/15 solar charger, so from this point of view it is safe.


Isc is less of an issue, but anyway Isc 9.58A is also safe for sure for your 75/15 SmartSolar charger.


The 75/15 charger has a maximum 15A to the battery (and/or loads). Used in a 12V system (12V battery), this means the maximum power it can output is about 210-220W.


Your 350W PV panel will be limited at that value in good weather, so it seems like a waste, but during cloudy days (when the PV power can easily drop to 10% of the maximum power) you will be glad to have a larger panel.

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