question

tomf72 avatar image
tomf72 asked

Solar Panel - appropriate MPPT

Hello - My name is Thomas and I am planning to built a small electricity backup system for our house.

I have just bought a 200AH Lifepo4 battery (12v) and I am planning to purchase a solar panel from Jinko (Jinko Pro 460W -> max power). This panel has a voltage of 33.7v (open circuit 41v) and power current of 13A (short circuit current) 13.7A.

My plan was to purchase a victron MPPT 100/20.

As far as I understand this combination should work. Could someone pls confirm that my assumption is correct.

Many thanks in advance.

Solar Panel
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @TomF72

The 100/20 will 'work', but it's not enough to use the full capacity of the panel. For simplicity, let's use 14V as a charge V. 20A x 14V = 280W. A 100/30 would do 420W, which is a more practical level for typical solar days. Or you could even go bigger.

There's a mppt calculator on the Victron website if you want to check what it says. In the washup, it's your decision to choose how much power you actually need from it.

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gyzko avatar image
gyzko answered ·

You can use the excel spreadsheet provided by Victron to confirm your plan. You can modify it and add your solar panel as it looks like you have the spec (Vmp, Voc, Imp, Isc). Do not forget about temperature.

https://www.victronenergy.com/upload/software/VE-MPPT-Calc-4_0.xlsm

If everything is "green", you have your answer.

-François

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