weslleyphinverter avatar image
weslleyphinverter asked

What's the MPPT should I use with a MULTIPLUS-II 48/3000 120V ?

Hi there

I am new about Victron, but I will buy the MULTIPLUS-II 48/3000/35-50 120V + a unit Cerbo GX

So, I don't have any Idea about MPPT.

What type and model of MPPT should I pick?

In my scenario will set:

6 X 550 Watts solar panel

4 X battery 12V 220 A connected by series, total: 48V 220A.


Multiplus-IIMPPT ControllersMPPT SmartSolar
2 |3000

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2 Answers
Alexandra avatar image
Alexandra answered ·

The answer more depends on what panels you have and what their VOC is among other details are.

Use the online calculator and put your solar panels details into it and it will recommend one for you.

If you want a sanity check after using it. Post your solar panel details and we can help you check the maths and config

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weslleyphinverter avatar image
weslleyphinverter answered ·


I have two option about solar panel:

1) Jinko



2) Ja solar

JAM72S30-550/MR 550W


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kevgermany avatar image kevgermany ♦♦ commented ·

It's not just the panels, but how you connect them.

Couple of points to remember.

Mppt will only start charging once panel voltage goes more than 5V over battery voltage. So if your 48V battery is at 56V, panels need to be over 61V for charging to start. Add up VOC for panels in series to check.

Mppt will keep charging while panel voltage is more than 1V over battery voltage.

Panel voltage drops with heat, more critically rises as temps drop. So you need to allow for coldest winter temps.

Use the above to play with basic configurations, like panels in series, and as @Alexandra said, set up the calculator and see what it says. You also need to decide on Bluetooth MPPT or not and connector type.

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Alexandra avatar image Alexandra ♦ commented ·
With the higher voltage (VOC) panels you will be looking at the higher voltage charge controllers like the 250/100 or 250/85 will do (3s 2p config) if you are trying to keep your string voltages higher.

Or you can use 2series 3 parallel config (higher amp input) and use the 150V mppt range. I am less of a fan of doing hat if you have high temperatures in your area the mppts will struggle to start as @kevgermany mentioned 5v above battery.

You have 6x 550W that is 3300W. At 48 volts that is 68.75 amps of charging at STC ratings of the panels. So any charger with higher amps than that will be fine.

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weslleyphinverter avatar image weslleyphinverter Alexandra ♦ commented ·
I got the MPPT 250/100 MC4

Do you know how much solar power I can use ? I was thinking to increase at 4400 watts solar panel. 8 x 550W.

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weslleyphinverter avatar image weslleyphinverter weslleyphinverter commented ·

Almost I use on grid this system, only when the grid is off that I will start to use the inverter mode.

My idea is export to the grid my energy while I dont need to use the inverter ( like 2 or 3 times per year for no more 4 hours each )

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