question

khachatur avatar image
khachatur asked

Battery or load priority in off-grid setup

Hi dear community,

I am designing a DC coupled off-grid system with PV+Smart Solar MPPT charger, Li-ion battery, Multiplus II and Cerbo GX.

Could you please tell me if by default VIctron has a battery charging priority in off-grid setups or load supply priority? If so, what is the SOC setting below which the priority is given to charging the batteries?

For example, what will happen if my battery is at 40% SOC and the PV generation is enough to cover the load? Will the system use the PV power to charge the battery or supply the loads?

Thank you in advance.

battery chargingoffgrid
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1 Answer
Alexandra avatar image
Alexandra answered ·

@Khachatur

With off grid, loads are priortized then battery charging.

You can set ac out 2 to switch off larger loads (and only switch on above a certain soc) to prioritze critical loads and battery charging.

So in short.... You can program it and set it up how you need it.

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khachatur avatar image khachatur commented ·
Thank you @Alexandra
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edclarke avatar image edclarke khachatur commented ·
@Alexandra, I'm looking at a similar situation using AC Out 2 as you described, but while connected to grid power. I would like to charge batteries while simultaneously powering an 120V AC heater on ACOut2. I have the Multiplus input limited to 18 Amps, and the heater load is about 15 Amps. Can you tell me how power would be prioritized in this situation? My hope is the Multi will power the loads first, then the charger. I'm using ACOut2 to prevent battery discharge in case grid power drops offline.
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Alexandra avatar image Alexandra ♦ edclarke commented ·
@edclarke

It will be the same. Just set the input current limit limit to the 18A or slightly above your loads, then it will run the loads and trickle what is left into the battery.

By default AC2 only switches on when there us grid.

Also by default virtual switch is on (where it only connects conditionally l. So you may also need to disable or change that as well.

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edclarke avatar image edclarke Alexandra ♦ commented ·
Excellent! Thank you.
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