question

pangani avatar image
pangani asked

Wind & Solar Feature

Having initiated the new Wind & Solar Prioritisation feature I’m finding that batteries are charging from shore power when solar isn’t available despite batteries being at or within 1% of 100% SOC. I was expecting the batteries to supply the DC load overnight and then top back up from solar during the day.

Firmware updated on both Cerbo GX and Multiplus 12/1600/70-16. Multiplus advanced setting changed to ‘Prioritise Other Energy Sources’ and Sustain voltage set to 13.3v for AGM batteries (as per instruction to set it to 0.2v below 12v battery Float of 13.5v).

VRM shows the Multiplus in Sustain mode and prioritising solar for the batteries (and DC loads) during the day but shore power taking over from the solar and keeping the batteries topped-up at 100% (and DC loads) during the night.

DVCC and ESS are both disabled.

Marine system (12v DC) is Cerbo GX, Multiplus, AGM batteries, 500w solar panels, Victron MPPTs x2, Victron SmartShunt 500A

What have I set-up incorrectly?

screenshot-2023-09-19-at-162450jpeg.png

solar wind priority
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1 Answer
derrick thomas avatar image
derrick thomas answered ·

The inverter/charger is going to supply what is necessary to maintain the sustain voltage you have set of 13.3, regardless of SOC. If you want to limit battery charging during periods of no sun, you will need to lower the sustain voltage. It is doing what it is designed to do.

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pangani avatar image pangani commented ·
That makes sense, thanks. The set-up guide does state that the W&S Prioritisation is purely voltage driven but it is confusing as it then goes on to recommend setting Sustain voltage to battery float charge -0.2v which conflicts with the objective to optimise W&S.
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derrick thomas avatar image derrick thomas pangani commented ·
If you want to maximize the wind and solar priority I would suggest setting the sustain voltage to something like .1 to .2 volts above the batteries resting voltage. That should reduce the shore power charging during periods of no sun.
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