Hi everyone,
I’m hoping to get some guidance on an issue I observed today with my off-grid setup.
System components:
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Victron Multiplus II - 3000 - 48V (off-grid setup)
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Victron MPPT charge controller
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Dyness B4850 batteries (3 units in parallel, each with 2,4kwh)
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Cerbo GX
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DVCC enabled
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PV array sized to fully charge the batteries during the day
What happened:
This morning my system showed 74% SoC, which seemed realistic.
I turned on my Mitsubishi split heat pump (heating mode), which at the start drew around 1300 W AC. It then went down to about 600W. Under this load, the battery voltage dropped to just below 48 V.
Within about 45 minutes, the VRM showed the battery SoC falling from 74% to only 5%, and then the batteries shut down.
However, according to my Victron data, I had consumed only 0.8 kWh during this time — so the drop from 74% to 5% doesn’t make physical sense.
Has anyone seen similar behavior with Dyness batteries under moderate loads?
Any help or troubleshooting suggestions would be greatly appreciated!
Thanks in advance!
