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Multiplus II and Victron MPPT with Lead Carbon Battery Issue

Good Morning Community,

We have a customer with an existing Victron Multiplus and MPPT installation (done by solar installer) who is not getting charging current into the batteries in mid afternoon after the Lead Carbon batteries hit around 80-90%. This is a completely Off-Grid installation with back-up generator. 14kW of Solar available. 40kWh of Lead Carbon batteries. Here is the graph.

Diagnostic Suggestions welcome...

Multiplus-IIESS
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2 Answers
safiery avatar image

Thank you Boekel . The second graph in the image has battery voltage and current from the Solar controller. Do you mean these values as measure by the 712 on the load side?

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Boekel avatar image

Judging by the graphs, the batteries doesn't seem to accept more current.
It would help if you post the battery voltage / current graph, and not (only) the solar graph.

It looks like there was a peak in power usage around 9:30 that brought the charger back in bulk, before that the current dropped fast at absorption voltage.

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