question

unifiedcommsguy avatar image
unifiedcommsguy asked

Is my MPPT cactus?

I am wondering if my MPPT Solar Charge Controller either is faulty or has bad software?

Video Link: VictronConnect Screen Capture

It is constantly fluctuating between full and no power as per the attached video. My setup is as follows:


12v LiFePo4 Battery -> Victron BMV-712 -> 16mm2 [50cm] -> 300A BusBar 8mm studs

Victron SCC MPPT 150/35 - 16mm2 [50cm] - 300A BusBar 8mm studs - (note: 16mm2 is max for MPPT 150/35 SCC)

Victron Phoenix 12/500 Inverters x 2 - 10mm2 [50cm] - (note: 10mm2 is max for Phoenix 12/500 Inverter)

MPPT Controllersfault
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4 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

What battery do you have exactly?

Maybe the internal BMS cuts off the charging due to a high cell voltage.

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unifiedcommsguy avatar image unifiedcommsguy commented ·
I have built the battery, LiFePo4 with BMS. No issues on the BMS side and as I've mentioned cables and connectors are all up to spec.


The voltage on the battery is fine and I don't detect a low voltage on the terminals of the MPPT


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seb71 avatar image
seb71 answered ·

Some other 150/35 SmartSolar chargers seem to have this issue. Should have been fixed by 1.56 firmware, but it seems that not in all cases.

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unifiedcommsguy avatar image unifiedcommsguy commented ·
Yeah I was aware of previous issues in firmware. Running 1.59 now.
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jeffles avatar image
jeffles answered ·

I'm having this same problem with a 100/30 running on 1.59. Is there a fix for this?

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nickdb avatar image
nickdb answered ·

What revision is the MPPT (you can see this in vrm under the device info)?

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Related Resources

MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

Faults with Victron equipment are best discussed directly with your dealer - this can be formalised with this support request form.