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akbast avatar image
akbast asked

Dual MPPT connected to Cerbo GX via VE.Can results in almost zero output from second MPPT

My system consists of a Multiplus II, two MPPT 250/100, SmartShunt 500A and a Cerbo GX. The MPII is connected to Cerbo via VE.Bus. The SmartShunt is connected to Cerbo via VE.Direct. The two MPPT are daisy chained to the Cerbo via VE.Can with terminators at each end.

My problem is that when the two MPPT are connected to the Cerbo, only one of them produces normal output and the other one is near-zero output. As soon as I disconnect the VE.Can, both MPPT produce normally as confirmed via VictronConnect. Plug VE.Can back in and it goes back to near-zero. This happens whether VE.Smart networking is configured or removed.

I have tried every possible combination of wiring and configuration and the end result is always the same. Is this a bug in the software or am I missing some fundamental configuration problem? If I switch to using VE.Direct connections to the Cerbo will I still have the same problem?


MPPT Controllerscerbo gx
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klim8skeptic avatar image klim8skeptic ♦ commented ·
A few things to check.

Are both mppts running the same firmware?

You are using can terminators at both ends?

You have not plugged into the bms can by mistake?


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akbast avatar image akbast klim8skeptic ♦ commented ·
They are both running v3.07 which is the latest firmware.

Yes I have the CAN terminators at both ends and I have tried every combination of order between Cerbo-Mppt1-Mppt2, Cerbo-Mppt2-Mppt1, Mppt1-Cerbo-Mppt2, Mppt2-Cerbo-Mppt1.

I confirmed there is nothing plugged into either BMS-CAN port.

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1 Answer
Trevor Bird avatar image
Trevor Bird answered ·
hello @akbast ....I wonder is DVCC active? Could you please see on the Cerbo is DVCC active and if it is, could you switch it to off and check the result? DVCC cab reduce charge from a device under certain conditions so this would at least eliminate that feature.
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akbast avatar image akbast commented ·
Yes! Thank you! Not sure how it got turned on but this was the problem. Everything working as expected now.
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