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databeredning asked

SmartSolar MPPT common DC minus between battery and load?

I am installing a Victron system in a friends old boat.

I got a SmartSolar MPTT 75/15 for the solar panel. However, I can not separate the DC minus of the battery system to the load outup. The previous owners have used a dc minus where ever then found it and the only used a DC+ to the switch board for lights etc. Cables look ok, gauge is ok for the fuses used. So my only issue is that I dont know if the SmartSolar MPPT is ok with connecting the the battery and load DC minus together.

PV array has its owns cables, + and -, they are not connected to anything else than the PV terminals.
1718092244948.png


If not I will have to use an BP-65 that is controlled by the SmartSolar.
But when I view this schematic, it tells me that the load- minus is the same as the Bat-, as the BP-65 is using the Bat- as reference for the load output voltage.
1718092275520.png

MPPT SmartSolar
1718092244948.png (152.6 KiB)
1718092275520.png (70.6 KiB)
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2 Answers
klim8skeptic avatar image
klim8skeptic answered ·

@Databeredning Unfortunately the mppt load output is switched on the negative.

Connecting the mppt load op neg to the batt neg will disable the mppt load output switching.

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databeredning avatar image
databeredning answered ·

Ok, I was afraid that was the case.

We will install a BP-65 to do load switching.

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