question

Andy Todd avatar image

Battery Monitoring

I have a battery monitor on my Mastervolt Combi system control panel with the shunt on the -ve side of the battery bank (420Ah 12V). I have 2 banks of PV into 2 Smartsolar MPPT 100/20's.

Three hours after coming off shore power at 100% charge the Mastervolt says 30% power left, 313ah used and discharging at about 7.5A with 13.56V. Victronconnect on the MPPT's says Solar = 42V, 1 to 3A, 50W network. Battery 13.6V, 3.3A and Float.

What's going on? Am I assured that the Mastervolt is telling lies? Maybe I have the -ve side of the MPPT on the wrong side of the shunt. What side should it be on?

Thanks

charging battery
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2 Answers
wkirby avatar image
wkirby answered ·

MPPT negative should be on the shunt terminal that is not connected to the battery. If the MPPT is directly connected to the battery negative, then the energy will not be counted.

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Andy Todd avatar image
Andy Todd answered ·

Thanks, but why is the Mastervolt monitor showing the info it does. Is the MPPT charge confusing it or is it tellng me the truth... and my batteries are in trouble?

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