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kwagner avatar image
kwagner asked

SmartShunt current shows 50% less than real current draw

Final Update: Bringing up the second of eight battery boxes all is working correctly. Went back to the first box and discovered an assembly error that got over looked several times. By qualified eyes.

Update: Second SmartShunt 500A, out of the box and firmware updated shows same readings???

SmartShunt is showing 2.5A load when the measured draw on Fluke 375 shows 5A, which is the calculated load of the circuit. The SmartShunt has been zeroed with all devices disconnected, with no improved result.

Making a clever portable12VDC battery box.

  • KickAss Products battery box
  • NEPO 110Ah AGM Battery
  • Victron Blue Smart IP67 Charger 120 VAC 25A
  • Victron SmartShunt 500A/50mV Version 4.09
  • Victron Temp. Sensor for BMV & SmartShunt
  • Rhino DCtoDC Converter 12VDC to 24VDC 60W
  • BlueSea DC Fuse Bus and Neg Bus 6 Cir. 5025
  • BlueSea 30A terminal Fuse

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SmartShunt
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1 Answer
Trevor Bird avatar image
Trevor Bird answered ·

If the fluke is actually in series with the shunt and the numbers are not the same, the shunt is faulty. I think that would be extremely rare but the evidence cannot be denied. I would ensure the meter really is in series with the shunt with no other connections but the meter lead.

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kwagner avatar image kwagner commented ·

Thank you Trevor for your response and solid advice. This being my first experience with the SmartShunt 500A and posting to the community, it nice isn to confirm being seen.

Lucky this is not a complex work site. It is just all in front of us on the bench. Regarding the current measurement the Fluke 375 offers inductive AC/DC current measurement. So, it is not in circuit and not limited to 10A like most DMMs. Current was measured on booth the 12V and 24V circuits and the measurements matched the load configuration (test resistors) and paper calculation. 12V 5A pre DCtoDC and 24V 2.5A 60W post DCtoDC. We are building a series of eight of these boxes and will trying one of the other seven SmartShuts 500A that are on our bench Monday. I will post any useful updates. Cheers Ken

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