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scaarup avatar image
scaarup asked

Monitoring mid of battery bank

Hi all.

I recently installed the smart shunt and I can see it can monitor the mid of a battery bank. Can you tell me where to monitor exactly?

Also should I connect the negative from the MPPT as "a" or "b"?

Thanks

monitoring
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The negative of the MPPT must be connected to"b".

With 3 batteries there is no midpoint...

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Mark avatar image Mark ♦♦ commented ·

It's not possible to monitor midpoint voltage in this setup because all batteries are wired in parallel (2, 3 or 4 makes no difference unless wired in series). :-)

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Kevin Windrem avatar image
Kevin Windrem answered ·

A couple of other observations:

1) for most accurate voltage readings on the Smart Shunt you should connect the positive lead directly to the battery. Depending on the length of cable between the positive battery terminal and the fuse there could be some voltage drop.

2) You don't show a fues in the MPPT positive connection to the battery. If that wire were to short to ground sufficient current could flow to cause a fire or at least melted wires.

The SYSTEM negative is the load side of the shunt ("b" in your diagram). All loads (and frame/earth ground) should be connected there. Nothing on the battery side of the shunt except for the battery. If you connect loads (or the MPPT) to the battery side of the shunt, that current won't be measured by the Smart Shunt so SOC and other calculations will be incorrect.

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scaarup avatar image
scaarup answered ·

Thank you very much for your answers - makes very good sense.

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