Shunt connection question

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Henrik Voldsgaard

May 1, 2021, 1:30:21 PMMay 1
to electrodacus
I am a bit confused by reading the manual about shunt connection.
First of all, I am making a system fr my boat. I have no inverter and no solar panels. My Lifepo4 are either loaded from shorpower or via DC-DC from AGM (alternator).

1. Do I need 2 shunts?
2. According to the attached drawing - where to connect load and charging to shunts?

Thank's for your help

Electrodacus shunt question.pdf

Dacian Todea

May 1, 2021, 2:03:15 PMMay 1
to electrodacus

Yes your drawing is correct just extend those red lines :)  The Load connects to terminal 2 and the chargers connect to 4
You can also have a single shunt the ADC1n/ADC1p and connect everything to point 2 but then all the info you have is battery current and battery SOC can be calculated just from this.
But having two shunts provides way more info and it is worth the few extra $ for the PV shunt.

As an example say you get 35A from the chargers and say you have a 20A load then with a single shunt all that the SBMS0 will see is the +15A charge battery current and nothing else.
With two shunts the PV shunt will see the 35A from the chargers then it will see the 15A going in to battery and can calculate the Load current as 35A - 15A = 20A 

So with two shunts SBMS0 can show you charger current the battery current and calculated Load current while with a single shunt you only see battery current. 
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