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smt asked

% soc measurement without BMV

In installations where there is no BMV, with CC GX installed, you only see the value of the SOC in the Color Control that rescues this value from the inverter. We know that the inverter is far less accurate than the BMV. In the inverter we configure the battery monitor section to show the correct value. We also find it odd that when this value is set, the screen shows 100% battery, knowing that the batteríes are not 100%.

We would like to know for this kind of cases that we can do so that the client has a reliable % SOC measurement. Especially when there is no BMV installed.

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1 Answer
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abrahamsolar answered ·

Hi from the USA, @SMT. If >>all<< energy to & from the battery moves through the Victron inverter/charger...its SOC calculation would be much the same as if you had a shunt & BMV type amp hour monitor.

Many installations, however, have energy reaching the battery or departing the battery which cannot be known by the multi--specifically if solar arrays are DC coupled to the battery by way of an MPPT charge controller or PWM charge controller...because that energy does not travel through the multi on its way to the battery. OR: if there's a Phoenix battery charger or engine alternator driven recharge for the coach battery, etc. those also cannot be known by the multi. OR: if there are DC lights or DC appliances...that is energy departing from the battery without the multi having a clue.

I'm including a shunt & BMV even on some "all AC" projects (in which even the solar energy moves through the multi, AC coupled). The additional reason to include the shunt & BMV is if the client ever wants to measure the amp hours capacity of the battery bank to see how it's holding up, using the menu function called "Consumed Amp Hours". It's a handy yardstick to have in place.

Sunny Days!

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