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learaviator avatar image
learaviator asked

Smart shunt issue

Hello everyone, my Smart shunt keeps saying the batteries at 100% by 8:30 in the morning which is not possible. The panels are barely producing at that time and I keep setting the smart shunt to 100% as soon as my charge controller goes to float. Seems like it is close to OK for a few days and then it starts indicating 100% way too early. My MPPT250/100 is still showing bulk charge and the smart shunt is saying 100%.

SmartShunt
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Alexandra avatar image Alexandra ♦ commented ·

@learaviator

Going to repeat the mantra here. More details please and current settings.

I guess would be your tail current and charged voltage values though.

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learaviator avatar image learaviator Alexandra ♦ commented ·

Sorry about that, I’m just new enough with Victron and lithium to not know what information you might need. I am attaching screenshots from the smart shunt and the MPPT control.

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learaviator avatar image learaviator learaviator commented ·

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Iii

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learaviator avatar image learaviator learaviator commented ·

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Ii

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1 Answer
pwfarnell avatar image
pwfarnell answered ·

Your charged voltage setting is much too low. Tje shunt synchronises to 100% when tje voltage is above the charged voltage AND the current is below the tail current. With solar this set of conditions occurs not long after the solar starts charging. The charged voltage MUST be set 0.2V to 0.4V below the absorption voltage set on your MPPT. Therefore, if you normally charge at 28.8V, set the shunt charged voltage to say 28.4V. Therefore, for the shunt to synchronise to 100% it has to be charging at close to full voltage and below tail current which means the batteries will be full.

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