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geofffie asked

SmartSolar 100/30 with BMV712. Solar output Watts affected by current draw.

Since I added the BMV712 the Solar output as shown in the Connect app seems to be affected by the amount of current being draw from the battery. eg. If no power is being used, the Solar output drops to a low level, eg 7W, if a load is applied it rises eg to 60w. Consequently the history does not show an accurate record of panel output.

This is a SmartSolar 100/30 with BMV712 on a 12v system with 2 panels in parallel with an output voltage of 38v.

It may have been displaying this behaviour before the BMV712 was added but I don't think so. Can I have wired up something wrong? I looks right to me, has anyone got any suggestions?

At this time of year the charger is spending most of it's time in Float as the battery is fully charged.

Any help appeciated.






MPPT SmartSolar
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2 Answers
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wkirby answered ·

I'm not sure if I understand the problem.
You seem surprised that the PV output increases to meet the demand of a load that is switched on.
If the PV power is low before the load is turned on then the battery is most likely full so there is nowhere for the PV power to go until a load is turned on.

I'm sorry if I misunderstand, perhaps you could provide more information,like the state of charge at the time, if the MPPT is in Float or Absorb or Bulk and the battery Voltage level at the time of the PV power increase.

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geofffie answered ·

The batteries are fully charged. I thought from the Connect manual that the display showed what was comming from the panels but I am now thinking that it only shows the power that is being converted. Is that right?

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·
It is showing the power coming from the panels but there is only power coming if power is needed.

If your batteries are fully charged the MPPT will stop charging and if you turn on some loads the MPPT will try to supply the loads from the panels.

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