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sungunner asked

MPPT 100/30 Smart Network choosing wrong shunt for voltage and current monitoring!

I just added solar to my RV using 4-100 watt panels connected in parallel to a 100/30 MPPT to charge my East Penn 2-6V House batteries (23 Ah) with it's own Smart Shunt with a temperature monitor. I also have a 2nd Smart Shunt connected to my Starter battery all running on a Venus Large network running on a PI4. I'm using default (2) setting on the MPPT. All is good. BUT when I joint the MPPT controller to this network things go seriously wrong.

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The MPPT automagically selects the Starter battery for the voltage and current sense. When this this happens, the MPPT injects over 16V into the House Batteries!

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When I drop the MPPT from the smart network, all is good but I lose the temperature monitor on the House Batteries. I then went into the MPPT settings and changed some of the settings to the East Penn specifications for 6V FLA GC batteries. Absorption 14.1V, Float 13.5V, and Equalization to 14.2V (even though it's disabled). Still didn't work.

So then I disconnected the power to the Starter battery Smart shunt and power cycled the MPPT. It started working as expected. I then reconnected the power to the Starter Battery shunt and the MPPT switched again to using the Starter Battery voltage and current at the monitor and then the MPPT began overcharging again!

I don't see any way possible in the MPPT settings to select the monitoring source from the VE Smart network so for now I deleted the MPPT from the smart network. Am I doing something wrong? I'm looking for some help to fix this issue. I really don't want to cook my new House batteries!

MPPT SmartSolarSmartShuntVE.Smart Network
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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Just remove the starter battery from the smart network.

If the MPPT is changing the house battery then the information from the starter battery are not relevant for the smart network.

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