question

kkesp avatar image
kkesp asked

Low watts from solar panels.

I have 3 LG 420 watt panels connected in parallel through a combiner box connected to an Smartsolar MPPT 150/100. The first few day after I turned my system on the Solar watt gauge on the app showed around 890 to 940 watts it was a partly cloudy day so I expected this. However today it's clear and sunny but I only showing about 80 watts solar on the app. Does the charge controller limit output from the panels once the batteries get to 100% SOC? I assumed the gauge on the app would show how many watts the panels were putting out regardless of battery SOC.


MPPT ControllersSolar Panel
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1 Answer
Kevin Windrem avatar image
Kevin Windrem answered ·

You nailed the situation. Once the batteries are charged, there is no where for the solar energy to go. The gauge on the app DOES show what the panels are putting out, however the charge controller is throttling back from what the panels could produce to prevent overcharging the battery. If you put load on the system the PV output will increase because there is now somewhere for the energy to be consumed.

The charge controller senses full battery when the battery voltage reaches the absorption value and charge current tapers off to something close to 0.

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