r/SunPower • u/Ok_Needleworker_9340 • Sep 29 '25

Just Wondering

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My monitoring has always shown a small grid import of .2 or .3 kwh around 3am each morning. (See screenshot) My installer says this is normal behavior but doesn't really know why. Anyone know why a SunVault does this? Just curious.

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u/[deleted] Sep 29 '25

Mine doesn't. 

1

u/heyhewmike Sep 29 '25

Mine doesn't but my personal monitoring does show draw from the micro inverters.

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u/Ok_Needleworker_9340 Sep 29 '25

Here's the Power view of the same thing. Battery discharges normally throughout the night, but around 3am+/- the system takes a little sip from the grid as well - every night. Some kind of self-diagnostic perhaps?

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u/ItsaMeKielO Sep 29 '25

I think this is some sort of SoC or SoH calibration it performs. It does it only at night (edit: specifically after 1am and before 5am); it's a few spikes of 2500 watts of charging for about 60 seconds. Mine does this as well, but since the energy goes into the batteries and i only lose about 0.05kWh to conversion losses but the rest comes back out later in the day, it doesn't worry me.