Have a look at the snapshot I took. It shows that even though the battery was nowhere near empty (91%), it's still drawing power from the grid at random times.
One second it's drawing power from the battery and the next it draws from the grid and then goes back to the battery.
Why does it do this?
JH
Because the invertor cannot provide the power required instantly.
If you switch your kettle on, the power will come from the grid initially...very briefly, until the inverter has time to ramp up and provide the power.
But this happens randomly (generally in the evening) with no new equipment being turned on.
Everything is stable and then you see a watt come in from the grid here and there.
it doesn't require anything new turning on. Something that is already on can vary it's power requirement. Also the inverter monitors the grid feed using a clamp, and tries to match it to 0, this clamp itself has inaccuracies and interference so the reading may change even if the grid feed doesn't. Anyway, 1 watt for a handful of seconds is essentially 0, and certainly is from a cost point of view.
Jetheat if your inverter is supplying say 300w from battery and all of a sudden demand is 400w, the inverter will take a short time to add that additional 100w. This could be from something needing more power (light, TV, charging your phone, etc).
Also, the inverter needs to communicate with the grid to get voltage and frequency and does this with a small amount of energy.
1w is miniscule in the short term (would take 1000 hours to use 1 unit of energy), and check what your overall daily import is.
Ok cool, that makes sense.
All boils down to inaccuracies and catch up time.
Thanks.
For 10 minutes, the grid started to supply power while the battery only supplied partial power, even though it was almost fully charged.
How comes it did that for a full 10 minutes or so?
I don't think catch-up would take that long!
JH
Jetheat Looks to me you exceeded the inverter load of 5kW so the rest comes from grid