HI all !
I find strange behavior of my installation. The installation does a short power export several times a day, with the battery only 15-20% charged. See attached pic. Can anyone explain this behavior ? Thanks in advance.
Feed-in power shows with battery charged only 15-20%
-
Dave Foster
- Posts: 822
- Joined: Thu Oct 13, 2022 7:21 pm
That looks like data lag caused by the 5 minute data sampling the cloud uses.
When the inverter load changes when a larger load turns on or off, the inverter has to balance the demand from the batteries - if the data sample is taken when it is balancing you sometimes get data lag and what appears to be either a grid import or export.
These peaks last for only a small moment of time whilst the inverter adjusts it's power but because the data sample is every 5 minutes it appears more significant than it really is, it's just a normal part of the inverters operation - if you connect via modbus RS485 you can sample at 3 seconds and you can see then that the peak is only a transient thing only showing for one sample.
(Induction hobs are particularly good at causing this as they switch the load on and off rapidly)
When the inverter load changes when a larger load turns on or off, the inverter has to balance the demand from the batteries - if the data sample is taken when it is balancing you sometimes get data lag and what appears to be either a grid import or export.
These peaks last for only a small moment of time whilst the inverter adjusts it's power but because the data sample is every 5 minutes it appears more significant than it really is, it's just a normal part of the inverters operation - if you connect via modbus RS485 you can sample at 3 seconds and you can see then that the peak is only a transient thing only showing for one sample.
(Induction hobs are particularly good at causing this as they switch the load on and off rapidly)
Thank you very much for the explanation. I also took the measurements directly from the inverter. See the attached picture.
Of course the amount is very small, but it is there.
Of course the amount is very small, but it is there.
- Attachments
-
FoxESS Hybrid-WR H3-8.0-E
FoxESS Batterie ECM 2900 Master/Slave with BMS
LiFePo4, 2,9 kWh x 3
Astronergy PV Modul CHSM54M-HC BL 400Wp x 20
FoxESS Batterie ECM 2900 Master/Slave with BMS
LiFePo4, 2,9 kWh x 3
Astronergy PV Modul CHSM54M-HC BL 400Wp x 20
-
Dave Foster
- Posts: 822
- Joined: Thu Oct 13, 2022 7:21 pm
Yes it’s a grid tied inverter and normal, there will always be a small import & export, once the sun starts shining in warmer months all of these numbers will become noise in the overall statistics.