18kpv pulling from grid for a few hours, unexpectedly

[millsan1]

So today, from about 11 AM to 6 PM, my 18 was pulling from the grid, even though I had plenty of battery, and it was pulling from battery as well, but a flat 3-600 watts, the whole time.

Loads varies between 1 and 4 kw, but when the load spiked, more grid was used.

I decided to try and sé what was up, when out of nowhere, went back to normal, using all battery.

Weird.

Today was a very rainy day, so little pv production and there seems to be a little correlation between PV production and battery use.

Any ideas?

 

[marionw]

How are you monitoring the batteries and the Inverter.
Are you operating in "closed" or "open" loop? In other words is the BMS of the "Master" battery connected to the BMS port on the inverter.

If you are in "closed loop" it's possible the batteries are reporting something different with respect to SOC that what your monitoring software is indicating.

If you are in "open loop" the inverter can only determine battery SOC by voltage which is wildly inaccurate.

And of course, your inverter settings also play an import role...

 

[millsan1]

How are you monitoring the batteries and the Inverter.
Are you operating in "closed" or "open" loop? In other words is the BMS of the "Master" battery connected to the BMS port on the inverter.

If you are in "closed loop" it's possible the batteries are reporting something different with respect to SOC that what your monitoring software is indicating.

If you are in "open loop" the inverter can only determine battery SOC by voltage which is wildly inaccurate.

And of course, your inverter settings also play an import role...

Closed loop. Lifepower4 with hub. Hub showing same thing as 18. Nothing changed as far as settings go. Been running with current config for a while. First time this happened

 

[marionw]

You need to monitor/look at each battery in your stack with the BMS_Tools software to ensure the batteries are all balanced with each other.
Over time batteries will get out of balance with each other and individual battery SOC will get out of wack with respect to that batteries cell voltages and battery overall voltage.

Periodically you will need to manually take change of the battery charging process to get each battery to the point where the BMS starts balancing the cells. Once the BMS starts this it will reset SOC (and what it is reporting to the hub).

The Hub may display good data but in closed loop the hub also controls/overrides a number of Inverter settings.

Look at each battery with the BMS_Tools software to determine if one or more batteries are significantly different.