Slow overnight charging

Something has changed over the past 3 months, I have two 9KWh batteries controlled by the Inverter. The maximum rate of charge is now down to 1KW/hr, meaning the off-peak period gives me only 5KWh of energy…. Why are my batteries charging so slowly?

They are roughly 10-15c inside my garage.

They used to charge at 3KW/hr only 6 months ago.

RBisset
What inverter please and what firmware version are you using.
What tariff are you on.
Have you "reset inverted to default" using the portal

Thanks for responding, I appreciate it.

My GIV-AC3.0 inverter is running D0.205-A0.205 software

The two 9.5KWh batteries are on firmware 3017,

RBisset it sounds very much like it is temperature related charging throttling. If your garage is 10-15 degrees then the battery cells are likely to be lower than this, and that’s what’s causing them to charge so slowly.

1kWh is quite slow though, they normally throttle back to around 2.4

Yes my 9.5KWh batteries at between 10-20c should charge at 3.16KW/hr at above 10c and 2.38KW/hr at below 10c

Something is clearly wrong...

Do you think my firmware is up to date?

GIV-AC3.0 inverter is running D0.205-A0.205 software

The two 9.5KWh batteries are on firmware 3017,

RBisset Two batteries on the one inverter should not be throttling due to temperature. Each one shares the 3KW from the inverter so effectively 1.5KW each well below even the 10oC throttling point.

Reset to defaults first then ask GE to explain.

Windy Miller OK, I have clicked the restoe to defaults button and saved. I will see what happens tonight.
I am assuming contacting GE is practically impossible?

RBisset If you did the reset you should check and adjust the settings you require for charge/discharge so they are set up again. Then monitor it does what you want. Even a short sanity test might be worthwhile to check throughput.

I dont know much about 2 battery setups but I thought they normally tried to keep the charge levels close to each other? Hopefully others on here can advise

RBisset
I have an AC3.0 with 2x5.2KWh batteries so am interested to see what you need to do to sort this. My battery charging level is still at 3KW. Batteries also in the garage and currently at 10oC.

Inverter Firmware Version D0.204-A0.204
Battery Firmware Version 3015

Windy Miller My suspicion is that the firmware update D0.205-A0.205 for the inverter started my issues. I see you are on the older inverter firmware - I suggest you keep it that way until I get to the bottom of this one.
In the meantime my electric bills are through the roof...

geoffreycoan I can't quite remember what/when he said it but Hoggy said the table is wrong.

I also have a vague recollection of him saying that the BMS registers had a high/low value for cell temperature which might be used to determine when to throttle charge. Easy enough to see those values with GivTCP or the Inverter app.

@TheDragon (GivEnergy) I believe this was an issue you explored on another thread? My AC3.0 inverter will only charge at 1kW/hr - is there a simple fix for this?

RBisset
what are the 11 notifications saying/telling you?

SteveCook
They are old notifications, the firmware update seems to be the likely candidate for this restricted charging malarkey...

RBisset
Sorted
Tested and charging at 3kw (2800W DC) now

If you adjusting discharge (Assume for exporting) Use The inverter power %% registers.
They only apply to export schedules.
What you had set would also limit ECO mode discharge power

RBisset electric bills are through the roof...

You had a DC discharge power setting of 1300W, limiting the inverter output
Ive set this back to 3000W
If you are limiting power for Exporting, use the registers designed for such
Inverter Discharge Power %. Range 1-100%

TheDragon has upgraded the firmware of my two 9.5kW batteries from 3017 to 3019 - problem solved.