FoxESS Community - Owners & Installers Forum

I have a H8 inverter with 47kwh battery installed about 3 weeks ago and for the life of me I cannot get my battery to reach 100pc. It tops out at 97pc about 10am and it hadn't budged since.
I have an image from the FoxCloud app and figures from the modbus dongle export.

Even when I schedule a force charge, its still uploading to the grid. What is going on here??

-- Modbus Sensors
Ambient Temp (Inverter) 48.8 °C
Battery Charge (Inverter) 0.00 kW
Battery Charge Today (Inverter) 5.00 kWh
Battery Charge Total (Inverter) 123.60 kWh
Battery Discharge (Inverter) 0.41 kW
Battery Discharge Today (Inverter) 7.40 kWh
Battery Discharge Total (Inverter) 257.40 kWh
Battery SoC (Inverter) 97%
Battery SoH (Inverter) 100%
Battery Temp (Inverter) 40.4 °C
BMS Cell mV High (Inverter) 3,375 mV
BMS Cell mV Low (Inverter) 3,359 mV
BMS Cell Temp High (Inverter) 30.8 °C
BMS Cell Temp Low (Inverter) 26.9 °C
BMS Charge Rate (Inverter) 25.00 A
BMS Discharge Rate (Inverter) 50.00 A
BMS kWh Remaining (Inverter) 46.08 kWh
Connection Status (Inverter) Connected
CT2 Meter (Inverter) -0.00 kW
Feed-in (Inverter) 0.00 kW
Feed-in Today (Inverter) 23.70 kWh
Feed-in Total (Inverter) 71.50 kWh
Grid Consumption (Inverter) 0.04 kW
Grid Consumption Today (Inverter) 0.30 kWh
Grid Consumption Total (Inverter) 4.00 kWh
Grid CT (Inverter) -0.04 kW
Input Energy Today (Inverter) 0.20 kWh
Input Energy Total (Inverter) 2.10 kWh
Inverter Battery Current (Inverter) 0.80 A
Inverter Battery Power (Inverter) 0.41 kW
Inverter Battery Voltage (Inverter) 486 V
Inverter Current (Inverter) 1.30 A
Inverter Fault Code (Inverter) None
Inverter Power (Inverter) 0.26 kW
Inverter State (Inverter) On Grid
Inverter Temp (Inverter) 44.1 °C
Load Energy Today (Inverter) 4.60 kWh
Load Energy Total (Inverter) 192.00 kWh
Load Power (Inverter) 0.29 kW
Max Charge Current (Inverter) 5.00 A
Max Discharge Current (Inverter) 50.00 A
Max SoC (Inverter) 100%
Min SoC (Inverter) 10%
Min SoC (On Grid) (Inverter) 10%
PV Power (Inverter) 0.00 kW
PV1 Current (Inverter) 0.00 A
PV1 Power (Inverter) 0.00 kW
PV1 Power Total (Inverter) 0.000 kWh
PV1 Voltage (Inverter) 2 V
PV2 Current (Inverter) 0.00 A
PV2 Power (Inverter) 0.00 kW
PV2 Power Total (Inverter) 0.000 kWh
PV2 Voltage (Inverter) 2 V
PV3 Current (Inverter) 0.80 A
PV3 Power (Inverter) 0.00 kW
PV3 Power Total (Inverter) 14.031 kWh
PV3 Voltage (Inverter) 274 V
PV4 Current (Inverter) 0.60 A
PV4 Power (Inverter) 0.00 kW
PV4 Power Total (Inverter) 14.917 kWh
PV4 Voltage (Inverter) 219 V
Solar Generation Today (Inverter) 34.90 kWh
Solar Generation Total (Inverter) 331.00 kWh
Version: Manager (Inverter) 1.58
Version: Master (Inverter) 1.6
Version: Slave (Inverter) 1.02
Yield Today (Inverter) 28.50 kWh
Yield Total (Inverter) 260.60 kWh

If you can show your power graph for the day in question (click on PV production will do) and you should see a green SoC charge line. Does the SoC line reach 100% or not ever?

Typically the battery SoC will flip between roughly 96% to 100% in cycles, as it doesn't like to be stuck on 100% for too long in Self-use mode.

I've never seen it reach 100pc. I got it about 3 weeks ago where it would reach 99pc but for the past 10 days or so it's only reached 97pc. I assuming that's because of drift or the BMS has calculated its voltages better.

I have attached the graph, I hope it's the correct one you wanted

I would recommend then that you try and bottom out your system to 10% and hold for a few hours, and then allow it to go to 100% and hold for a few hours also.

Running the same Inverter FW here, and battery seems fairly accurate with the BMS reported %

I did want you suggested, dumped the battery down to 10pc over night and its only just now recharged itself. Its still only hitting 97pc.
Any other ideas?

It would typically take a few cycles to allow the BMS to learn the end points.

Next is, have you powered everything off, and restarted things? Making sure to power the battery off last, and first on the start-up sequence.

If one of your battery packs came with more or less SoC % out of the box, then this could be causing an issue. They usually arrive with around 50% SoC give or take, if one pack was higher/lower then that could drag them all down.

Firmware for the Inverter is fine, but can you find out what is happening with the battery firmwares?

Temperature will affect the battery packs also, mine charges to 100% overnight... discharges down to around 55% (give or take) each morning... and it will "gain" power as the day warms up (no PV charge/grid charge) Are your batteries exposed to the Sun for example.

I have shut the whole system down previously.
Shutoff the solar.
Turned off the AC mains.
Shut the butter down, turn off the breaker switches.

I did all this when the battery was as full it allows, reports, which is 97pc.


Your comment about the battery coming with more then around 50pc, obviously I can no longer check that

BMS Version is 2.011

Temperature Wise, i'm in Queensland, Australia so it doesn't really get cold. The system is in the garage.
Lowest Temp is 25.75
Higest Temp is 33.5

Yeah I know you can no longer check the individual SoC of each pack, just me saying that you could take a fair few cycles to get things back (if at all)

Being in a garage is good, though mine still loves to increase the SoC each day

Try and get a few more cycles performed with it, and see how it goes. I dare say Fox will ask the same of you before they go further with investigations.

I would agree with @MB about the cell balancing as 97% is usually the point it stalls and performs it’s top balancing which might take a number of charge cycles if one of the batteries is a lower soc than others, But it might also be worth checking the inverter settings as on the latest KH firmware they have added another MaxSoC setting which is only available to installers and in the inverter settings screen.

I imagine at some point it may be exposed through the app but for now go into your inverter settings at it’s front panel, enter the password (0,0,0,0), then Battery, and on latest versions of firmware there will be a ‘MaxSoC’ and a ‘MaxSoC from grid’ setting - make sure both are set to 100% if they exist.