Hi, sorry I searched but could not find this issue discussed.
Issue: "Slow Charging Speeds" when house load is high.
Scenario:
- House has 3 phase each circuit 100A
- H3-10-Smart with EQ-4800-L9
- Free Electricity Window 11am - 2pm daily.
Issue:
Battery charges at 9.9kw fine when house load is below 10kw.
If house load is above 10kw, battery will not charge or very low speeds. CT Clamps detect Grid Load as 10kw (at 50A capacity).
I get this is likely a safety thing, but seems it should be able to be increased to 90A (still 10% below the limit of a single phase)
My installer did not know how to fix this issue, other than have high-loads by-pass the CT clamp, but then the battery cannot be used to offset their loads.
Hello,
Your installer needs to speak with Fox support if they're unsure how to set the settings.
I would tell you what to change but it depends on inverter model and firmware version.
I assume they've updated you to the latest firmware and checked the common settings areas?
Your installer needs to speak with Fox support if they're unsure how to set the settings.
I would tell you what to change but it depends on inverter model and firmware version.
I assume they've updated you to the latest firmware and checked the common settings areas?
Community Admin / FoxESS Elite Professional
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Fox ESS Tri Inverter Installation
2 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
Dual Tesla Household
Heatpump & Low Carbon Housebuild





Fox ESS Tri Inverter Installation
2 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
Dual Tesla Household
Heatpump & Low Carbon Housebuild
Thank-you for taking the time to reply. I have also raised a support call with Fox. This was the installers first FoxESS 3-phase...Will wrote: ↑Fri Oct 10, 2025 8:59 am Hello,
Your installer needs to speak with Fox support if they're unsure how to set the settings.
I would tell you what to change but it depends on inverter model and firmware version.
I assume they've updated you to the latest firmware and checked the common settings areas?

Inverter: H3-10.0-SMART
Firmware: 1.3 (noticed it was updated last week without asking, now supports SOC of 0%, although I have left it at 10%)
Two things I noticed after this post;
- Balance Load: Disabled
- ImportLimitCurrent: 031.9A (~7kw at 220v)
Wild Guess: Given I can charge at 10kw, ImportLimitCurrent must be per phase, so perhaps I am maxing out one of the Phases.
Should I ask the installer to enable "Balance Load" and if that doesn't fix it, perhaps increase the ImportLimitCurrent to something a little higher like 040.0A.
Or am I barking up the wrong tree?
Out of curiosity, does it give you the same figure for battery capacity as before, or is the battery capacity show as 10% lower than it used to?spammenotinoz wrote: ↑Fri Oct 10, 2025 11:43 am ...
Firmware: 1.3 (noticed it was updated last week without asking, now supports SOC of 0%, although I have left it at 10%)
...
(I'm wondering if they've moved to a hidden-reserve, which is how 100% DoD batteries normally work, in which case it's just the way it is reported).
If they're actually letting you set reserve to 0%, and there's no hidden reserve, not sure how comfortable I am about that.
Great question, where can I check that.
Battery Details -> Health -> Capacity = --
Battery Details -> Health -> Capacity = --
Last edited by spammenotinoz on Tue Oct 14, 2025 11:30 am, edited 1 time in total.
Update:
During Force Charge today, battery started discharging today to provide the delta. Reduced house load to 8kw and battery started charging at 3kw. Stopped house load and battery charged at 9.1kw.
No response from FoxEss Support.
Following Up with Installer, but no fix yet.
Anyone else experienced similar charging an EV or otherwise during FREE Hours?
During Force Charge today, battery started discharging today to provide the delta. Reduced house load to 8kw and battery started charging at 3kw. Stopped house load and battery charged at 9.1kw.
No response from FoxEss Support.
Following Up with Installer, but no fix yet.
Anyone else experienced similar charging an EV or otherwise during FREE Hours?