I cannot be the only one experiencing a particular force charge problem, so I just wanted to put this out there
I'm context, FOX admit there is an issue, and are looking at a solution. What surprises me is that I am convinced other would be trying to do exactly the same as me, hence this post.
In generic terms I have solar and battery, the size does not matter. In winter months, I am reverting back to the Octopus Cosy Tariff.
For the system to work properly, I need to force charge 3 times a day, (cheap rate periods) particularly in the afternoon so my battery is at 100%, to glide through the peak rate period early evening.
The problem is this, if the Force Charge is on, and the battery reaches 100%, my Solar shuts down completely, and the power from the Solar goes absolutely nowhere.
What should happen is that with the Force Charge on, and should the battery reach.100%, any excess Solar power should go to export.
Fox admit this is an issue and are currently trying to find a fix. Surely I cannot be the only one who is trying to do this?
Hi RugbyKev, I also have this issue since a firmware upgrade. (KH8 inverter: Manager 1.51 Master 1.5 Slave 1.02)
Before the upgrade it would force charge battery and use solar. Now it shows as no Solar generated at all.
It would be good to know the latest firmware that didn't have this issue.
Before the upgrade it would force charge battery and use solar. Now it shows as no Solar generated at all.
It would be good to know the latest firmware that didn't have this issue.
Thanks for this. Really interesting as I have had the system less than a year, and it was my belief that originally the solar did use to work during the Force Charge period.chubber wrote: ↑Wed Oct 22, 2025 11:01 am Hi RugbyKev, I also have this issue since a firmware upgrade. (KH8 inverter: Manager 1.51 Master 1.5 Slave 1.02)
Before the upgrade it would force charge battery and use solar. Now it shows as no Solar generated at all.
It would be good to know the latest firmware that didn't have this issue.
Reading up further on this, apparently some systems are designed this way to protect the system from any sort of overload, which I get, but I think the software programming should be robust enough to prevent any overloads.
I am in regular contact with Fox on this and they say R&D are on this, so watch this space.
Yeah it's not an overload thing. PV generation would have been relatively small at the time and it wasn't charging at full inverter capacity.
But the fact it then doesn't use Solar for the duration of the slot(?) that's not right.
But the fact it then doesn't use Solar for the duration of the slot(?) that's not right.
Is the reason for your force charge the same as mine?
I.e the use of Cosy Tarrif. The afternoon slot is the most important as need to get the battery up to 100%, by 16:00 to glide through the evening to 22:00.
Great to do this via solar, but if there isn't enough solar, the force charge is to ensure the battery is at 100%.
Should it be a cold day we need the heat pump to kick in which consumes about 8kw/HR, so would soon drain our 10kw, battery as a result.
Should I have the force charge on currently with the current set up, I would just lose all solar power produced in the afternoon, which is neither right or acceptable.
I'm on Intelligent go so occasionally make use of assigned cheap slots or free electricity sessions.
Your usage scenario seems perfectly reasonable. It definitely seems to be an issue that's been introduced recently.
Your usage scenario seems perfectly reasonable. It definitely seems to be an issue that's been introduced recently.