System has stopped charging 100% overnight
I have had a Fox ESS solar system for about 9 months now inc through the UK winter.
I have it configured to charge the batteries from the grid overnight (02:00-05:00) at the cheap rate of electricity.
I have noticed that since late February the batteries are only charging to about 60% vs the 100% they achieved before that.
The weather has not been cold.
Why might this be happening? With the batteries failing to charge to 100% we struggle to make them last the day.
I have changed nothing on my end in terms of configuration.
I have ensured I have the latest software.
Re: System has stopped charging 100% overnight
Fox have been pushing firmware updates out so it’s likely you have been updated and the old charge method needs an update.

Can you post an image of what settings you use for the charge, i.e. is it a force charge in a schedule or a charge period ?
Re: System has stopped charging 100% overnight
Hi
I have added a screen shot of the settings used
Attachments:
IMG_0163.jpeg
Re: System has stopped charging 100% overnight
What size battery do you have?
Those 3hrs would gain a max of 6kWh.
Re: System has stopped charging 100% overnight
Ok thanks,

how big is your battery ?, at a 2,000W charge power it would only get a max of 6kW in the 3 hours allocated - previous firmware versions ignored the 2kW and charged at the maximum rate which might be the reason you are only getting to 60%
Re: System has stopped charging 100% overnight
Sorry @MB you beat me to it ;)
Re: System has stopped charging 100% overnight
Dave Foster wrote: Sun Mar 08, 2026 5:08 pm Sorry @MB you beat me to it ;)
Always good when you post at same time. :D
Re: System has stopped charging 100% overnight
I have 10kwh battery capacity.
If the old firmware ignored the max charge rate - that would explain why it got to 100% before, and I certainly see a higher rate in early February.
Thanks all - I will increase the max charge rate tonight and see how it goes.
Re: System has stopped charging 100% overnight
Perfect, I am sure you will be ok now.

Fox have been pushing firmwares out, and adjusting back end database settings recently.
Re: System has stopped charging 100% overnight
I really appreciate your help.
I had tried Fox support to no avail 😔
Maybe deliberate to push customers here.
Re: System has stopped charging 100% overnight
Update
Having increased the max charge rate setting, all is working well again now and reaching 100% charge overnight again.
Thanks again all!
Re: System has stopped charging 100% overnight
Glad it worked out for you.
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