FoxESS Community - Owners & Installers Forum

July 2023 I had the fox engineer out to update the firmware in my 2 x lv5200
batteries (connected to a solis 3.6kw inverter). The issue was that the
batteries were not fully charging and causing the system to draw from the
grid. The update work got exerting back in sync and working. Recently over
the past 2weeks similar issues have reappeared. The batteries will only
charge between 90% and 93% on off peak overnight charging and during the
day the batteries stop charging at 80%. Have the batteries went out of
balance?

Just got a rather unhelpful short message from Fox saying “contact soils please”. I have previously spoken to Solis and they have been great…issue seems to be with the two batteries

I'm not that familiar with Solis inverters, but the problems sound similar to what you would see if the batteries were cold, or the Inverter's charge voltage limit was set too low.

You tend to see higher cell voltages when charging from solar than grid which could explain why it is only allowing 80% on solar, and ~90% on grid charge.

I'm afraid I don't know enough about the inverter to advise, so it might be worth posting this question on a Solis group or raise a support request on Solis for advice - you would be looking for setting for the upper charge voltage - it might be called 'equalising' or something similar but it should be set to 57.6V.