FoxESS Community - Owners & Installers Forum

Weird issue this morning when the battery cell temp dropped below the set trigger point for heating (3°C, outside temp was -2°C). Battery dropped to standby but heater did not come on although the app implied it had - no increase in cell temp over about an hour and the battery case was still cold. Yesterday when I tested the heating function by raising the trigger point to 6°C with cell temp at 5°C heating worked as expected.
After disabling the heating function and then re-enabling it after 5 minutes the heating seems to be working again - WTF?
Inverter f/w 1.48, Battery 1.007

Ahh - just realised that the battery will only use energy from the grid if "Warmup Slot in low price" is enabled otherwise either PV energy is used or battery charge needs to be above a certain level (55% ?) to self heat.
When this was all happening there was virtually no PV generation and battery charge was 54%
Also it seems that when the battery is being warmed up it will not be charged or discharged by the inverter.

Documentation of these systems seems to be very thin so resulting in the potential for a lot of trial and error before arriving at a efficient configuration - it seems also a lot of installers are not as knowledgable as they could be.