EP11 (not) heating issue

[nrb501]

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

[nrb501]

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.

[doubl0dave]

Hi there, have you found out any more information about this issue please? The heated battery function for me only seems to work when solar is coming into the system. I have never seen it run on my own battery power at all (even when battery is fully charged) and am concerned this will be a problem in dark and cold mornings and evenings. Thanks.

EP11-H

[insanegl0ss]

I’ve got the same issue. The battery goes into standby when the heater trigger point occurs, regardless of SoC (it was 91% when it occurred today).

I’m calling my installer to update my firmware as I’m on 1.006 on BMS.

[nrb501]

This is how I believe the heater "should" behave:

1. If SoC >40% then when cell low temp is below threshold heater should operate and battery stays online whether heat from grid is set or not.
2. If SoC <40% then when cell low temp is below threshold heater should only operate if heat from grid is set, then battery will go offline whist heating.
3. If heat from grid is not set and SoC <40% then when cell low temp is below threshold heater will not operate and battery stays online.

But I have seen in #1 with heat from grid disabled, the battery go offline with no heating occurring. In this scenario enabling heat from grid enables the heater and the battery stays online. I've not checked if firmware 1.009 corrects this.