AC300 weird handling of SoC low vs. (time of use / grid usage / grid charge switch)

Hi @BLUETTI_CARE, this is a case I deem interesting to report because it looks strange to me.

Context : Customized UPS + SoC low/high = 8%/35% + time of use = “off-peak” between 2:00AM and 7:00AM (“peak” the rest of the time) + “Charge from grid” = OFF.

S/N = AC300230900018163
IoT = v9041.06
ARM = v4037.05
DSP = v4053.20
BMS, battery pack 1 = v1021.06
BMS, battery pack 2 = v1021.07

Report:

  1. During the night, AC load consumption tripped SoC to fall below “SoC low=8%” and therefore (I suppose) this switched my AC300 grid usage ON to avoid complete battery depletion (this is good)

  2. At 9.00AM this morning, checking the AC300 status, I saw that even though being now in “peak time” + SoC being 12% = significantly above “SoC low”, the AC300 was still using grid to power the load (only, I suppose… since charge switch is OFF)

  3. Now the super strange fact : switching “charge from grid” from OFF to ON made the grid consumption to suddenly stop !!!

  4. and switching “charge from grid” back OFF did not change anything - which at that time looked normal.

My interpretation of that behavior :

  • when discharge crosses the “SoC low” level, grid usage is turned ON, regardless other settings, to both charge the battery and power the load, ok.
  • but then when SoC returns above “SoC low”, an no matter being now in peak time, seems the above situation continues : AC300 “forgets” to switch grid usage OFF, whereas I would have expected grid usage to stop or be enabled back again only if SoC low is crossed again…
  • And acting manually on the “charge from grid” switch, even from OFF to ON, makes AC300 to suddenly “remember” to check the situation and act = stop using grid because SoC>“low” + time=“peak” …

My take is : you have a bug in the truth table or the process watching the machine status & making decisions from the events [SoC low, time of use, grid charge switch] …

Can you check?

@LLaurent I have reported this issue to R&D and will let you know if there is any update ASAP. The simple suggestion at the moment is to restore the factory settings and then reset the UPS.

@LLaurent The R&D department believes this is normal. In the custom mode, grid-off and time-on are the same as in the PV priority mode. The preset value of the PV priority mode has a hysteresis to avoid frequent switching back and forth. Therefore, if the machine continues to charge for a while when the SOC is 12%, the grid will stop bypassing the load.