AC300 Customized UPS mode setting fails to cut off power output at SOC low setting

Although it should, according to the manual. I set the setting at 95% Battery SOC High and at 5% Battery SOC Low. The former one works well - the unit stops charging once it reaches 95% SOC. It fails to turn off AC output on its own though - I had to switch it off manually at 2% SOC tonight. What am I doing wrong? Thanks

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It’s probably a bug. Other people have the same problem.


@Oleksiy When the high value of SOC is reached, the output will not be cut off. But the machine will turn off the utility input and the remaining power can only be filled by PV charging.

@BLUETTI Yes, and this is very good - I’m interested in AC output to be on once the SOC high value is reached, this part works well. I was referring to the operation of SOC low setting instead - it’s not enforced properly. It’s crucial to protect the AC300 from draining the battery and down to the level when the unit is unable to load and charge it anymore. I don’t have any way to charge my B300 directly yet.

@TheQuickFox Thank you, it’s good to know I’m not alone. It’s not good that the feature won’t work though. Hope there are plans to address this in the next firmware release.

I have a AC300+B300 and have the same problem with the low SOC. It is not stable at the low end. So I set my low SOC to 19% and It works fine. Sometimes it drops below 19% but never below 15%. I think the hardware has a problem keeping it at 19% but the workaround is doing great on my AC300.


@hey Thank you, this may be a great workaround, will try it today.

To update, I managed to check the low SOC AC turn off setting today. Set it to 11%, it failed to disconnect AC output power until 1% SOC when I had to do this myself. The feature does not work, apparently. @BLUETTI , please assist with this, if possible.

@Oleksiy I’m very sorry for the late reply due to the Lunar New Year holiday.
A low SOC value will not cut off the AC output.
But at 11% depends on the load and input power, if the load power is greater than the input power, the battery power level will still continue to drop

@BLUETTI Ok, thank you. I thought the meaning of SOC Low setting was to cut off AC power at this level of SOC, as the instruction manual and screen instructions suggest. If this is not the case, such a setting would be very useful - please consider introducing it in the firmware update. It should not be more difficult than stopping charging at SOC High, which works well now.

@hey This won’t work for me for some reason. The AC output won’t shut off even at 1% SOC under SOC Low setting at 20%.

You are correct, the AC output does not turn off. I use my Acc300 as a UPS system and one requirement is that the AC300 stays on until the battery hits 0%. The SOC stops charging the battery when the AC300 hit the low SOC so that is why I set my low SOC at 19% and it is working fine. Never have the AC300 die, yet.