AC500 Split Phase

I have two AC500’s each with one battery. They are hooked up split phase with a fusion box and are charged with four 320W solar panels, 2 panels for each unit. The outlet side of the fusion box is not connected to anything as I am waiting on the delivery of a Generlink transfer switch.
If the units are left on but with no load (both AC out and DC out set in the OFF position and nothing plugged in), the batteries lose about 20 percent of their charge overnight, about 8 hours.
is it normal for the batteries to lose charge even with no load???
if the solar input is shut down (i.e. it is dark) and both units are turned off, the batteries remain charged, but when turned back on there is a split phase alarm which takes a few minutes to clear.
during initial set up, both batteries were cycled from zero SOC to 100 SOC three times

Hi @oldtoad

welcome to the bluetti community forum! Thanks for your question.

Every unit have a certain selfconsumption, even when its just on without any load. There are many components inside a powerstation that requires a certain amount of energy, when turned on.

When the unit is off, everthing goes into some kind of sleep mode. This consumes far less energy than active standby.

About the Split Phase alarm, maybe @BLUETTI_CARE or @BLUETTI can help you with this matter. I dont have this mode in my country.

greetings
Erik

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Hi @oldtoad, Based on the current information, a 20% power consumption overnight is indeed unusually high and does not seem normal.
Please inform us of the ambient temperature where the AC500 is located—is it within a suitable room temperature range? Additionally, provide us with the SN code of your AC500 and the current BMS version, and we will attempt to push a firmware update to resolve the issue.
As for the split phase alarm, this may be due to the split phase mode being set while one of the AC500 is not powered on, causing a recognition failure and triggering the error. Please check the specific error code so that we can further analyze the issue.
We extend our gratitude to @Selfmadestrom for the solution and assistance.

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things might be OK.
after dark last night (no solar power input), I tuned the AC out OFF. after a couple of hours, the units must have shut themselves down. being asleep, I did not witness this.
in the morning, the master unit had dropped 2 percent and the slave 4 percent. there was a split phase alarm, but that cleared once both units were powered up.
perhaps that 20 percent drop that occurred earlier was an anomaly.
both units are set up inside where the temperature varies from 68 to 85 degrees F.
the master is: AC5002438000094784. BMS: v1022.13
the slave is: AC5002252000425080. BMS: v1022.09
the app says my versions are up to date.

Hi @oldtoad, Thank you for sharing; we are glad to hear that the issue no longer occurs.
However, since the two AC500 units operate in a split phase, it is best for them to have the same BMS version. This will allow for better SOC balance and improved BMS performance.


We have applied to upgrade your BMS; our IT department will push the latest version of firmware to your 2 AC500 separately in 24 hours. Please upgrade it tomorrow.
Please disconnect these 2 AC500’s connections, and only connect 1 B300S, which needs to be upgraded, and do not load any appliance when upgrading it.


After that, please try to do a complete cycle of discharge and charge to correct the SOC.

Completely normal. I have a total of 8 batteries and AC500 and AC300. They all self consume power. I run my units 24/7. My AC300 units power my pool and are at 100% when the son goes down around. My pool stops running about an hour before sun set. By morning time my units are between 70-80% since they self consume.

as of March 11;
upgraded BMS version on both batteries to v1022.14
discharged both units to zero
charged both units to 99 percent
set AC output to ON. set DC output to OFF.
disconnected all loads
at 10 PM both units were at 99 percent
at 6 AM the next morning, both units read 78 percent.
is it normal to lose 21 percent with no load?

Hi @oldtoad, We recommend that you charge up to 100% during recalibration rather than 99%. Conducting a capacity test when the battery is not fully charged is not scientifically sound.


When the AC500 has its AC output turned on, the self-consumption is 27.4W, while the standby power consumption of the B300S is 2W.
Over 8 hours, the total self-consumption for 2 AC500 units and 2 B300S units is:
2 pcs (AC500) x 27.4W x 8 H + 2 pcs (B300S) x 2W x 8 H = 470.4Wh
I hope it does help.