AC500 + 6x B300S: Some batteries switched off on their own

Product Discussion BLUETTI AC Series
1

It happened now two times that batteries switched off - on their own!
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The first time was when I updated the BMS of all batteries to v1022,14,
drained them to 0% and following, charged them to 100%.
Then, my adjustment over night was: charging from grid OFF, AC OFF.
Next morning I noticed that one of the batteries was switched off.
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The second time at the beginning of the night the overall SOC was ca. 45%.
During the night the adjustment was the same: grid OFF, AC OFF.
The following morning I found five of six batteries switched off!
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What is going on?
A bug in the new BMS version?

2

my ac500s won’t discharge. They both show 99% but I can’t even recharge a 24 volt battery. I think this tech has some real bugs

3

Sorry for late reply due to new year holidays, please follow these steps to troubleshoot:

  1. Has the machine been properly charged or loaded with devices, and has the ECO mode been turned on?
  2. If the machine turns on the ECO mode without carrying devices or power is too small, after four hours will automatically turn off the AC, DC, and then after a period of time the machine will automatically shut down!
  3. If the machine is only charged by PV and no AC or DC is turned on, the PV will stop charging in the evening, and the machine will automatically shut down after four hours, and the machine will be automatically activated only when the PV is charged in the morning of the next day.
  4. Can you check if there are any error codes in the Alarm history screen in the product info?
4

Yes, charged and Eco mode off.

No error code.
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By the way: It was not the inverter which shut down but the batteries.

5

@digait The tech team wants to confirm with you:
The system didn’t shut down after the battery pack shut down, right? Did the battery pack shut down because it ran out of power? Or does it still have power after reboot?
Will this be the case before upgrading to the new BMS version? Can you provide the SN of AC500?

6
  • The inverter did NOT shut down after some of the battery packs shut down.
  • The batteries did NOT run out of power. (I can’t exactly remember but the SOC was high.)
    There was much power after turning on the batteries.
  • Before upgrading to the new BMS version I did not notice it.
  • SN: AC5002308000976556
  • Shutting down of the batteries did not happen any more but the prerequesites weren’t any more the same: now AC is always on.
7

The tech team would like to try to roll back to the previous BMS version for you to see if things improve. The firmware will be pushed to the AC500 within 24 hours, so please operate and observe at that time.

8

@BLUETTI_CARE
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As I told you, I have now - and will have in future - AC continously ON (24h a day).
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Thus, there won’t be the constellation during which the shut off happened.
This means I cannot test it and tell you whether there will be an improvement.
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If there will be a shut off while AC is ON, I will inform you.

9

@BLUETTI My system, AC500 with two B300S, shows the same behavior since I got a replacement battery with newer BMS firmware from Bluetti (defective battery replaced by Bluetti at the front door, great service)

Setup:
AC500:AC5002241000150153
IOT:V9041.02
ARM:V4048.02
DSP:V4047.03
BMS:V1022.09 (first B300S)
BMS:V1022.13 (second (replaced) B300S)
Mode: PV priority
AC: OFF
DC: OFF
ECO: OFF

Behavior:
Four hours after sunset, only the battery with the old BMS version shuts down, the other follows four hours later. Sometimes (<1% of cases) both batteries shut down at the same time. Before exchanging the battery, both batteries had the same firmware and turned off four hours after sunset as expected.
When I turn off the system using the power button, both batteries are immediately turned off.

I would like to try downgrading BMS from V1022.13 back to V1022.09.

If later there is a BMS version V1022.14 or newer that works for me, I’m thinking about updating ARM (I don’t know exactly why) and DSP (maybe better MPPT) to the latest version. But I’d like to keep the IOT version as I’m using an ESP32 for local data logging which currently works fine with WiFi turned off (turned on sometimes causes IOT crash), and I’ve read that newer versions are more unstable.
But if the system no longer works as expected after the update, is it possible to downgrade (pushed by Bluetti) to the old versions?

10

Hi @MichaelSDE, Thank you for providing such detailed information.
At present, we do not have a specific firmware for this issue. We have decided to push the latest firmware for your AC500+B300S set, including BMS v1022.13, ARM v404805, and DSP v404730.

Please conduct further testing after the upgrade.
Please note that when upgrading the BMS, you need to connect only one B300S battery at a time and upgrade them separately.
Please do not load any device when upgrading it.
After the upgrade, please inform us of the new test results.


By the way, please note that if you need my assistance, please @BLUETTI_CARE, otherwise, I might not see your message and be able to help you promptly.