6x B300S - Extremely unbalanced

I will do that when I finish calibrating my last new battery in a few hours. And yes, I’m only connecting a single battery at a time for the calibration process. What is the latest BMS version for the B300S?

For @BLUETTI_CARE, Success. After completing the calibration for the 2nd new B300S, I reconnected all four batteries to the AC500 and there was no change to the Home SOC display. It read 39% or roughly half what it was supposed to (the two older B300S were at 79&80% and the two new ones were both at 100%). Then I updated the BMS on the two older units from 1022.08 to 1022.09 and as soon as I reconnected everything, the Home SOC immediately changed to 90%, which is what it should have been. I rechecked all four batteries using the app and it reports that all the BMSs are up to date, even though the older two are at 1022.09 while the two new ones are at 1022.13. Is this correct and there’s no reason to try to find any updates for the .09 units to get them to .13?

While doing all this, I noticed that the app also reports that my AC500 has available updates. Specifically, ARM from 4044.04 to 4044.07, DSP from 4045.04 to 4045.30, and IoT from 9041.02 to 9041.10. The latter 9041 one says it adds the Bluetooth encryption feature, but I have no idea what the ARM and DSP add or fix. Should I go ahead and upate all of those (IoT, ARM & DSP)? Thanks for your help.

Hi @TMan, Regarding this issue, we believe that pushing the new BMS firmware to the two older batteries is a good solution. Please provide us with the SN code of your AC500 so that we can push the new BMS firmware.


As for the ARM v4044.07, it resolves the issue of being unable to configure settings via the touchscreen.
The DSP v4050.30 fixes the problem where solar charging power is limited under high-power AC loads.
The new IOT firmware optimizes Wi-Fi connectivity and app data statistics.
If you are not experiencing these issues, there is no need to upgrade these firmware versions.

Hallo BLUETTI_CARE,
I’m also need the DSP v.4050.30.

AC5002241000324376
IoT2236001010612

Thanks Joachim

Hi @BLUETTI_CARE. I actually have two AC500 units, one with the four batteries (the two new ones plus two older ones), and the other with two of the older batteries. Since I may need to move batteries from one to the other in the future, please push the new BMS firmware to both of my AC500s so I can easily upgrade all four of my older batteries.

(1) AC500 - 2239000831419
(2) AC500 - 2252000462587

I appreciate your help.

Hi @Akel, Can you tell us the current DSP version of your AC500?
Then we will apply for pushing the new DSP for you.


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.

Hi @TMan, Thank you for getting back to us so quickly.
We have now requested to push the latest BMS to your two AC500 units. The push will be completed within 24 hours. You can upgrade tomorrow or whenever it is convenient for you.


Please ensure that only one B300S battery is connected during each upgrade. Please do not load any device when upgrading it.
After that, please try to do a complete cycle of discharge and charge to correct the SOC. The problem will be resolved.

Please follow the steps below to recalibrate it:

  1. Please discharge all the power (charge AC & DC appliances with the power station) until the SOC is 0%, turn off the machine, and leave it for 3 hours till it cools down.
  2. Please charge it again, please do not load any device when charging it, and do not interrupt it while in charge.

Thanks @BLUETTI_CARE. Will do. With 4 batteries to update & recal it’ll take me several days to complete, but I’ll post how it went after finishing the process.

"Hallo BLUETTI_CARE,
I’m also need the DSP v.4050.30.

AC5002241000324376
IoT2236001010612

Thanks Joachim"

My actual DSP-Version is 4047.30.

Hi @TMan, Yes, We have pushed the latest BMS v1022.14 to your two AC500 units. Please connect only one battery at a time for the upgrade.
However, during the recalibration process, it is not necessary to calibrate each battery individually.
We look forward to your feedback on the new firmware.