@BLUETTI_CARE I have updated BMS via Bluetooth. AC200L BMS is now v1043.14 and both B210 BMS is now v1036.06. I will recalibrate and update you with the result in a couple of days. Thank you.
Hi @Iusachev, Thank you for reaching out to us.
It’s completely normal to have different firmware versions due to variations in production batches and device models—there’s no need to worry at all.
We’d like to check if you’ve encountered any issues during actual use. If everything is working smoothly, there’s no need to upgrade the firmware.
Hi @dmc, Thank you for the update—we’re glad to hear you’ve received the new firmware and completed the upgrade!
Yes, recalibration is required after updating the BMS.
We look forward to your feedback on how it works.
I have recalibrated once and it is still unbalanced.
In my earlier post it was the AC200L (pack1) that was permitted to discharge to 0% while both B210s were still at 34% and 39%. After firmware update it is now B210 with s/n ending 88120 that is discharging faster.
It was somewhat balanced when 88120 was removed, ie just AC200L and B210 s/n 25349. Why does B210 s/n 88120 discharge faster than other two packs ? I think 30% difference between packs is high. Is there no smart BMS coordinating charging/discharging status among the three packs ? It does not seem optimised for balance.
Unfortunately Bluetti App graphs under Energy Statistics do not log SOC on per pack basis, only overall system SOC.
I will let system discharge again until first pack hits 0%. I will then power off, cool, disconnect load and recharge by grid to 100% and observe SOCs again with load connected.
My stats:
Numbers on left are the last 5 digits of pack S/N.
62278 =AC200L Pack 1 48%
88120=B210 Pack 2 19%
25349=B210 Pack 3 50%
Power down and Remove 88120
Power up
25349 now seen as Pack 2 (1st downstrream)
62278 =AC200L Pack 1 47%
25349=B210 Pack 2 50%
Overall 48%
Turbo charge
62278 =AC200L Pack 1 64%
25349=B210 Pack 2 56%
Overall 60%
Standard charge
62278 =AC200L Pack 1 79%
25349=B210 Pack 2 62%
Overall 70%
Silent charge
62278 =AC200L Pack 1 79%
25349=B210 Pack 2 62%
Overall 70%
Eventually both packs charged to 100% and overall SOC 100%
Several hours pass…
62278 =AC200L Pack 1 47% discharging
25349=B210 Pack 2 56% discharging
Overall 51%
Power down
Reattach B210 88120
Power up
AC grid disconnected
AC output off
62278 =AC200L Pack 1 37% charging
25349=B210 Pack 2 42% charging
88120=B210 Pack 3 33% discharging
Overall 37%
It appears 88120 is donating power to other two packs even though 88120 is lowest SOC.
AC output now on. AC load (fridge) attached drawing 55w periodically when compressor kicks in. B210 88120 discharges 33% to 22%. Difference between 88120 and 25349 is 22%.
62278 =AC200L Pack 1 36% standby
25349=B210 Pack 2 44% standby
88120=B210 Pack 3 22% standby
Overall 34%
Hi @dmc, Thank you for sharing the test results!
We believe that in most cases, the power difference between these three batteries falls within an acceptable range.
Additionally, we recommend that before paralleling the units, you ensure all three batteries have the same charge level first—this manual process helps balance the power distribution.
Did this method yield any positive results?
During full discharge the packs become better balanced the closer overall system reaches 0% SOC. Once pack 3 dropped to 4% SOC the other two packs discharged more to equalise.
62278 =AC200L Pack 1 16%
25349=B210 Pack 2 14%
88120=B210 Pack 3 4%
Overall 11%
62278 =AC200L Pack 1 8%
25349=B210 Pack 2 8%
88120=B210 Pack 3 2%
Overall 6%
62278 =AC200L Pack 1 2%
25349=B210 Pack 2 1%
88120=B210 Pack 3 1%
Overall 1%
62278 =AC200L Pack 1 0%
25349=B210 Pack 2 1%
88120=B210 Pack 3 1%
Then system reached 0% and inverter switched itself off. Wifi stayed on.
It is improved after the firmware update and the extra recalibration.
Thank you
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Hi @dmc, Thank you for the update!
We’re glad to hear the new firmware is working—seems like the BMS is doing its job to balance the power levels of each individual battery cell.
@BLUETTI_CARE I seem to still have balance issues after several charge and discharge cycles. Please see photo
Please advise.
Hi @Ellimatt37, Thank you for the update.
We’ve noted that the power difference between the two batteries is not significant—it falls within an acceptable range. This will not have a substantial impact on practical use.