Massive Celldrift in 1 Battery, BMS don`t work

Product Discussion BLUETTI AC Series
1

Hello,

I have an AC500 with 2x B300 + 1x B300s.
One of my B300 units has an extreme cell drift, which has been present from the beginning. I thought the cells would eventually balance out, but I’ve tried everything: charged to 100%, completely discharged, fast charging at 10A with 230V, slow charging at 1A with 230V, charged without mains power on the solar input - nothing works!
It seems to me that the BMS has not been working from the beginning. Here is a picture at 100% charge:
What can be done about this?
Best regards,
Jo

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IMG_81094032×3024 1.73 MB

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Hallo,

ich habe eine AC500 mit 2xB300+1xB300s.
Bei einer meiner B300 habe ich einen extremen Celldrift, dies war von Anfang an so. Ich dachte dass die Zellen sich irgendwann angleichen, habe alles probiert, aufgeladen auf 100%, komplett geleert, schnell aufgeladen mit 10A bei 230V, langsam mit 1A bei 230V, geladen ohne Netzspannung an dem Solareingang - es bringt alles nichts!
Für mich macht es den Anschein dass das BMS von Anfang an nicht gearbeitet hat, hier mal ein Bild bei 100% Ladung:
Was kann man da machen?
Grüße
Jo

2

Can’t help with the cell drift, but how do you get the screen with the individual cell voltages to appear on your unit? I have an AC500 with two B300s batteries and haven’t found a way to show that level of detail on mine.

3

Here you can find it :-)

1 Like
4

@derJo If charge and discharge cycles do not resolve the issue, please contact after-sales support to replace the battery pack.

1 Like
5

I came here to say the exact same thing. @derJo Run a couple complete 100% - 0% - 100% cycles on the unit and see what happens. I would bet that things will settle up for you, but keep us posted. :slight_smile:

6

I assume you have discharged and recharged your “faulty” B300 alone, unconnected to the other expansion batteries and AC500 ?

7

Thank you Marcus. I don’t want to divert this discussion, but I do appreciate the information on how to show the battery cell voltages. That was very helpful!

8

Hello,
it’s all ok!
That’s what the forum is for :-)
Marcus