AC200MAX suddenly losing its charge when not in use

Product Discussion BLUETTI AC Series
1

Hello,

I am having an issue with an AC200MAX suddenly losing its charge when not in use (it went from approximately 50% charge to 0% overnight, this has happened twice now in the last day).

Is there a possible fix for this issue ?

The product serial number is SN : 2246000564216

I am located in South Africa.

2

Hi @Ruimtemuis !

First off all, you should try to calibrate the SoC by following this video:

If this doesnt help, some more information would be useful like what exactly mean “not in use”?

Is the unit fully turned off or still on but without a active load?

Thanks
Erik

1 Like
3

Hi @Ruimtemuis, We would like to know whether you turn off the AC/DC output or shut down the AC200MAX completely when not using it at night. A complete shutdown can minimize unnecessary power loss.


We appreciate Selfmadestrom’s detailed explanation. Yes, recalibration can restore the AC200MAX to optimal battery performance.


Additionally, could you let us know your current BMS version? Please ensure it has been upgraded to the latest version.
Is this effective? If you still need assistance, feel free to contact us anytime.

4

Thank you for the reply Erik.

I have done the recalibration procedure as indicated, but haven’t yet had the chance to check if the problem is fixed.

When I say not in use, it just means the AC200MAX (attached to a B300 battery expansion) had nothing pulling power from it overnight (when in use, it is connected to my house’s grid, but was disconnected), and also was not being recharged).

The battery’s percentage went from about 50% to about 20% (I don’t remember the exact figures), and when checking the details on the screen, it was only showing discharge on the AC200MAX side, not on the B300.

Kind regards,

Benjamin

5

Thank you for your reply.

Yes, I did a complete shutdown.

I have done the recalibration, but don’t yet know if the problem is fixed.

In the meantime, this is my current BMS version : 1017.02

I have attached some photos.

Please let me know if I can provide anything else that might help. Thank you.

Kind regards,

Benjamin

IMG_20250322_105520_739
IMG_20250322_105520_7394208×3120 1.25 MB

IMG_20250322_105513_676
IMG_20250322_105513_6764208×3120 1.15 MB

6

Hi @Ruimtemuis, We have rolled out the new firmware BMS v1017.02 in batch. Please log into the Bluetti app directly to upgrade.

Important notes during upgrade:

  1. No need to connect battery packs;
  2. Ensure all loads are disconnected;
  3. For optimal performance, we recommend performing recalibration after the upgrade.


Please let us know if this resolves the issue.