Hello there!
I had a AC200 sitting for about 6 months (charged to ~80% before disconnect) and now have extremely low output and a single cell with very low voltage:
I’ve charged three times to 100% and then discharged with a 200W load. State of Charge drops from 60% to 0% in an instant, the unit shuts off and cell 1 reports ~2.6V when you restart.
When initially turning the unit on it was barely able to display the menu for 2-3 seconds, then shut off again. After numerous tries the AC charger started charging. The lowest i’ve seen the cell was at 2.1V 
Is there a way to revive the cell?
There is an internal XT90 connector with ~54V that seems to connect “directly” to the Battery or BMS - is it viable to charge there with a dedicated charger set to let’s say 54.1V at around 1 Amps
Is there any kind of balancer in those units? I wonder why the low voltage cell does not aligns its voltage over time with the rest of the cells. The unit has been sitting for an hour, other cells at 3.29V, cell 1 still at 2.62V
Thanks!! 
Hi @DReffects, since the AC200 is over-discharged, if AC charging is unable to wake it up, using DC(solar or car) charging should be feasible.
Please confirm that the solar panel’s VOC should be between 35- 150V.
If you need further assistance, please feel free to contact our customer service team. I hope it does help.
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Thanks for the switft feeback. AC charging is possible at the moment and the unit charges to 100%.
Cell voltage of the affected cell remains a bit lower though and after a short amount of usage the unit powers off due to undervoltage warning for this cell.
What can I do?
Hi @DReffects
Did you leave the unit for a while after charge it to 100%?
The balancing of the cells might take a while. I would recommend to charge it to 100%, leave it and check if the inbalance getting better over time.
greetings
Erik
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Hi @DReffects, We’re concerned that this AC200 may have been over-discharged.
Besides AC charging, have you tried DC charging? Did it have any effect?
Also, please refer to @Selfmadestrom’s suggestion to recalibrate—did that help?
If the issue still persists, I’m afraid you’ll need to contact our customer service team and send the unit to a repair center to attempt a deep charge recovery.
If you’re unsure how to reach the service team, please send me a message with your order information, and I can assist you in arranging it.
Hello Erik @Selfmadestrom ,
I left the unit with 80% SOC over the weekend to found it dead this morning. After restarting the unit with the AC Charger plugged in, it reported 0% SOC and started charging.
Going into the cell voltage screen I saw cell 1 at 0.81V, rising fast.
@BLUETTI_CARE
I retired the unit last summer with 80% SOC - other cells were at 3.10-3.15V when I restarted the unit.
How would I go exactly about the recalibration? Right now it seems the unit shuts off as soon as cell 1 reaches ~ 2.6V while all the others are still at 3.25-.3.29V
It it save to charge the unit via DC with the AC Adapter connected to the DC Port?
Hi @DReffects, It appears AC charging is not working. Please try DC charging instead—this includes car charging or solar charging. Please use a DC charging cable (not the AC adapter) to connect to a compatible power source.
Please confirm that the solar panel’s VOC should be between 35- 150V.
Please follow the steps below to recalibrate it:
- Please discharge all the power until the SOC is 0%, turn off the machine, and leave it for 3 hours till it cools down.
- Please charge it again, please do not load any device when charging it, and do not interrupt it while charging.
You can click this link for reference.
Please let us know if it does help.
Hello @BLUETTI_CARE , thanks for the step by step guide.
I’ve followed the instructions but the unit behaves differently, compared to the video.
The unit shuts off AC Output after ~ 15 minutes of 1000W draw but stays on. SOC is being reported at 0% while cell voltages look like this:
As you can see all cells beside call 1 seem to have plenty of charge left (at least going by their voltage ~70%) while cell 1 made the BMS to shut off the output due to low cell voltage.
I tried charging with DC input by Solar (60V VOC) and the unit seemingly charges back to 100% (like with the AC charger) but cell voltage of cell 1 does not reach more then 3.2V while the other cells reach 3.39V.
Then the situation is the same like before: a short discharge brings Cell no 1 down to ~2.6V and the unit shuts cuts power.
Hi @DReffects, Charging separately seems to have worked, and you can now charge it to 100%. We recommend using a lower-power load for discharging—does this help?
As for the low voltage of cell 1’s issue, it cannot be fixed remotely. If it is affecting usage, you will need to contact customer service to arrange for a warranty.
