For a month now I have a b230 expansion battery connected to my ac200max that is being charged by solar, but the battery management is not working as is mentioned in the manual.
According to my understanding, the ac200max should keep the SOC of both devices at a similar level. In my case the b230 is depleted first and then turns itself off. It happened two times now that the SOC of the ac200max is at 50% and the b230 switches off. This makes the expansion battery not very usable.
I have completely charged and discharged both units together a couple of times to ‘calibrate’ the SOCs, but this didn’t help. Could it be because of the BMS versions? (see pictures).
And is there any progress on a software update that makes sure the b230 is not turned off, or wakes up when charge is available?
Any help or suggestions would be much appreciated, thanks!
I have the same effect here, the B230 batteries are also always discharged first.
Bluetti has promised me a firmware update, I have received nothing so far.
Whether I then update is uncertain, have already made in December a very bad experience with updates, then the box no longer worked, and had to repair.
Hello! Thank you @BLUETTI, I am happy to let you know that yesterday I have upgraded the firmware successfully. It went smoothly and quickly without any issues. I then charged both devices to 100% and during the night I have put a load on them. At the moment the SOC of the ac200max is still on 100%, the b230 is at 23%, so it seems that the new BMS does not keep the devices at a similar level and the problem still exists. I will continue discharging to see if the b230 completely empties first.
If there are any other options or thoughts, please let me know.
I have a 200Max and the B300 series battery and mine discharge at approximately the same rate, almost never more than 1 or 2% difference.
You can try doing what they call recalibration. You discharge both the AC200Max and your external battery to 0 and then fully recharge them with the AC charger. That will sometimes bring them back into balance. You might need to do it more than once. If that doesn’t help you should get in touch with the company again.
@rkrippner@BLUETTI Thanks for your suggestion! I will try it a couple of times more. Does it matter how the set is charged, by connecting the AC charger to the ac200max or the b230? When I connect the charger to the ac200max, the b230 turns off again, because it is empty and not being charged.
I’ve been told you should use just the standard AC charger when doing re-balancing. I don’t think it matters if you charge them separately or not. I haven’t done this myself but several people in the Reddit forum said doing this one or two times helped when the charge levels in the batteries got way out of whack like that.
I just scrolled up through the other replies and noticed you tried a firmware update. That was going to be my next suggestion. Try doing the rebalancing a couple of times and see if that helps. If not get in touch with Bluetti again.