Hello,
I have an ac300 with 4 b300s attached to it. Ever since the last firmware update, one of the b300s will not charge past 60ish% via solar. I have done a full drain without any luck. Currently I have that battery plugged to the ac300 by itself, and it stopped at 62%.
Please advise.
ac300
dsp 4031.30
arm 4032.11
hmi 6029.11
B300 - v1021.11
Can you test only the problematic B300 with your AC300 connected to utility power? All other batteries not connected? Will it charge past 60% now. If you discharge just that one battery and then recharge it, both via your AC300, will it charge to 100%?
Hi @rando_specs, Could you share your AC300’s SN number? We want to push the new BMS v1021.13 to help resolve the issue.
Thank you, @TheQuickFox, for your helpful suggestion. Please connect the B300 directly to the AC300 and charge it using AC power. Alternatively, you can disconnect it and charge the B300 separately using PV input. Note that the B300’s solar input voltage range is 12-60V, so please ensure your solar panel specifications meet this requirement.
Thank you @TheQuickFox ! I gave it a shot and it stopped charging at 96% this time. Was going to do a full drain and charge the next time, but looks like they’re going to push a new firmware out. 
Hi @rando_specs, Now I have applied to upgrade your firmware.
Our IT department will push the latest version of firmware to your unit in 1 workday.
Please upgrade the firmware tomorrow. Please do not load any device when upgrading it.
We suggest you recalibrate it after upgrading.
Please let us know if it does help.
Thank you @BLUETTI_CARE . Did the firmware update this morning and had been charging via solar. The SOC was at ~42% when it suddenly jumped to 100%. Is this normal?
Hi @rando_specs, Thank you for getting back to us so quickly.
It seems abnormal, please recalibrate the AC300+B300 set, which does help to resolve this problem.
Please follow the steps below to recalibrate it:
You can click this link for reference.
Please let us know if it does help.
If not, please contact us for further service.
@BLUETTI_CARE thank you! so I did the discharge and charged it back up to 100%, connected the other 3 batteries back together, now the ‘suspect battery’ will not discharge. it’s constantly at 100% whereas the other batteries have been discharging. they’re currently at 62%, 52%, 57%
It’s probably not it, but if you’re not tired of testing yet:
Can you connect the problematic B300 battery to your AC300 to a known good port and with a known good cable. Just to make sure it is not a problem with one of your cables or one of the battery connection ports of your AC300. Just to make sure you do not send in a heavy B300 for repair while the problem turns out to be with the connection to your AC300.
Hi @rando_specs, Please test if the cable might be causing the issue.
We’d like to confirm whether the problematic B300 can discharge properly when disconnected and tested independently.
Thank you, @TheQuickFox, for your helpful steps—they’re very useful.
If the standalone test shows the B300 still has issues, don’t hesitate to get in touch with customer service for a repair.
Hi @rando_specs, We would like to know the BMS versions of all 4 of your B300 batteries.
Do any of them have a version starting with 1014? If so, you may need to replace it with a unit of a different version.
Apologies for the slow response, I’ve been on vacation.
Thank you for the suggestion @TheQuickFox and @BLUETTI_CARE ! Unfortunately the cable seems to be fine. The other 3 batteries seem to need to be discharged a good amount before the ‘suspect battery’ starts to discharge. Then when the ‘suspect battery’ gets to 100% charged via solar (which is relatively quick since it gets discharged at such a late time) the other 3 batteries stop charging. Current battery range, 55%, 24%, 98% (suspect battery), and 40%.
I’m going to try a drain and recharge via grid with all 4 batteries connected to see if that helps anything. Well, i guess when the 24% battery gets fully drained LOL.
@BLUETTI_CARE nope, none are 1014.
pack 1 - 1021.11
pack 2 - 1021.11
pack 3 - 1021.13 (suspect battery and the one that got the pushed firmware update
pack 4 - 1021.11
@BLUETTI_CARE also looks like the other 3 battery packs have an update available but I’m not sure if that was just from the firmware push for the ‘suspect battery’.
Hi @rando_specs, Thank you for getting in touch with us.
We recommend upgrading the BMS version of all batteries to the latest version. It seems you have already received the update, is that correct? Please ensure that only one battery is connected at a time for the upgrade.
After upgrading the BMS, a battery recalibration is required.
You can calibrate any suspicious battery individually, while the other three can be calibrated simultaneously. Once all the batteries have consistent charge levels, you can reconnect and use them together.
Thank you @BLUETTI_CARE
Updated the other 3 batteries, did a complete drain and recharge of all 4 batteries at the same time and so far it’s looking better.
One battery pack is draining a little faster than the others but i’ll take it for now! Hopefully it’ll correct itself in the next few days.
Thank you for all your help!
@TheQuickFox Thank you as well for all the suggestions!