after I added to my system (AC500 + 4x B300S) two more B300S batteries,
the batteries are extremely unbalanced.
…
Please see the photo and the figure: I started with 100% for all batteries.
After a few days with overall SOC between 55 - 85 % there are now (SOC is 58%)
two nearly full batteries (94%), one completely (0%, for the second day) and one nearly empty (8%).
Obviously there is no significant current between the batteries or precisely, towards the empty batteries.
…
All batteries have the same BMS 1022,09.
Checking for updates I’m told that there is none - but I read in the forum that there is the version 1022,14. Software Update Notification for B300 and B300S
They say only for SN AC5002247, AC5002248.
My SN is AC5002308.
…
How can I get the new software for the batteries?
Will it help?
…
Otherwise, I must buy a T500 adapter to recalibrate each single battery.
Though I’m not convinced that it will help because, as I said at the beginning,
the problem got worse with 6 batteries. (Even with 4 batteries, it was not
well balanced.)
…
Now with one or nearly two batteries empty I’m anxious that it can reduce
their life time.
Try to charge all of them to 100%. If one of the batteries fails to accept a charge, try connecting it to your AC500 alone. You can use the Bluetti App to check if your power station or batteries have a firmware update available. Connect via bluetooth.
You can mention here all the serial numbers of your AC500 device and all batteries and then @mention Bluetti support employee to have them verify if you have the latest firmwares for your hardware revisions.
Please read this thread for tips on getting this issue resolved. It’s with an AC300 but those devices are very much similar.
This includes a realibration of every battery, where it is important that every battery reaches full state, 100% with no more charging and 0%, until the AC500 shuts down. Don’t leave the batteries empty after a full discharge. Recharge them again.
If that does not help, ask support for more options.
It is normal that there are some differences between battery SoC levels, roughly 10% to 20%, but having one at 0% and others ate 94% is bad…
Hi @digait, We have arranged a firmware upgrade for you, and the latest BMS updates will be pushed to your device within 24 hours. Please upgrade the firmware tomorrow.
When updating, ensure only one battery is connected at a time, as each B300S battery needs to be updated individually. After all of them are updated, calibrate the battery. This should help resolve the issue.
Please follow the steps below to recalibrate it:
Please discharge all the power (charge AC & DC appliances with the power station) 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 in charge.
This is the first I heard about waiting 3 hours for cooldown. I thought it was bad to leave them discharged for too long.
.
Since it’s winter electric heaters are HUGE power drains and good for discharging batteries. In fact, I should recalibrate mine as I have 3 heaters.
.
You might want to point out to them that don’t just go by the SOC reading 0%; discharge it until the AC500 shuts down on it’s own.
Hi @St8kout, Yes, after a complete discharge, enough cooling time is needed.
Even in cold winter, the internal temperature of the battery can still rise significantly due to its operation, and the heat dissipation is slower because of the casing.
Thank you for your addition, it is very helpful and provides valuable insights.
Burn them all down to zero and the ac500 actually shut off. Then charge back up. Supposedly, every time you add a new battery, to calibrate them all together, you need to drain them all , shut-off, and then recharge back up to 100.
Works for me, just sayin.
